Java教程
51.第十一章 进程和计划任务(三)
本文主要是介绍51.第十一章 进程和计划任务(三)，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！
2.10 进程对应的内存映射 pmap
格式：
pmap [options] pid [...]
常用选项
-x: 显示详细格式的信息
范例：
[root@rocky8 ~]# pmap 1 1: /usr/lib/systemd/systemd --switched-root --system --deserialize 17 000055b2f93c0000 1288K r-x-- systemd 000055b2f9701000 244K r---- systemd 000055b2f973e000 4K rw--- systemd 000055b2fb61d000 3796K rw--- [ anon ] 00007f5244000000 132K rw--- [ anon ] 00007f5244021000 65404K ----- [ anon ] 00007f524b7ae000 4K ----- [ anon ] 00007f524b7af000 8192K rw--- [ anon ] 00007f524bfaf000 4K ----- [ anon ] 00007f524bfb0000 8192K rw--- [ anon ] 00007f524c7b0000 132K r-x-- libnl-3.so.200.26.0 00007f524c7d1000 2044K ----- libnl-3.so.200.26.0 00007f524c9d0000 8K r---- libnl-3.so.200.26.0 00007f524c9d2000 4K rw--- libnl-3.so.200.26.0 00007f524c9d3000 492K r-x-- libnl-route-3.so.200.26.0 00007f524ca4e000 2048K ----- libnl-route-3.so.200.26.0 00007f524cc4e000 16K r---- libnl-route-3.so.200.26.0 00007f524cc52000 20K rw--- libnl-route-3.so.200.26.0 00007f524cc57000 8K rw--- [ anon ] 00007f524cc59000 120K r-x-- libibverbs.so.1.11.32.0 00007f524cc77000 2044K ----- libibverbs.so.1.11.32.0 00007f524ce76000 4K r---- libibverbs.so.1.11.32.0 00007f524ce77000 4K rw--- libibverbs.so.1.11.32.0 00007f524ce78000 1540K r-x-- libm-2.28.so 00007f524cff9000 2044K ----- libm-2.28.so 00007f524d1f8000 4K r---- libm-2.28.so 00007f524d1f9000 4K rw--- libm-2.28.so 00007f524d1fa000 580K r-x-- libudev.so.1.6.11 00007f524d28b000 2048K ----- libudev.so.1.6.11 00007f524d48b000 16K r---- libudev.so.1.6.11 00007f524d48f000 4K rw--- libudev.so.1.6.11 00007f524d490000 696K r-x-- libsepol.so.1 00007f524d53e000 2048K ----- libsepol.so.1 00007f524d73e000 4K r---- libsepol.so.1 00007f524d73f000 4K rw--- libsepol.so.1 00007f524d740000 8K rw--- [ anon ] 00007f524d742000 1524K r-x-- libunistring.so.2.1.0 00007f524d8bf000 2044K ----- libunistring.so.2.1.0 00007f524dabe000 16K r---- libunistring.so.2.1.0 00007f524dac2000 4K rw--- libunistring.so.2.1.0 00007f524dac3000 288K r-x-- libpcap.so.1.9.1 00007f524db0b000 2048K ----- libpcap.so.1.9.1 00007f524dd0b000 8K r---- libpcap.so.1.9.1 00007f524dd0d000 4K rw--- libpcap.so.1.9.1 00007f524dd0e000 124K r-x-- libgpg-error.so.0.24.2 00007f524dd2d000 2048K ----- libgpg-error.so.0.24.2 00007f524df2d000 4K r---- libgpg-error.so.0.24.2 00007f524df2e000 4K rw--- libgpg-error.so.0.24.2 00007f524df2f000 56K r-x-- libjson-c.so.4.0.0 00007f524df3d000 2048K ----- libjson-c.so.4.0.0 00007f524e13d000 4K r---- libjson-c.so.4.0.0 00007f524e13e000 4K rw--- libjson-c.so.4.0.0 00007f524e13f000 340K r-x-- libdevmapper.so.1.02 00007f524e194000 2044K ----- libdevmapper.so.1.02 00007f524e393000 8K r---- libdevmapper.so.1.02 00007f524e395000 12K rw--- libdevmapper.so.1.02 00007f524e398000 4K rw--- [ anon ] 00007f524e399000 16K r-x-- libattr.so.1.1.2448 00007f524e39d000 2048K ----- libattr.so.1.1.2448 00007f524e59d000 4K r---- libattr.so.1.1.2448 00007f524e59e000 4K rw--- [ anon ] 00007f524e59f000 2764K r-x-- libcrypto.so.1.1.1g 00007f524e852000 2044K ----- libcrypto.so.1.1.1g 00007f524ea51000 176K r---- libcrypto.so.1.1.1g 00007f524ea7d000 16K rw--- libcrypto.so.1.1.1g 00007f524ea81000 16K rw--- [ anon ] 00007f524ea85000 540K r-x-- libssl.so.1.1.1g 00007f524eb0c000 2044K ----- libssl.so.1.1.1g 00007f524ed0b000 36K r---- libssl.so.1.1.1g 00007f524ed14000 16K rw--- libssl.so.1.1.1g 00007f524ed18000 4K rw--- [ anon ] 00007f524ed19000 88K r-x-- libz.so.1.2.11 00007f524ed2f000 2044K ----- libz.so.1.2.11 00007f524ef2e000 4K r---- libz.so.1.2.11 00007f524ef2f000 4K rw--- [ anon ] 00007f524ef30000 20K r-x-- libcap-ng.so.0.0.0 00007f524ef35000 2044K ----- libcap-ng.so.0.0.0 00007f524f134000 4K r---- libcap-ng.so.0.0.0 00007f524f135000 4K rw--- libcap-ng.so.0.0.0 00007f524f136000 24K r-x-- libuuid.so.1.3.0 00007f524f13c000 2048K ----- libuuid.so.1.3.0 00007f524f33c000 4K r---- libuuid.so.1.3.0 00007f524f33d000 4K rw--- [ anon ] 00007f524f33e000 12K r-x-- libdl-2.28.so 00007f524f341000 2044K ----- libdl-2.28.so 00007f524f540000 4K r---- libdl-2.28.so 00007f524f541000 4K rw--- libdl-2.28.so 00007f524f542000 524K r-x-- libpcre2-8.so.0.7.1 00007f524f5c5000 2044K ----- libpcre2-8.so.0.7.1 00007f524f7c4000 4K r---- libpcre2-8.so.0.7.1 00007f524f7c5000 4K rw--- libpcre2-8.so.0.7.1 00007f524f7c6000 304K r-x-- libblkid.so.1.1.0 00007f524f812000 2048K ----- libblkid.so.1.1.0 00007f524fa12000 20K r---- libblkid.so.1.1.0 00007f524fa17000 4K rw--- libblkid.so.1.1.0 00007f524fa18000 4K rw--- [ anon ] 00007f524fa19000 112K r-x-- liblz4.so.1.8.3 00007f524fa35000 2044K ----- liblz4.so.1.8.3 00007f524fc34000 4K r---- liblz4.so.1.8.3 00007f524fc35000 4K rw--- [ anon ] 00007f524fc36000 148K r-x-- liblzma.so.5.2.4 00007f524fc5b000 2048K ----- liblzma.so.5.2.4 00007f524fe5b000 4K r---- liblzma.so.5.2.4 00007f524fe5c000 4K rw--- [ anon ] 00007f524fe5d000 112K r-x-- libidn2.so.0.3.6 00007f524fe79000 2048K ----- libidn2.so.0.3.6 00007f5250079000 4K r---- libidn2.so.0.3.6 00007f525007a000 4K rw--- [ anon ] 00007f525007b000 24K r-x-- libip4tc.so.2.0.0 00007f5250081000 2048K ----- libip4tc.so.2.0.0 00007f5250281000 4K r---- libip4tc.so.2.0.0 00007f5250282000 4K rw--- libip4tc.so.2.0.0 00007f5250283000 1120K r-x-- libgcrypt.so.20.2.5 00007f525039b000 2044K ----- libgcrypt.so.20.2.5 00007f525059a000 8K r---- libgcrypt.so.20.2.5 00007f525059c000 20K rw--- libgcrypt.so.20.2.5 00007f52505a1000 476K r-x-- libcryptsetup.so.12.6.0 00007f5250618000 2044K ----- libcryptsetup.so.12.6.0 00007f5250817000 8K r---- libcryptsetup.so.12.6.0 00007f5250819000 8K rw--- libcryptsetup.so.12.6.0 00007f525081b000 32K r-x-- libacl.so.1.1.2253 00007f5250823000 2044K ----- libacl.so.1.1.2253 00007f5250a22000 4K r---- libacl.so.1.1.2253 00007f5250a23000 4K rw--- libacl.so.1.1.2253 00007f5250a24000 16K r-x-- libcap.so.2.26 00007f5250a28000 2048K ----- libcap.so.2.26 00007f5250c28000 4K r---- libcap.so.2.26 00007f5250c29000 4K rw--- libcap.so.2.26 00007f5250c2a000 1776K r-x-- libc-2.28.so 00007f5250de6000 2044K ----- libc-2.28.so 00007f5250fe5000 16K r---- libc-2.28.so 00007f5250fe9000 8K rw--- libc-2.28.so 00007f5250feb000 16K rw--- [ anon ] 00007f5250fef000 108K r-x-- libpthread-2.28.so 00007f525100a000 2044K ----- libpthread-2.28.so 00007f5251209000 4K r---- libpthread-2.28.so 00007f525120a000 4K rw--- libpthread-2.28.so 00007f525120b000 16K rw--- [ anon ] 00007f525120f000 92K r-x-- libgcc_s-8-20200928.so.1 00007f5251226000 2044K ----- libgcc_s-8-20200928.so.1 00007f5251425000 4K r---- libgcc_s-8-20200928.so.1 00007f5251426000 4K rw--- libgcc_s-8-20200928.so.1 00007f5251427000 92K r-x-- libkmod.so.2.3.3 00007f525143e000 2044K ----- libkmod.so.2.3.3 00007f525163d000 4K r---- libkmod.so.2.3.3 00007f525163e000 4K rw--- libkmod.so.2.3.3 00007f525163f000 116K r-x-- libaudit.so.1.0.0 00007f525165c000 2044K ----- libaudit.so.1.0.0 00007f525185b000 4K r---- libaudit.so.1.0.0 00007f525185c000 4K rw--- libaudit.so.1.0.0 00007f525185d000 48K rw--- [ anon ] 00007f5251869000 56K r-x-- libpam.so.0.84.2 00007f5251877000 2048K ----- libpam.so.0.84.2 00007f5251a77000 4K r---- libpam.so.0.84.2 00007f5251a78000 4K rw--- libpam.so.0.84.2 00007f5251a79000 340K r-x-- libmount.so.1.1.0 00007f5251ace000 2048K ----- libmount.so.1.1.0 00007f5251cce000 12K r---- libmount.so.1.1.0 00007f5251cd1000 4K rw--- libmount.so.1.1.0 00007f5251cd2000 4K rw--- [ anon ] 00007f5251cd3000 156K r-x-- libselinux.so.1 00007f5251cfa000 2044K ----- libselinux.so.1 00007f5251ef9000 4K r---- libselinux.so.1 00007f5251efa000 4K rw--- libselinux.so.1 00007f5251efb000 8K rw--- [ anon ] 00007f5251efd000 120K r-x-- libseccomp.so.2.5.1 00007f5251f1b000 2048K ----- libseccomp.so.2.5.1 00007f525211b000 4K r---- libseccomp.so.2.5.1 00007f525211c000 4K rw--- libseccomp.so.2.5.1 00007f525211d000 28K r-x-- librt-2.28.so 00007f5252124000 2044K ----- librt-2.28.so 00007f5252323000 4K r---- librt-2.28.so 00007f5252324000 4K rw--- librt-2.28.so 00007f5252325000 2068K r-x-- libsystemd-shared-239.so 00007f525252a000 2048K ----- libsystemd-shared-239.so 00007f525272a000 564K r---- libsystemd-shared-239.so 00007f52527b7000 4K rw--- libsystemd-shared-239.so 00007f52527b8000 8K rw--- [ anon ] 00007f52527ba000 176K r-x-- ld-2.28.so 00007f52529ce000 72K rw--- [ anon ] 00007f52529e4000 8K rw--- [ anon ] 00007f52529e6000 4K r---- ld-2.28.so 00007f52529e7000 8K rw--- ld-2.28.so 00007ffc98722000 132K rw--- [ stack ] 00007ffc9875e000 16K r---- [ anon ] 00007ffc98762000 8K r-x-- [ anon ] ffffffffff600000 4K r-x-- [ anon ] total 186032K
另外一种实现
cat /proc/PID/maps
范例:
[root@rocky8 ~]# echo $BASHPID
10189
[root@rocky8 ~]# pmap 10189
10189: -bash
0000564515c68000 1056K r-x-- bash
0000564515f6f000 16K r---- bash
0000564515f73000 36K rw--- bash
0000564515f7c000 40K rw--- [ anon ]
00005645167b3000 396K rw--- [ anon ]
00007f79df02d000 2528K r---- LC_COLLATE
00007f79df2a5000 44K r-x-- libnss_files-2.28.so
00007f79df2b0000 2048K ----- libnss_files-2.28.so
00007f79df4b0000 4K r---- libnss_files-2.28.so
00007f79df4b1000 4K rw--- libnss_files-2.28.so
00007f79df4b2000 24K rw--- [ anon ]
00007f79df4b8000 9040K r--s- passwd (deleted)
00007f79dfd8c000 40K r-x-- libnss_sss.so.2
00007f79dfd96000 2044K ----- libnss_sss.so.2
00007f79dff95000 4K r---- libnss_sss.so.2
00007f79dff96000 4K rw--- libnss_sss.so.2
00007f79dff97000 1776K r-x-- libc-2.28.so
00007f79e0153000 2044K ----- libc-2.28.so
00007f79e0352000 16K r---- libc-2.28.so
00007f79e0356000 8K rw--- libc-2.28.so
00007f79e0358000 16K rw--- [ anon ]
00007f79e035c000 12K r-x-- libdl-2.28.so
00007f79e035f000 2044K ----- libdl-2.28.so
00007f79e055e000 4K r---- libdl-2.28.so
00007f79e055f000 4K rw--- libdl-2.28.so
00007f79e0560000 164K r-x-- libtinfo.so.6.1
00007f79e0589000 2044K ----- libtinfo.so.6.1
00007f79e0788000 16K r---- libtinfo.so.6.1
00007f79e078c000 4K rw--- libtinfo.so.6.1
00007f79e078d000 176K r-x-- ld-2.28.so
00007f79e0950000 332K r---- LC_CTYPE
00007f79e09a3000 4K r---- LC_NUMERIC
00007f79e09a4000 4K r---- LC_TIME
00007f79e09a5000 4K r---- LC_MONETARY
00007f79e09a6000 4K r---- SYS_LC_MESSAGES
00007f79e09a7000 4K r---- LC_PAPER
00007f79e09a8000 4K r---- LC_NAME
00007f79e09a9000 28K r--s- gconv-modules.cache
00007f79e09b0000 20K rw--- [ anon ]
00007f79e09b5000 4K r---- LC_ADDRESS
00007f79e09b6000 4K r---- LC_TELEPHONE
00007f79e09b7000 4K r---- LC_MEASUREMENT
00007f79e09b8000 4K r---- LC_IDENTIFICATION
00007f79e09b9000 4K r---- ld-2.28.so
00007f79e09ba000 8K rw--- ld-2.28.so
00007fffaa035000 132K rw--- [ stack ]
00007fffaa0c3000 16K r---- [ anon ]
00007fffaa0c7000 8K r-x-- [ anon ]
ffffffffff600000 4K r-x-- [ anon ]
total 26248K
[root@rocky8 ~]# cat /proc/10189/maps
564515c68000-564515d70000 r-xp 00000000 08:02 17502 /usr/bin/bash
564515f6f000-564515f73000 r--p 00107000 08:02 17502 /usr/bin/bash
564515f73000-564515f7c000 rw-p 0010b000 08:02 17502 /usr/bin/bash
564515f7c000-564515f86000 rw-p 00000000 00:00 0
5645167b3000-564516816000 rw-p 00000000 00:00 0 [heap]
7f79df02d000-7f79df2a5000 r--p 00000000 08:02 134352575 /usr/lib/locale/en_US.utf8/LC_COLLATE
7f79df2a5000-7f79df2b0000 r-xp 00000000 08:02 67117920 /usr/lib64/libnss_files-2.28.so
7f79df2b0000-7f79df4b0000 ---p 0000b000 08:02 67117920 /usr/lib64/libnss_files-2.28.so
7f79df4b0000-7f79df4b1000 r--p 0000b000 08:02 67117920 /usr/lib64/libnss_files-2.28.so
7f79df4b1000-7f79df4b2000 rw-p 0000c000 08:02 67117920 /usr/lib64/libnss_files-2.28.so
7f79df4b2000-7f79df4b8000 rw-p 00000000 00:00 0
7f79df4b8000-7f79dfd8c000 r--s 00000000 08:02 201328529 /var/lib/sss/mc/passwd (deleted)
7f79dfd8c000-7f79dfd96000 r-xp 00000000 08:02 67750436 /usr/lib64/libnss_sss.so.2
7f79dfd96000-7f79dff95000 ---p 0000a000 08:02 67750436 /usr/lib64/libnss_sss.so.2
7f79dff95000-7f79dff96000 r--p 00009000 08:02 67750436 /usr/lib64/libnss_sss.so.2
7f79dff96000-7f79dff97000 rw-p 0000a000 08:02 67750436 /usr/lib64/libnss_sss.so.2
7f79dff97000-7f79e0153000 r-xp 00000000 08:02 67117908 /usr/lib64/libc-2.28.so
7f79e0153000-7f79e0352000 ---p 001bc000 08:02 67117908 /usr/lib64/libc-2.28.so
7f79e0352000-7f79e0356000 r--p 001bb000 08:02 67117908 /usr/lib64/libc-2.28.so
7f79e0356000-7f79e0358000 rw-p 001bf000 08:02 67117908 /usr/lib64/libc-2.28.so
7f79e0358000-7f79e035c000 rw-p 00000000 00:00 0
7f79e035c000-7f79e035f000 r-xp 00000000 08:02 67117910 /usr/lib64/libdl-2.28.so
7f79e035f000-7f79e055e000 ---p 00003000 08:02 67117910 /usr/lib64/libdl-2.28.so
7f79e055e000-7f79e055f000 r--p 00002000 08:02 67117910 /usr/lib64/libdl-2.28.so
7f79e055f000-7f79e0560000 rw-p 00003000 08:02 67117910 /usr/lib64/libdl-2.28.so
7f79e0560000-7f79e0589000 r-xp 00000000 08:02 67117821 /usr/lib64/libtinfo.so.6.1
7f79e0589000-7f79e0788000 ---p 00029000 08:02 67117821 /usr/lib64/libtinfo.so.6.1
7f79e0788000-7f79e078c000 r--p 00028000 08:02 67117821 /usr/lib64/libtinfo.so.6.1
7f79e078c000-7f79e078d000 rw-p 0002c000 08:02 67117821 /usr/lib64/libtinfo.so.6.1
7f79e078d000-7f79e07b9000 r-xp 00000000 08:02 67117901 /usr/lib64/ld-2.28.so
7f79e0950000-7f79e09a3000 r--p 00000000 08:02 134352640 /usr/lib/locale/en_US.utf8/LC_CTYPE
7f79e09a3000-7f79e09a4000 r--p 00000000 08:02 134352643 /usr/lib/locale/en_US.utf8/LC_NUMERIC
7f79e09a4000-7f79e09a5000 r--p 00000000 08:02 201334461 /usr/lib/locale/en_US.utf8/LC_TIME
7f79e09a5000-7f79e09a6000 r--p 00000000 08:02 201334459 /usr/lib/locale/en_US.utf8/LC_MONETARY
7f79e09a6000-7f79e09a7000 r--p 00000000 08:02 201334471 /usr/lib/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES
7f79e09a7000-7f79e09a8000 r--p 00000000 08:02 67117882 /usr/lib/locale/en_US.utf8/LC_PAPER
7f79e09a8000-7f79e09a9000 r--p 00000000 08:02 134352642 /usr/lib/locale/en_US.utf8/LC_NAME
7f79e09a9000-7f79e09b0000 r--s 00000000 08:02 67152228 /usr/lib64/gconv/gconv-modules.cache
7f79e09b0000-7f79e09b5000 rw-p 00000000 00:00 0
7f79e09b5000-7f79e09b6000 r--p 00000000 08:02 201334456 /usr/lib/locale/en_US.utf8/LC_ADDRESS
7f79e09b6000-7f79e09b7000 r--p 00000000 08:02 201334460 /usr/lib/locale/en_US.utf8/LC_TELEPHONE
7f79e09b7000-7f79e09b8000 r--p 00000000 08:02 201334458 /usr/lib/locale/en_US.utf8/LC_MEASUREMENT
7f79e09b8000-7f79e09b9000 r--p 00000000 08:02 201334457 /usr/lib/locale/en_US.utf8/LC_IDENTIFICATION
7f79e09b9000-7f79e09ba000 r--p 0002c000 08:02 67117901 /usr/lib64/ld-2.28.so
7f79e09ba000-7f79e09bc000 rw-p 0002d000 08:02 67117901 /usr/lib64/ld-2.28.so
7fffaa035000-7fffaa056000 rw-p 00000000 00:00 0 [stack]
7fffaa0c3000-7fffaa0c7000 r--p 00000000 00:00 0 [vvar]
7fffaa0c7000-7fffaa0c9000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]
#查看系统调用
[root@rocky8 ~]# strace ls
-bash: strace: command not found
[root@rocky8 ~]# dnf -y install strace
[root@rocky8 ~]# strace ls
execve("/usr/bin/ls", ["ls"], 0x7fff01663320 /* 24 vars */) = 0
brk(NULL) = 0x55e74733d000
arch_prctl(0x3001 /* ARCH_??? */, 0x7fff67de07f0) = -1 EINVAL (Invalid argument)
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=13475, ...}) = 0
mmap(NULL, 13475, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8ef000
close(3) = 0
openat(AT_FDCWD, "/lib64/libselinux.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200z\0\0\0\0\0\0"..., 832) = 832
lseek(3, 157168, SEEK_SET) = 157168
read(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32) = 32
fstat(3, {st_mode=S_IFREG|0755, st_size=168000, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f930d8ed000
lseek(3, 157168, SEEK_SET) = 157168
read(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32) = 32
mmap(NULL, 2266608, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f930d49d000
mprotect(0x7f930d4c4000, 2093056, PROT_NONE) = 0
mmap(0x7f930d6c3000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x26000) = 0x7f930d6c3000
mmap(0x7f930d6c5000, 5616, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f930d6c5000
close(3) = 0
openat(AT_FDCWD, "/lib64/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\300\30\0\0\0\0\0\0"..., 832) = 832
lseek(3, 15728, SEEK_SET) = 15728
read(3, "\4\0\0\0 \0\0\0\5\0\0\0GNU\0\1\0\0\300\4\0\0\0\30\0\0\0\0\0\0\0"..., 48) = 48
fstat(3, {st_mode=S_IFREG|0755, st_size=24984, ...}) = 0
lseek(3, 15728, SEEK_SET) = 15728
read(3, "\4\0\0\0 \0\0\0\5\0\0\0GNU\0\1\0\0\300\4\0\0\0\30\0\0\0\0\0\0\0"..., 48) = 48
mmap(NULL, 2117944, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f930d297000
mprotect(0x7f930d29b000, 2097152, PROT_NONE) = 0
mmap(0x7f930d49b000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x4000) = 0x7f930d49b000
close(3) = 0
openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\2605\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=3168120, ...}) = 0
lseek(3, 808, SEEK_SET) = 808
read(3, "\4\0\0\0 \0\0\0\5\0\0\0GNU\0\1\0\0\300\4\0\0\0\330\1\0\0\0\0\0\0"..., 48) = 48
mmap(NULL, 3950400, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f930ced2000
mprotect(0x7f930d08e000, 2093056, PROT_NONE) = 0
mmap(0x7f930d28d000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1bb000) = 0x7f930d28d000
mmap(0x7f930d293000, 14144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f930d293000
close(3) = 0
openat(AT_FDCWD, "/lib64/libpcre2-8.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200#\0\0\0\0\0\0"..., 832) = 832
lseek(3, 532976, SEEK_SET) = 532976
read(3, "\4\0\0\0 \0\0\0\5\0\0\0GNU\0\1\0\0\300\4\0\0\0\30\0\0\0\0\0\0\0"..., 48) = 48
fstat(3, {st_mode=S_IFREG|0755, st_size=543152, ...}) = 0
lseek(3, 532976, SEEK_SET) = 532976
read(3, "\4\0\0\0 \0\0\0\5\0\0\0GNU\0\1\0\0\300\4\0\0\0\30\0\0\0\0\0\0\0"..., 48) = 48
mmap(NULL, 2634280, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f930cc4e000
mprotect(0x7f930ccd1000, 2093056, PROT_NONE) = 0
mmap(0x7f930ced0000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x82000) = 0x7f930ced0000
close(3) = 0
openat(AT_FDCWD, "/lib64/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\320\20\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=28968, ...}) = 0
mmap(NULL, 2109744, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f930ca4a000
mprotect(0x7f930ca4d000, 2093056, PROT_NONE) = 0
mmap(0x7f930cc4c000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f930cc4c000
close(3) = 0
openat(AT_FDCWD, "/lib64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200n\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=320504, ...}) = 0
mmap(NULL, 2225344, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f930c82a000
mprotect(0x7f930c845000, 2093056, PROT_NONE) = 0
mmap(0x7f930ca44000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1a000) = 0x7f930ca44000
mmap(0x7f930ca46000, 13504, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f930ca46000
close(3) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f930d8eb000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f930d8e9000
arch_prctl(ARCH_SET_FS, 0x7f930d8ec640) = 0
mprotect(0x7f930d28d000, 16384, PROT_READ) = 0
mprotect(0x7f930ca44000, 4096, PROT_READ) = 0
mprotect(0x7f930cc4c000, 4096, PROT_READ) = 0
mprotect(0x7f930ced0000, 4096, PROT_READ) = 0
mprotect(0x7f930d49b000, 4096, PROT_READ) = 0
mprotect(0x7f930d6c3000, 4096, PROT_READ) = 0
mprotect(0x55e745d4d000, 8192, PROT_READ) = 0
mprotect(0x7f930d8f3000, 4096, PROT_READ) = 0
munmap(0x7f930d8ef000, 13475) = 0
set_tid_address(0x7f930d8ec910) = 15182
set_robust_list(0x7f930d8ec920, 24) = 0
rt_sigaction(SIGRTMIN, {sa_handler=0x7f930c830900, sa_mask=[], sa_flags=SA_RESTORER|SA_SIGINFO, sa_restorer=0x7f930c83cb30}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {sa_handler=0x7f930c830990, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, sa_restorer=0x7f930c83cb30}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
statfs("/sys/fs/selinux", 0x7fff67de07a0) = -1 ENOENT (No such file or directory)
statfs("/selinux", 0x7fff67de07a0) = -1 ENOENT (No such file or directory)
brk(NULL) = 0x55e74733d000
brk(0x55e74735e000) = 0x55e74735e000
openat(AT_FDCWD, "/proc/filesystems", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
read(3, "nodev\tsysfs\nnodev\ttmpfs\nnodev\tbd"..., 1024) = 334
read(3, "", 1024) = 0
close(3) = 0
access("/etc/selinux/config", F_OK) = 0
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=2997, ...}) = 0
read(3, "# Locale name alias data base.\n#"..., 4096) = 2997
read(3, "", 4096) = 0
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_IDENTIFICATION", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_IDENTIFICATION", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=368, ...}) = 0
mmap(NULL, 368, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8f2000
close(3) = 0
openat(AT_FDCWD, "/usr/lib64/gconv/gconv-modules.cache", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=26998, ...}) = 0
mmap(NULL, 26998, PROT_READ, MAP_SHARED, 3, 0) = 0x7f930d8e2000
close(3) = 0
futex(0x7f930d2929a8, FUTEX_WAKE_PRIVATE, 2147483647) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_MEASUREMENT", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_MEASUREMENT", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=23, ...}) = 0
mmap(NULL, 23, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8f1000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_TELEPHONE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_TELEPHONE", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=59, ...}) = 0
mmap(NULL, 59, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8f0000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_ADDRESS", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_ADDRESS", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=167, ...}) = 0
mmap(NULL, 167, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8ef000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_NAME", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_NAME", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=77, ...}) = 0
mmap(NULL, 77, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8e1000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_PAPER", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_PAPER", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=34, ...}) = 0
mmap(NULL, 34, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8e0000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_MESSAGES", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_MESSAGES", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFDIR|0755, st_size=29, ...}) = 0
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=57, ...}) = 0
mmap(NULL, 57, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8df000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_MONETARY", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_MONETARY", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=286, ...}) = 0
mmap(NULL, 286, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8de000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_COLLATE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_COLLATE", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=2586930, ...}) = 0
mmap(NULL, 2586930, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930c5b2000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_TIME", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_TIME", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=3316, ...}) = 0
mmap(NULL, 3316, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8dd000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_NUMERIC", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_NUMERIC", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=54, ...}) = 0
mmap(NULL, 54, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d8dc000
close(3) = 0
openat(AT_FDCWD, "/usr/lib/locale/en_US.UTF-8/LC_CTYPE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/en_US.utf8/LC_CTYPE", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=337024, ...}) = 0
mmap(NULL, 337024, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f930d889000
close(3) = 0
ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(1, TIOCGWINSZ, {ws_row=27, ws_col=143, ws_xpixel=0, ws_ypixel=0}) = 0
openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3
fstat(3, {st_mode=S_IFDIR|0550, st_size=251, ...}) = 0
getdents64(3, 0x55e747347980 /* 16 entries */, 32768) = 528
getdents64(3, 0x55e747347980 /* 0 entries */, 32768) = 0
close(3) = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x2), ...}) = 0
write(1, " anaconda-ks.cfg 'aux |grep bas"..., 58 anaconda-ks.cfg 'aux |grep bashq' test.pipe test.sh
) = 58
close(1) = 0
close(2) = 0
exit_group(0) = ?
+++ exited with 0 +++
#查看库调用
[root@rocky8 ~]# ltrace ls
-bash: ltrace: command not found
[root@rocky8 ~]# dnf -y install ltrace
[root@rocky8 ~]# ltrace ls
strrchr("ls", '/') = nil
setlocale(LC_ALL, "") = "en_US.UTF-8"
bindtextdomain("coreutils", "/usr/share/locale") = "/usr/share/locale"
textdomain("coreutils") = "coreutils"
__cxa_atexit(0x5641524b4690, 0, 0x5641526c6f80, 0) = 0
isatty(1) = 1
getenv("QUOTING_STYLE") = nil
getenv("COLUMNS") = nil
ioctl(1, 21523, 0x7ffe9041e4b0) = 0
getenv("TABSIZE") = nil
getopt_long(1, 0x7ffe9041e5e8, "abcdfghiklmnopqrstuvw:xABCDFGHI:"..., 0x5641526c7280, -1) = -1
getenv("LS_BLOCK_SIZE") = nil
getenv("BLOCK_SIZE") = nil
getenv("BLOCKSIZE") = nil
getenv("POSIXLY_CORRECT") = nil
getenv("BLOCK_SIZE") = nil
__errno_location() = 0x7fe40a2454d8
malloc(56) = 0x5641538c39c0
memcpy(0x5641538c39c0, "\003\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 56) = 0x5641538c39c0
__errno_location() = 0x7fe40a2454d8
malloc(56) = 0x5641538c3a00
memcpy(0x5641538c3a00, "\003\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 56) = 0x5641538c3a00
getenv("TZ") = nil
malloc(128) = 0x5641538c3a40
malloc(20000) = 0x5641538c3ad0
malloc(32) = 0x5641538c8900
strlen(".") = 1
malloc(2) = 0x5641538c8930
memcpy(0x5641538c8930, ".\0", 2) = 0x5641538c8930
__errno_location() = 0x7fe40a2454d8
opendir(".") = { 3 }
readdir({ 3 }) = { 201326721, "." }
readdir({ 3 }) = { 128, ".." }
readdir({ 3 }) = { 201921796, ".bash_logout" }
readdir({ 3 }) = { 201921797, ".bash_profile" }
readdir({ 3 }) = { 201921798, ".bashrc" }
readdir({ 3 }) = { 201921799, ".cshrc" }
readdir({ 3 }) = { 201921800, ".tcshrc" }
readdir({ 3 }) = { 201326724, "anaconda-ks.cfg" }
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
strlen("anaconda-ks.cfg") = 15
strlen("anaconda-ks.cfg") = 15
malloc(16) = 0x5641538d0990
memcpy(0x5641538d0990, "anaconda-ks.cfg\0", 16) = 0x5641538d0990
readdir({ 3 }) = { 201929311, ".vimrc" }
readdir({ 3 }) = { 201929315, ".bash_history" }
readdir({ 3 }) = { 201327308, "test.pipe" }
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
strlen("test.pipe") = 9
strlen("test.pipe") = 9
malloc(10) = 0x5641538d09b0
memcpy(0x5641538d09b0, "test.pipe\0", 10) = 0x5641538d09b0
readdir({ 3 }) = { 67644000, ".config" }
readdir({ 3 }) = { 201328537, "aux |grep bashq" }
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
strlen("aux |grep bashq") = 15
malloc(16) = 0x5641538d09d0
memcpy(0x5641538d09d0, "aux |grep bashq\0", 16) = 0x5641538d09d0
readdir({ 3 }) = { 201328540, ".lesshst" }
readdir({ 3 }) = { 201328542, "test.sh" }
strlen("test.sh") = 7
malloc(8) = 0x5641538d09f0
memcpy(0x5641538d09f0, "test.sh\0", 8) = 0x5641538d09f0
readdir({ 3 }) = { 201328543, ".viminfo" }
readdir({ 3 }) = nil
closedir({ 3 }) = 0
free(nil) = <void>
malloc(96) = 0x5641538c8950
_setjmp(0x5641526c82a0, 0x400000, 0x5641538c3df0, 0x5641538c8970) = 0
__errno_location() = 0x7fe40a2454d8
strcoll("aux |grep bashq", "test.sh") = -116
__errno_location() = 0x7fe40a2454d8
strcoll("anaconda-ks.cfg", "test.pipe") = -116
memcpy(0x5641538c8978, "\230;\214SAV\0\0", 8) = 0x5641538c8978
__errno_location() = 0x7fe40a2454d8
strcoll("anaconda-ks.cfg", "aux |grep bashq") = -2
__errno_location() = 0x7fe40a2454d8
strcoll("test.pipe", "aux |grep bashq") = 116
__errno_location() = 0x7fe40a2454d8
strcoll("test.pipe", "test.sh") = -1
realloc(nil, 192) = 0x5641538c89c0
malloc(288) = 0x5641538c8a90
strlen("anaconda-ks.cfg") = 15
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
strlen("test.pipe") = 9
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
strlen("test.sh") = 7
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
strlen("anaconda-ks.cfg") = 15
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
strlen("anaconda-ks.cfg") = 15
__overflow(0x7fe409beb6e0, 32, 0x5641538d0990, 16) = 32
fwrite_unlocked("anaconda-ks.cfg", 1, 15, 0x7fe409beb6e0) = 15
__overflow(0x7fe409beb6e0, 32, 1, 8) = 32
__overflow(0x7fe409beb6e0, 32, 2, 8) = 32
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
fwrite_unlocked("'aux |grep bashq'", 1, 17, 0x7fe409beb6e0) = 17
__overflow(0x7fe409beb6e0, 32, 4, 8) = 32
__overflow(0x7fe409beb6e0, 32, 5, 8) = 32
strlen("test.pipe") = 9
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
strlen("test.pipe") = 9
__overflow(0x7fe409beb6e0, 32, 0x5641538d09b0, 16) = 32
fwrite_unlocked("test.pipe", 1, 9, 0x7fe409beb6e0) = 9
__overflow(0x7fe409beb6e0, 32, 0, 8) = 32
__overflow(0x7fe409beb6e0, 32, 1, 8) = 32
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
strlen("test.sh") = 7
__ctype_get_mb_cur_max() = 6
__ctype_get_mb_cur_max() = 6
__errno_location() = 0x7fe40a2454d8
__ctype_get_mb_cur_max() = 6
strlen("test.sh") = 7
__overflow(0x7fe409beb6e0, 32, 0x5641538d09f0, 16) = 32
fwrite_unlocked("test.sh", 1, 7, 0x7fe409beb6e0) = 7
__overflow(0x7fe409beb6e0, 10, 7, 0 anaconda-ks.cfg 'aux |grep bashq' test.pipe test.sh
) = 10
free(0x5641538c8930) = <void>
free(nil) = <void>
free(0x5641538c8900) = <void>
__fpending(0x7fe409beb6e0, 0, 0x5641524b4690, 1) = 0
fileno(0x7fe409beb6e0) = 1
__freading(0x7fe409beb6e0, 0, 0x5641524b4690, 1) = 0
__freading(0x7fe409beb6e0, 0, 2052, 1) = 0
fflush(0x7fe409beb6e0) = 0
fclose(0x7fe409beb6e0) = 0
__fpending(0x7fe409beb600, 0, 0x7fe409be6880, 2880) = 0
fileno(0x7fe409beb600) = 2
__freading(0x7fe409beb600, 0, 0x7fe409be6880, 2880) = 0
__freading(0x7fe409beb600, 0, 4, 2880) = 0
fflush(0x7fe409beb600) = 0
fclose(0x7fe409beb600) = 0
__cxa_finalize(0x5641526c6f80, 0x5641526c6f78, 1, 1) = 0x7fe409bec8d8
+++ exited (status 0) +++
2.11 虚拟内存信息 vmstat
格式：
vmstat [options] [delay [count]]
显示项说明：
procs:
r：可运行（正运行或等待运行）进程的个数，和核心数有关
b：处于不可中断睡眠态的进程个数(被阻塞的队列的长度)
memory：
swpd: 交换内存的使用总量
free：空闲物理内存总量
buffer：用于buffer的内存总量
cache：用于cache的内存总量
swap:
si：从磁盘交换进内存的数据速率(kb/s)
so：从内存交换至磁盘的数据速率(kb/s)
io：
bi：从块设备读入数据到系统的速率(kb/s)
bo: 保存数据至块设备的速率
system：
in: interrupts 中断速率，包括时钟
cs: context switch 进程切换速率
cpu：
us:Time spent running non-kernel code
sy: Time spent running kernel code
id: Time spent idle. Linux 2.5.41前,包括IO-wait time.
wa: Time spent waiting for IO. 2.5.41前，包括in idle.
st: Time stolen from a virtual machine. 2.6.11前, unknown.
选项：
-s: 显示内存的统计数据
范例：
[root@rocky8 ~]# vmstat procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 161444 144140 0 204936 1 6 36 46 394 156 6 23 71 0 0 [root@rocky8 ~]# vmstat 1 3 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 161444 143636 0 204976 1 6 36 45 393 156 6 23 71 0 0 0 0 161444 143384 0 204976 0 0 0 0 173 271 0 0 100 0 0 0 0 161444 143384 0 204976 0 0 0 0 169 265 0 1 100 0 0 [root@rocky8 ~]# dd if=/dev/zero of=/dev/null bs=2G count=1 0+1 records in 0+1 records out 2147479552 bytes (2.1 GB, 2.0 GiB) copied, 4.86451 s, 441 MB/s #so 增长，swqp output 因为它是以memory 为参照物，它指的内存的出 [root@rocky8 ~]# vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 426476 607980 0 52244 1 70 37 109 395 156 6 23 71 0 0 ... 2 0 835492 44236 0 33704 1016 409848 3584 409897 23147 1293 0 76 24 0 0 2 0 1241576 45968 0 33896 592 406556 1732 406556 27253 750 0 84 16 0 0 2 0 1644304 42404 0 32484 468 403416 468 403416 27321 693 0 82 18 0 0 0 0 430124 630036 0 33852 684 340164 3940 340164 17841 994 0 64 36 0 0 [root@rocky8 ~]# dd if=/dev/sda of=/dev/null ^C31061791+0 records in 31061790+0 records out 15903636480 bytes (16 GB, 15 GiB) copied, 15.417 s, 1.0 GB/s #bi 增长，它以内存为参照物 [root@rocky8 ~]# vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 429100 608712 0 53568 1 124 38 163 397 156 6 22 71 0 0 0 0 429100 608712 0 53628 12 0 12 0 170 278 0 0 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 152 234 0 0 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 155 256 0 1 99 0 0 0 0 429100 608712 0 53628 0 0 0 0 146 256 0 0 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 167 266 0 1 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 173 271 0 0 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 150 256 0 0 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 157 256 0 1 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 177 280 0 0 100 0 0 0 0 429100 608712 0 53628 0 0 0 0 165 255 0 1 99 0 0 1 0 429100 580228 28496 53624 52 0 28548 0 352 351 0 3 97 0 0 1 0 429100 80020 537308 44084 0 0 995328 0 3202 686 5 65 30 0 0 1 0 429100 63424 556916 41004 0 0 892928 0 2901 474 6 55 39 0 0 2 0 429100 48728 568692 41712 0 0 1007616 0 2841 491 7 54 39 0 0 1 0 429100 62404 555248 43736 0 0 1032208 0 2944 521 8 55 38 0 0 1 0 429100 51920 563480 46140 0 0 1015808 0 2953 563 6 56 38 0 0 1 0 429100 51112 563832 46468 0 0 1036288 0 3214 717 8 56 37 0 0 1 0 429100 59728 555264 46528 0 0 1019904 0 3272 782 8 54 38 0 0 1 0 429100 52792 561940 46688 0 0 1007616 0 3254 772 6 57 37 0 0 2 0 429100 54960 559708 46780 0 0 1032212 0 3250 735 7 56 37 0 0 1 0 429100 54464 560468 46456 0 0 1015808 0 3255 764 7 56 38 0 0 2 0 429100 58452 553540 46440 0 0 991232 0 3242 739 6 56 38 0 0 3 0 429100 66520 548476 46544 0 0 1007616 0 3256 760 7 56 38 0 0 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 429100 55688 558988 46664 0 0 1019904 0 3320 776 8 55 37 0 0 2 0 429100 61720 552588 46340 0 0 1019904 0 3292 786 7 56 37 0 0 1 0 429100 67816 545968 46516 0 0 1036288 0 3350 802 6 57 37 0 0 0 0 429100 64656 550028 46416 0 0 376832 0 1318 458 2 21 77 0 0 [root@rocky8 ~]# dd if=/dev/zero of=f1.img ^C7872812+0 records in 7872812+0 records out 4030879744 bytes (4.0 GB, 3.8 GiB) copied, 6.52304 s, 618 MB/s #bo 增长 [root@rocky8 ~]# vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 429100 66380 0 595296 1 123 575 488 398 157 6 22 71 0 0 0 0 429100 66380 0 595344 0 0 0 0 140 240 0 0 100 0 0 0 0 429100 66380 0 595344 0 0 0 0 143 254 0 0 100 0 0 0 0 429100 66380 0 595344 0 0 0 46931 271 274 0 3 97 0 0 0 0 429100 66380 0 595344 12 0 12 0 167 276 0 0 100 0 0 5 0 429100 148272 0 514036 0 0 16 423938 1812 385 5 54 41 0 0 1 0 429100 77728 0 584940 0 0 16 600099 2294 446 6 72 23 0 0 1 0 429100 65104 0 596288 0 0 0 593922 2351 490 6 71 23 0 0 1 0 429100 51764 0 609512 0 0 0 604076 2317 442 6 72 22 0 0 2 0 429100 52244 0 609060 0 0 0 614401 2408 494 6 74 20 0 0 2 0 429100 78452 0 582860 0 0 0 593920 2349 401 7 72 21 0 0 0 0 429100 64028 0 597024 0 0 0 450562 1941 427 4 56 40 0 0
范例：
[root@rocky8 ~]# vmstat -s
801164 K total memory
139904 K used memory
12636 K active memory
560876 K inactive memory
61304 K free memory
0 K buffer memory
599956 K swap cache
2097148 K total swap
429100 K used swap
1668048 K free swap
176209 non-nice user cpu ticks
305 nice user cpu ticks
616742 system cpu ticks
2077191 idle cpu ticks
243 IO-wait cpu ticks
7232 IRQ cpu ticks
24903 softirq cpu ticks
0 stolen cpu ticks
16632392 pages paged in
18105063 pages paged out
6432 pages swapped in
891099 pages swapped out
11526267 interrupts
4544888 CPU context switches
1635656624 boot time
15629 forks
2.12 统计CPU和设备IO信息 iostat
此工具由sysstat包提供
范例：
[root@rocky8 ~]# iostat
Linux 4.18.0-305.3.1.el8_4.x86_64 (rocky8) 10/31/2021 _x86_64_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
6.05 0.01 22.29 0.01 0.00 71.64
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
scd0 0.00 0.06 0.00 1041 0
sda 4.90 955.22 1039.76 16633034 18105087
[root@rocky8 ~]# iostat 1
Linux 4.18.0-305.3.1.el8_4.x86_64 (rocky8) 10/31/2021 _x86_64_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
6.04 0.01 22.25 0.01 0.00 71.69
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
scd0 0.00 0.06 0.00 1041 0
sda 4.89 953.73 1038.14 16633046 18105090
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.50 0.00 0.00 99.50
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
scd0 0.00 0.00 0.00 0 0
sda 0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.50 0.00 0.00 99.50
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
scd0 0.00 0.00 0.00 0 0
sda 0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.00 0.00 0.00 100.00
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
scd0 0.00 0.00 0.00 0 0
sda 1.00 4.00 0.00 4 0
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.50 0.00 0.00 99.50
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
scd0 0.00 0.00 0.00 0 0
sda 0.00 0.00 0.00 0 0
^C
[root@rocky8 ~]# iostat /dev/sda
Linux 4.18.0-305.3.1.el8_4.x86_64 (rocky8) 10/31/2021 _x86_64_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
6.03 0.01 22.20 0.01 0.00 71.76
Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 4.88 951.90 1036.14 16633050 18105155
[root@rocky8 ~]# iostat /dev/sda |awk /sda/'{print $2.$3.$4}'
4.88951.061035.23
[root@rocky8 ~]# iostat /dev/sda |grep sda|tr -s ' '|cut -d" " -f2-7
4.88 950.86 1034.74 16637426 18105157
2.13 系统资源统计 dstat
dstat由pcp-system-tools包提供，用于代替 vmstat,iostat功能
格式：
dstat [-afv] [options..] [delay [count]]
常用选项
-c 显示cpu相关信息 -C #,#,...,total -d 显示disk相关信息 -D total,sda,sdb,... -g 显示page相关统计数据 -m 显示memory相关统计数据 -n 显示network相关统计数据 -p 显示process相关统计数据 -r 显示io请求相关的统计数据 -s 显示swapped相关的统计数据 --tcp --udp --unix --raw --socket --ipc --top-cpu：显示最占用CPU的进程 --top-io: 显示最占用io的进程 --top-mem: 显示最占用内存的进程 --top-latency: 显示延迟最大的进程
范例：
[root@rocky8 ~]# dstat -bash: dstat: command not found [root@rocky8 ~]# dnf -y install dstat [root@rocky8 ~]# dstat You did not select any stats, using -cdngy by default. ----total-usage---- -dsk/total- -net/total- ---paging-- ---system-- usr sys idl wai stl| read writ| recv send| in out | int csw 1 0 100 0 0| 0 0 | 60B 617B| 0 0 | 199 327 0 0 100 0 0| 0 0 | 60B 314B| 0 0 | 190 317 0 0 99 0 0| 0 0 | 60B 314B| 0 0 | 182 303 0 0 99 0 0| 0 0 | 60B 314B| 0 0 | 188 314 0 0 99 0 0| 0 0 | 60B 314B| 0 0 | 187 319 0 0 100 0 0| 0 0 | 60B 314B| 0 0 | 200 330 0 0 99 0 0| 0 0 | 60B 314B| 0 0 | 179 306 1 0 99 0 0| 0 0 | 60B 314B| 0 0 | 181 298 0 0 99 0 0| 0 0 | 166B 390B| 0 0 | 207 329 0 0 100 0 0| 0 0 | 60B 314B| 0 0 | 200 323 0 0 99 0 0| 0 0 | 60B 314B| 0 0 | 186 316 1 1 99 0 0| 0 1504k| 60B 314B| 0 0 | 215 333 ^C [root@rocky8 ~]# dstat 1 3 You did not select any stats, using -cdngy by default. ----total-usage---- -dsk/total- -net/total- ---paging-- ---system-- usr sys idl wai stl| read writ| recv send| in out | int csw 0 0 99 0 0| 0 0 | 60B 617B| 0 0 | 196 319 0 0 100 0 0| 0 0 | 60B 314B| 0 0 | 199 322 0 0 99 0 0| 0 0 | 60B 314B| 0 0 | 194 314 [root@rocky8 ~]# dd if=/dev/sda of=/dev/null [root@centos7 ~]# ping -f -s 65507 172.31.1.8 PING 172.31.1.8 (172.31.1.8) 65507(65535) bytes of data. [root@rocky8 ~]# dstat You did not select any stats, using -cdngy by default. ----total-usage---- -dsk/total- -net/total- ---paging-- ---system-- usr sys idl wai stl| read writ| recv send| in out | int csw 23 50 26 0 0| 910M 0 | 17M 17M| 0 0 |8224 977 24 49 27 0 0| 921M 0 | 17M 17M| 0 0 |8147 956 25 48 27 0 0| 912M 0 | 16M 16M| 0 0 |8054 895 24 49 26 0 0| 904M 0 | 17M 16M| 0 0 |8222 958 24 49 27 0 0| 908M 2049B| 17M 17M| 0 0 |8336 939 24 49 26 0 0| 892M 0 | 17M 17M| 0 0 |8249 931 24 48 27 0 0| 911M 0 | 16M 16M| 0 0 |8068 907 24 49 27 0 0| 887M 0 | 17M 17M| 0 0 |8283 895 24 49 28 0 0| 893M 0 | 17M 17M| 0 0 |8257 934 24 48 27 0 0| 872M 0 | 17M 17M| 0 0 |8110 913 24 49 26 0 0| 876M 0 | 16M 16M| 0 0 |7965 922 25 49 27 0 0| 892M 0 | 17M 17M| 0 0 |8122 942 22 49 26 0 0| 883M 0 | 17M 17M| 0 0 |7967 960 24 49 27 0 0| 917M 0 | 16M 16M| 0 0 |8254 962 ^C
2.14 监视磁盘I/O iotop
来自于iotop包
[root@rocky8 ~]# iotop -bash: iotop: command not found [root@rocky8 ~]# dnf -y install iotop
iotop命令是一个用来监视磁盘I/O使用状况的top类工具iotop具有与top相似的UI，其中包括PID、用户、I/O、进程等相关信息，可查看每个进程是如何使用IO
iotop输出
- 第一行：Read和Write速率总计
- 第二行：实际的Read和Write速率
- 第三行：参数如下：
线程ID（按p切换为进程ID）
优先级
用户
磁盘读速率
磁盘写速率
swap交换百分比
IO等待所占的百分比
iotop常用参数
-o, --only只显示正在产生I/O的进程或线程，除了传参，可以在运行过程中按o生效 -b, --batch非交互模式，一般用来记录日志 -n NUM, --iter=NUM设置监测的次数，默认无限。在非交互模式下很有用 -d SEC, --delay=SEC设置每次监测的间隔，默认1秒，接受非整形数据例如1.1 -p PID, --pid=PID指定监测的进程/线程 -u USER, --user=USER指定监测某个用户产生的I/O -P, --processes仅显示进程，默认iotop显示所有线程 -a, --accumulated显示累积的I/O，而不是带宽 -k, --kilobytes使用kB单位，而不是对人友好的单位。在非交互模式下，脚本编程有用 -t, --time 加上时间戳，非交互非模式 -q, --quiet 禁止头几行，非交互模式，有三种指定方式 -q 只在第一次监测时显示列名 -qq 永远不显示列名 -qqq 永远不显示I/O汇总
交互按键
left和right方向键：改变排序 r：反向排序 o：切换至选项--only p：切换至--processes选项 a：切换至--accumulated选项 q：退出 i：改变线程的优先级
范例：
[root@rocky8 ~]# iotop
Total DISK READ : 0.00 B/s | Total DISK WRITE : 0.00 B/s
Actual DISK READ: 0.00 B/s | Actual DISK WRITE: 0.00 B/s
TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND
1 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % systemd --switched-root --system --deserialize 17
2 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kthreadd]
3 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_gp]
4 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_par_gp]
6 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/0:0H-events_highpri]
9 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [mm_percpu_wq]
10 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/0]
11 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_sched]
12 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/0]
13 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/0]
14 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [cpuhp/0]
16 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kdevtmpfs]
17 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [netns]
18 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kauditd]
19 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [khungtaskd]
20 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [oom_reaper]
21 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [writeback]
22 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kcompactd0]
23 be/5 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksmd]
24 be/7 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [khugepaged]
25 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [crypto]
26 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kintegrityd]
27 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kblockd]
[root@rocky8 ~]# dd if=/dev/sda of=/dev/null
[root@rocky8 ~]# iotop
Total DISK READ : 907.52 M/s | Total DISK WRITE : 0.00 B/s
Actual DISK READ: 907.52 M/s | Actual DISK WRITE: 0.00 B/s
TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND
16132 be/4 root 907.52 M/s 0.00 B/s 0.00 % 0.00 % dd if=/dev/sda of=/dev/null
1 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % systemd --switched-root --system --deserialize 17
2 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kthreadd]
3 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_gp]
4 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_par_gp]
6 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/0:0H-events_highpri]
9 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [mm_percpu_wq]
10 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/0]
11 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_sched]
12 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/0]
13 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/0]
14 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [cpuhp/0]
16 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kdevtmpfs]
17 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [netns]
18 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kauditd]
19 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [khungtaskd]
20 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [oom_reaper]
21 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [writeback]
22 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kcompactd0]
23 be/5 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksmd]
24 be/7 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [khugepaged]
25 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [crypto]
26 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kintegrityd]
[root@rocky8 ~]# dd if=/dev/zero of=f1.img
[root@rocky8 ~]# iotop -n 1 |head -1
Total DISK READ : 0.00 B/s | Total DISK WRITE : 480.76 M/s
2.15 显示网络带宽使用情况 iftop
通过EPEL源安装iftop包
[root@rocky8 ~]# iftop -bash: iftop: command not found [root@rocky8 ~]# dnf -y install iftop [root@rocky8 ~]# iftop
范例：
[root@centos7 ~]# ping -f -s 65507 172.31.1.8
PING 172.31.1.8 (172.31.1.8) 65507(65535) bytes of data.
[root@rocky8 ~]# iftop
interface: eth0
IP address is: 172.31.1.8
MAC address is: 00:0c:29:f9:6a:d1
1.86Gb 3.73Gb 5.59Gb 7.45Gb 9.31Gb
└───────────────────────────┴────────────────────────────┴───────────────────────────┴────────────────────────────┴────────────────────────────
rocky8 => 172.31.0.7 85.8Mb 85.8Mb 85.8Mb
<= 85.9Mb 85.9Mb 85.9Mb
rocky8 => 172.31.0.1 8.62Kb 8.62Kb 8.62Kb
<= 920b 920b 920b
rocky8 => public1.alidns.com 1.07Kb 1.07Kb 1.07Kb
<= 2.10Kb 2.10Kb 2.10Kb
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
TX: cum: 36.6MB peak: 85.8Mb rates: 85.8Mb 85.8Mb 85.8Mb
RX: 36.7MB 85.9Mb 85.9Mb 85.9Mb 85.9Mb
[root@rocky8 ~]# 73.3MB 172Mb 172Mb 172Mb 172Mb
[root@rocky8 ~]# iftop -n #-n 纯数字显示
interface: eth0
IP address is: 172.31.1.8
MAC address is: 00:0c:29:f9:6a:d1
18.6Gb 37.3Gb 55.9Gb 74.5Gb 93.1Gb
└───────────────────────────┴────────────────────────────┴───────────────────────────┴────────────────────────────┴────────────────────────────
172.31.1.8 => 172.31.0.7 122Mb 122Mb 122Mb
<= 121Mb 123Mb 123Mb
172.31.1.8 => 172.31.0.1 3.09Kb 4.25Kb 4.25Kb
<= 368b 368b 368b
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
TX: cum: 61.3MB peak: 123Mb rates: 122Mb 123Mb 123Mb
RX: 61.3MB 124Mb 121Mb 123Mb 123Mb
[root@rocky8 ~]# 123MB 247Mb 243Mb 245Mb 245Mb
2.16 查看网络实时吞吐量 nload
[root@rocky8 ~]# nload -bash: nload: command not found [root@rocky8 ~]# dnf -y install nload [root@rocky8 ~]# nload
nload 是一个实时监控网络流量和带宽使用情况，以数值和动态图展示进出的流量情况,通过EPEL源安装
界面操作
上下方向键、左右方向键、enter键或者tab键都就可以切换查看多个网卡的流量情况 按 F2 显示选项窗口 按 q 或者 Ctrl+C 退出 nload
范例：
#默认只查看第一个网络的流量进出情况
[root@rocky8 ~]# nload
Device eth0 [172.31.1.8] (1/2):
===============================================================================================================================================
Incoming:
#
#
#
#
#
#
# Curr: 127.88 MBit/s
# Avg: 127.88 MBit/s
# Min: 127.88 MBit/s
# Max: 127.88 MBit/s
# Ttl: 24.98 GByte
Outgoing:
#
#
#
#
#
#
#
# Curr: 127.89 MBit/s
# Avg: 127.89 MBit/s
# Min: 127.89 MBit/s
# Max: 127.89 MBit/s
# Ttl: 25.64 GByte
...
#在nload后面指定网卡，可以指定多个,按左右键分别显示网卡状态
nload eth0 eth1
#设置刷新间隔：默认刷新间隔是100毫秒，可通过 -t 命令设置刷新时间（单位是毫秒）
nload -t 500 eth0
#设置单位：显示两种单位一种是显示Bit/s、一种是显示Byte/s，默认是以Bit/s，也可不显示/s
#-u h|b|k|m|g|H|B|K|M|G 表示的含义： h: auto, b: Bit/s, k: kBit/s, m: MBit/s, H:auto, B: Byte/s, K: kByte/s, M: MByte/s
nload -u M eth0
2.17 综合监控工具 glances
[root@rocky8 ~]# glances -bash: glances: command not found [root@rocky8 ~]# dnf -y install glances [root@rocky8 ~]# glances
此工具可以通过EPEL源安装,CentOS 8 目前已提供,但测试有问题
格式：
glances [-bdehmnrsvyz1] [-B bind] [-c server] [-C conffile] [-p port] [-P password] [--password] [-t refresh] [-f file] [-o output]
内建命令：
a Sort processes automatically l Show/hide logs c Sort processes by CPU% b Bytes or bits for network I/O m Sort processes by MEM% w Delete warning logs p Sort processes by name x Delete warning and critical logs i Sort processes by I/O rate 1 Global CPU or per-CPU stats d Show/hide disk I/O stats h Show/hide this help screen f Show/hide file system stats t View network I/O as combination n Show/hide network stats u View cumulative network I/O s Show/hide sensors stats q Quit (Esc and Ctrl-C also work) y Show/hide hddtemp stats
常用选项：
-b: 以Byte为单位显示网卡数据速率
-d: 关闭磁盘I/O模块
-f /path/to/somefile: 设定输入文件位置
-o {HTML|CSV}：输出格式
-m: 禁用mount模块
-n: 禁用网络模块
-t #: 延迟时间间隔
-1：每个CPU的相关数据单独显示
C/S模式下运行glances命令
- 服务器模式：
glances -s -B IPADDR IPADDR: 指明监听的本机哪个地址
- 客户端模式：
glances -c IPADDR IPADDR：要连入的服务器端地址
范例：
root@ubuntu1804:~# glances -s Glances XML-RPC server is running on 0.0.0.0:61209 root@ubuntu1804:~# ss -ntl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 127.0.0.53%lo:53 0.0.0.0:* LISTEN 0 128 0.0.0.0:22 0.0.0.0:* LISTEN 0 5 0.0.0.0:61209 0.0.0.0:* LISTEN 0 128 127.0.0.1:6010 0.0.0.0:* LISTEN 0 128 127.0.0.1:6011 0.0.0.0:* LISTEN 0 128 [::]:22 [::]:* LISTEN 0 128 [::1]:6010 [::]:* LISTEN 0 128 [::1]:6011 [::]:* root@ubuntu1804-2:~# glances -c 172.31.2.18
2.18 查看进程打开文件 lsof
lsof：list open files，查看当前系统文件的工具。在linux环境下，一切皆文件，用户通过文件不仅可以访问常规数据，还可以访问网络连接和硬件如传输控制协议 (TCP) 和用户数据报协议 (UDP)套接字等，系统在后台都为该应用程序分配了一个文件描述符
命令选项：
-a：列出打开文件存在的进程 -c<进程名>：列出指定进程所打开的文件 -g：列出GID号进程详情 -d<文件号>：列出占用该文件号的进程 +d<目录>：列出目录下被打开的文件 +D<目录>：递归列出目录下被打开的文件 -n<目录>：列出使用NFS的文件 -i<条件>：列出符合条件的进程(4、6、协议、:端口、 @ip ) -p<进程号>：列出指定进程号所打开的文件 -u：列出UID号进程详情 -h：显示帮助信息 -v：显示版本信息。 -n: 不反向解析网络名字
范例：
[root@rocky8 ~]# lsof
-bash: lsof: command not found
[root@rocky8 ~]# dnf -y install lsof
[root@rocky8 ~]# lsof |less
COMMAND PID TID TASKCMD USER FD TYPE DEVICE SIZE/OFF NODE NAME
systemd 1 root cwd DIR 8,2 256 128 /
systemd 1 root rtd DIR 8,2 256 128 /
systemd 1 root txt REG 8,2 1589040 484070 /usr/lib/systemd/systemd
systemd 1 root mem REG 8,2 147360 67167846 /usr/lib64/libnl-3.so.200.26.0
systemd 1 root mem REG 8,2 549872 67167854 /usr/lib64/libnl-route-3.so.200.26.0
systemd 1 root mem REG 8,2 131144 67543778 /usr/lib64/libibverbs.so.1.11.32.0
systemd 1 root mem REG 8,2 2191808 67117912 /usr/lib64/libm-2.28.so
systemd 1 root mem REG 8,2 633032 67556008 /usr/lib64/libudev.so.1.6.11
systemd 1 root mem REG 8,2 739264 67152232 /usr/lib64/libsepol.so.1
systemd 1 root mem REG 8,2 1580488 67167863 /usr/lib64/libunistring.so.2.1.0
systemd 1 root mem REG 8,2 312496 67543796 /usr/lib64/libpcap.so.1.9.1
systemd 1 root mem REG 8,2 138792 67152254 /usr/lib64/libgpg-error.so.0.24.2
systemd 1 root mem REG 8,2 66744 67167805 /usr/lib64/libjson-c.so.4.0.0
systemd 1 root mem REG 8,2 371208 67582024 /usr/lib64/libdevmapper.so.1.02
systemd 1 root mem REG 8,2 24784 67167807 /usr/lib64/libattr.so.1.1.2448
systemd 1 root mem REG 8,2 3071432 67582048 /usr/lib64/libcrypto.so.1.1.1g
systemd 1 root mem REG 8,2 615576 67582050 /usr/lib64/libssl.so.1.1.1g
systemd 1 root mem REG 8,2 95456 67152235 /usr/lib64/libz.so.1.2.11
systemd 1 root mem REG 8,2 25112 67167753 /usr/lib64/libcap-ng.so.0.0.0
systemd 1 root mem REG 8,2 33384 67152345 /usr/lib64/libuuid.so.1.3.0
systemd 1 root mem REG 8,2 28968 67117910 /usr/lib64/libdl-2.28.so
systemd 1 root mem REG 8,2 543152 67117790 /usr/lib64/libpcre2-8.so.0.7.1
systemd 1 root mem REG 8,2 343608 67556010 /usr/lib64/libblkid.so.1.1.0
systemd 1 root mem REG 8,2 119672 67188491 /usr/lib64/liblz4.so.1.8.3
systemd 1 root mem REG 8,2 162224 67152239 /usr/lib64/liblzma.so.5.2.4
[root@rocky8 ~]# lsof -i :22
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
sshd 765 root 4u IPv4 26729 0t0 TCP *:ssh (LISTEN)
sshd 765 root 6u IPv6 26740 0t0 TCP *:ssh (LISTEN)
sshd 10186 root 5u IPv4 72386 0t0 TCP rocky8:ssh->172.31.0.1:58670 (ESTABLISHED)
sshd 10188 root 5u IPv4 72386 0t0 TCP rocky8:ssh->172.31.0.1:58670 (ESTABLISHED)
sshd 10449 root 5u IPv4 73393 0t0 TCP rocky8:ssh->172.31.0.1:58954 (ESTABLISHED)
sshd 10451 root 5u IPv4 73393 0t0 TCP rocky8:ssh->172.31.0.1:58954 (ESTABLISHED)
sshd 10481 root 5u IPv4 73590 0t0 TCP rocky8:ssh->172.31.0.1:58955 (ESTABLISHED)
sshd 10483 root 5u IPv4 73590 0t0 TCP rocky8:ssh->172.31.0.1:58955 (ESTABLISHED)
[root@rocky8 ~]# tail -f /var/log/messages
Oct 31 18:29:24 rocky8 systemd[1]: Starting man-db-cache-update.service...
Oct 31 18:29:24 rocky8 systemd[1]: man-db-cache-update.service: Succeeded.
Oct 31 18:29:24 rocky8 systemd[1]: Started man-db-cache-update.service.
Oct 31 18:29:24 rocky8 systemd[1]: run-rf03d282b475c4d3bac2b755905b8b453.service: Succeeded.
Oct 31 18:48:07 rocky8 kernel: perf: interrupt took too long (6615 > 6601), lowering kernel.perf_event_max_sample_rate to 30000
Oct 31 18:58:00 rocky8 systemd[1]: Started /usr/bin/systemctl start man-db-cache-update.
Oct 31 18:58:00 rocky8 systemd[1]: Starting man-db-cache-update.service...
Oct 31 18:58:00 rocky8 systemd[1]: man-db-cache-update.service: Succeeded.
Oct 31 18:58:00 rocky8 systemd[1]: Started man-db-cache-update.service.
Oct 31 18:58:00 rocky8 systemd[1]: run-re58cc3ca0a874565bb0b1cf41e3cb739.service: Succeeded.
[root@rocky8 ~]# pstree -p |grep tail
|-sshd(765)-+-sshd(10186)---sshd(10188)---bash(10189)---tail(17292)
[root@rocky8 ~]# lsof -p 17292
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
tail 17292 root cwd DIR 8,2 251 201326721 /root
tail 17292 root rtd DIR 8,2 256 128 /
tail 17292 root txt REG 8,2 76120 423833 /usr/bin/tail
tail 17292 root mem REG 8,2 2586930 134352575 /usr/lib/locale/en_US.utf8/LC_COLLATE
tail 17292 root mem REG 8,2 3168120 67117908 /usr/lib64/libc-2.28.so
tail 17292 root mem REG 8,2 278432 67117901 /usr/lib64/ld-2.28.so
tail 17292 root mem REG 8,2 337024 134352640 /usr/lib/locale/en_US.utf8/LC_CTYPE
tail 17292 root mem REG 8,2 54 134352643 /usr/lib/locale/en_US.utf8/LC_NUMERIC
tail 17292 root mem REG 8,2 3316 201334461 /usr/lib/locale/en_US.utf8/LC_TIME
tail 17292 root mem REG 8,2 286 201334459 /usr/lib/locale/en_US.utf8/LC_MONETARY
tail 17292 root mem REG 8,2 57 201334471 /usr/lib/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES
tail 17292 root mem REG 8,2 34 67117882 /usr/lib/locale/en_US.utf8/LC_PAPER
tail 17292 root mem REG 8,2 77 134352642 /usr/lib/locale/en_US.utf8/LC_NAME
tail 17292 root mem REG 8,2 26998 67152228 /usr/lib64/gconv/gconv-modules.cache
tail 17292 root mem REG 8,2 167 201334456 /usr/lib/locale/en_US.utf8/LC_ADDRESS
tail 17292 root mem REG 8,2 59 201334460 /usr/lib/locale/en_US.utf8/LC_TELEPHONE
tail 17292 root mem REG 8,2 23 201334458 /usr/lib/locale/en_US.utf8/LC_MEASUREMENT
tail 17292 root mem REG 8,2 368 201334457 /usr/lib/locale/en_US.utf8/LC_IDENTIFICATION
tail 17292 root 0u CHR 136,2 0t0 5 /dev/pts/2
tail 17292 root 1u CHR 136,2 0t0 5 /dev/pts/2
tail 17292 root 2u CHR 136,2 0t0 5 /dev/pts/2
tail 17292 root 3r REG 8,2 619555 134724368 /var/log/messages
tail 17292 root 4r a_inode 0,14 0 10418 inotify
[root@rocky8 ~]# cat /proc/17292/fd/3
[root@rocky8 ~]# cat /proc/17292/fd/3 > /var/log/messages
[root@rocky8 ~]# ll /var/log/messages
-rw-------. 1 root root 0 Oct 31 19:04 /var/log/messages
范例：
#查看由登陆用户启动而非系统启动的进程 [root@rocky8 ~]# lsof /dev/pts/1 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME bash 10452 root 0u CHR 136,1 0t0 4 /dev/pts/1 bash 10452 root 1u CHR 136,1 0t0 4 /dev/pts/1 bash 10452 root 2u CHR 136,1 0t0 4 /dev/pts/1 bash 10452 root 255u CHR 136,1 0t0 4 /dev/pts/1 vim 10704 root 0u CHR 136,1 0t0 4 /dev/pts/1 vim 10704 root 1u CHR 136,1 0t0 4 /dev/pts/1 vim 10704 root 2u CHR 136,1 0t0 4 /dev/pts/1 #指定进程号，可以查看该进程打开的文件 [root@rocky8 ~]# lsof -p 22 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME kcompactd 22 root cwd DIR 8,2 256 128 / kcompactd 22 root rtd DIR 8,2 256 128 / kcompactd 22 root txt unknown /proc/22/exe [root@rocky8 ~]# bc bc 1.07.1 Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006, 2008, 2012-2017 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. [root@rocky8 ~]# lsof -p `pidof bc` COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME bc 17348 root cwd DIR 8,2 251 201326721 /root bc 17348 root rtd DIR 8,2 256 128 / bc 17348 root txt REG 8,2 92960 656596 /usr/bin/bc bc 17348 root mem REG 8,2 28968 67117910 /usr/lib64/libdl-2.28.so bc 17348 root mem REG 8,2 3168120 67117908 /usr/lib64/libc-2.28.so bc 17348 root mem REG 8,2 187472 67117821 /usr/lib64/libtinfo.so.6.1 bc 17348 root mem REG 8,2 180224 67117811 /usr/lib64/libncurses.so.6.1 bc 17348 root mem REG 8,2 324992 67152362 /usr/lib64/libreadline.so.7.0 bc 17348 root mem REG 8,2 278432 67117901 /usr/lib64/ld-2.28.so bc 17348 root mem REG 8,2 26998 67152228 /usr/lib64/gconv/gconv-modules.cache bc 17348 root mem REG 8,2 337024 134352640 /usr/lib/locale/en_US.utf8/LC_CTYPE bc 17348 root 0u CHR 136,3 0t0 6 /dev/pts/3 bc 17348 root 1u CHR 136,3 0t0 6 /dev/pts/3 bc 17348 root 2u CHR 136,3 0t0 6 /dev/pts/3 #查看指定程序打开的文件 [root@rocky8 ~]# lsof -c mysqld COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME mysqld 14755 mysql cwd DIR 8,2 4096 202180426 /var/lib/mysql mysqld 14755 mysql rtd DIR 8,2 256 128 / mysqld 14755 mysql txt REG 8,2 67443400 202180424 /usr/libexec/mysqld mysqld 14755 mysql DEL REG 0,18 93283 /[aio] mysqld 14755 mysql DEL REG 0,18 93282 /[aio] mysqld 14755 mysql DEL REG 0,18 93281 /[aio] mysqld 14755 mysql DEL REG 0,18 93280 /[aio] mysqld 14755 mysql DEL REG 0,18 93279 /[aio] mysqld 14755 mysql DEL REG 0,18 93278 /[aio] mysqld 14755 mysql DEL REG 0,18 93277 /[aio] mysqld 14755 mysql DEL REG 0,18 93276 /[aio] mysqld 14755 mysql DEL REG 0,18 93275 /[aio] mysqld 14755 mysql DEL REG 0,18 93274 /[aio] mysqld 14755 mysql DEL REG 0,18 93273 /[aio] mysqld 14755 mysql DEL REG 0,18 93272 /[aio] mysqld 14755 mysql mem REG 8,2 42872 68290771 /usr/lib64/mysql/plugin/component_reference_cache.so mysqld 14755 mysql mem REG 8,2 83656 67117920 /usr/lib64/libnss_files-2.28.so mysqld 14755 mysql mem REG 8,2 3168120 67117908 /usr/lib64/libc-2.28.so mysqld 14755 mysql mem REG 8,2 99656 67108999 /usr/lib64/libgcc_s-8-20200928.so.1 mysqld 14755 mysql mem REG 8,2 2191808 67117912 /usr/lib64/libm-2.28.so mysqld 14755 mysql mem REG 8,2 1661392 67152370 /usr/lib64/libstdc++.so.6.0.25 mysqld 14755 mysql mem REG 8,2 51656 67196504 /usr/lib64/libnuma.so.1.0.0 mysqld 14755 mysql mem REG 8,2 119672 67188491 /usr/lib64/liblz4.so.1.8.3 mysqld 14755 mysql mem REG 8,2 95456 67152235 /usr/lib64/libz.so.1.2.11 mysqld 14755 mysql mem REG 8,2 12264 68277612 /usr/lib64/libaio.so.1.0.1 mysqld 14755 mysql mem REG 8,2 28968 67117910 /usr/lib64/libdl-2.28.so mysqld 14755 mysql mem REG 8,2 3071432 67582048 /usr/lib64/libcrypto.so.1.1.1g mysqld 14755 mysql mem REG 8,2 615576 67582050 /usr/lib64/libssl.so.1.1.1g mysqld 14755 mysql mem REG 8,2 68944 67117926 /usr/lib64/librt-2.28.so mysqld 14755 mysql mem REG 8,2 460704 68256758 /usr/lib64/libprotobuf-lite.so.15.0.0 mysqld 14755 mysql mem REG 8,2 11640 67682224 /usr/lib64/libevent_pthreads-2.1.so.6.0.2 mysqld 14755 mysql mem REG 8,2 28560 67682222 /usr/lib64/libevent_openssl-2.1.so.6.0.2 mysqld 14755 mysql mem REG 8,2 149904 67682220 /usr/lib64/libevent_extra-2.1.so.6.0.2 mysqld 14755 mysql mem REG 8,2 236880 67682218 /usr/lib64/libevent_core-2.1.so.6.0.2 mysqld 14755 mysql mem REG 8,2 320504 67117922 /usr/lib64/libpthread-2.28.so mysqld 14755 mysql mem REG 8,2 278432 67117901 /usr/lib64/ld-2.28.so mysqld 14755 mysql 0r CHR 1,3 0t0 10424 /dev/null mysqld 14755 mysql 1w REG 8,2 1945 134800202 /var/log/mysql/mysqld.log mysqld 14755 mysql 2w REG 8,2 1945 134800202 /var/log/mysql/mysqld.log mysqld 14755 mysql 3u unix 0xffff988584e4cc80 0t0 90871 type=DGRAM mysqld 14755 mysql 4u REG 8,2 16 201878694 /var/lib/mysql/binlog.index mysqld 14755 mysql 5uW REG 8,2 50331648 201878660 /var/lib/mysql/ib_logfile0 mysqld 14755 mysql 6u REG 8,2 0 134651604 /var/tmp/#134651604 (deleted) mysqld 14755 mysql 7u REG 8,2 0 134651605 /var/tmp/#134651605 (deleted) mysqld 14755 mysql 8u REG 8,2 0 134651606 /var/tmp/#134651606 (deleted) mysqld 14755 mysql 9uW REG 8,2 12582912 201878659 /var/lib/mysql/ibdata1 mysqld 14755 mysql 10uW REG 8,2 50331648 201878661 /var/lib/mysql/ib_logfile1 mysqld 14755 mysql 11uW REG 8,2 196608 201878662 /var/lib/mysql/#ib_16384_0.dblwr mysqld 14755 mysql 12uW REG 8,2 8585216 201878663 /var/lib/mysql/#ib_16384_1.dblwr mysqld 14755 mysql 13uW REG 8,2 16777216 201878665 /var/lib/mysql/undo_001 mysqld 14755 mysql 14u REG 8,2 0 134651607 /var/tmp/#134651607 (deleted) mysqld 14755 mysql 15uW REG 8,2 16777216 201878667 /var/lib/mysql/undo_002 mysqld 14755 mysql 16uW REG 8,2 12582912 201878671 /var/lib/mysql/ibtmp1 mysqld 14755 mysql 17uW REG 8,2 28311552 201878664 /var/lib/mysql/mysql.ibd mysqld 14755 mysql 18u a_inode 0,14 0 10418 [eventpoll] mysqld 14755 mysql 19r FIFO 0,13 0t0 90874 pipe mysqld 14755 mysql 20w FIFO 0,13 0t0 90874 pipe mysqld 14755 mysql 21u a_inode 0,14 0 10418 [eventfd] mysqld 14755 mysql 22u IPv6 90876 0t0 TCP *:mysqlx (LISTEN) mysqld 14755 mysql 23u unix 0xffff988584e48000 0t0 90877 /var/lib/mysql/mysqlx.sock type=STREAM mysqld 14755 mysql 24uW REG 8,2 81920 201878689 /var/lib/mysql/#innodb_temp/temp_10.ibt mysqld 14755 mysql 25u IPv6 90879 0t0 TCP *:mysql (LISTEN) mysqld 14755 mysql 26w REG 8,2 156 201878693 /var/lib/mysql/binlog.000001 mysqld 14755 mysql 27u unix 0xffff988584e4e300 0t0 90880 /var/lib/mysql/mysql.sock type=STREAM mysqld 14755 mysql 28uW REG 8,2 81920 201878672 /var/lib/mysql/#innodb_temp/temp_1.ibt mysqld 14755 mysql 29uW REG 8,2 81920 201878673 /var/lib/mysql/#innodb_temp/temp_2.ibt mysqld 14755 mysql 30uW REG 8,2 81920 201878674 /var/lib/mysql/#innodb_temp/temp_3.ibt mysqld 14755 mysql 31uW REG 8,2 81920 201878675 /var/lib/mysql/#innodb_temp/temp_4.ibt mysqld 14755 mysql 32uW REG 8,2 81920 201878676 /var/lib/mysql/#innodb_temp/temp_5.ibt mysqld 14755 mysql 33uW REG 8,2 81920 201878677 /var/lib/mysql/#innodb_temp/temp_6.ibt mysqld 14755 mysql 34uW REG 8,2 81920 201878678 /var/lib/mysql/#innodb_temp/temp_7.ibt mysqld 14755 mysql 35uW REG 8,2 81920 201878679 /var/lib/mysql/#innodb_temp/temp_8.ibt mysqld 14755 mysql 36uW REG 8,2 81920 201878688 /var/lib/mysql/#innodb_temp/temp_9.ibt [root@rocky8 ~]# lsof -c bc COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME bc 17348 root cwd DIR 8,2 251 201326721 /root bc 17348 root rtd DIR 8,2 256 128 / bc 17348 root txt REG 8,2 92960 656596 /usr/bin/bc bc 17348 root mem REG 8,2 28968 67117910 /usr/lib64/libdl-2.28.so bc 17348 root mem REG 8,2 3168120 67117908 /usr/lib64/libc-2.28.so bc 17348 root mem REG 8,2 187472 67117821 /usr/lib64/libtinfo.so.6.1 bc 17348 root mem REG 8,2 180224 67117811 /usr/lib64/libncurses.so.6.1 bc 17348 root mem REG 8,2 324992 67152362 /usr/lib64/libreadline.so.7.0 bc 17348 root mem REG 8,2 278432 67117901 /usr/lib64/ld-2.28.so bc 17348 root mem REG 8,2 26998 67152228 /usr/lib64/gconv/gconv-modules.cache bc 17348 root mem REG 8,2 337024 134352640 /usr/lib/locale/en_US.utf8/LC_CTYPE bc 17348 root 0u CHR 136,3 0t0 6 /dev/pts/3 bc 17348 root 1u CHR 136,3 0t0 6 /dev/pts/3 bc 17348 root 2u CHR 136,3 0t0 6 /dev/pts/3 #查看指定用户打开的文件 [root@rocky8 ~]# lsof -u root |less COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME systemd 1 root cwd DIR 8,2 256 128 / systemd 1 root rtd DIR 8,2 256 128 / systemd 1 root txt REG 8,2 1589040 484070 /usr/lib/systemd/systemd systemd 1 root mem REG 8,2 147360 67167846 /usr/lib64/libnl-3.so.200.26.0 systemd 1 root mem REG 8,2 549872 67167854 /usr/lib64/libnl-route-3.so.200.26.0 systemd 1 root mem REG 8,2 131144 67543778 /usr/lib64/libibverbs.so.1.11.32.0 systemd 1 root mem REG 8,2 2191808 67117912 /usr/lib64/libm-2.28.so systemd 1 root mem REG 8,2 633032 67556008 /usr/lib64/libudev.so.1.6.11 systemd 1 root mem REG 8,2 739264 67152232 /usr/lib64/libsepol.so.1 systemd 1 root mem REG 8,2 1580488 67167863 /usr/lib64/libunistring.so.2.1.0 systemd 1 root mem REG 8,2 312496 67543796 /usr/lib64/libpcap.so.1.9.1 systemd 1 root mem REG 8,2 138792 67152254 /usr/lib64/libgpg-error.so.0.24.2 systemd 1 root mem REG 8,2 66744 67167805 /usr/lib64/libjson-c.so.4.0.0 systemd 1 root mem REG 8,2 371208 67582024 /usr/lib64/libdevmapper.so.1.02 systemd 1 root mem REG 8,2 24784 67167807 /usr/lib64/libattr.so.1.1.2448 systemd 1 root mem REG 8,2 3071432 67582048 /usr/lib64/libcrypto.so.1.1.1g systemd 1 root mem REG 8,2 615576 67582050 /usr/lib64/libssl.so.1.1.1g systemd 1 root mem REG 8,2 95456 67152235 /usr/lib64/libz.so.1.2.11 systemd 1 root mem REG 8,2 25112 67167753 /usr/lib64/libcap-ng.so.0.0.0 systemd 1 root mem REG 8,2 33384 67152345 /usr/lib64/libuuid.so.1.3.0 systemd 1 root mem REG 8,2 28968 67117910 /usr/lib64/libdl-2.28.so systemd 1 root mem REG 8,2 543152 67117790 /usr/lib64/libpcre2-8.so.0.7.1 systemd 1 root mem REG 8,2 343608 67556010 /usr/lib64/libblkid.so.1.1.0 systemd 1 root mem REG 8,2 119672 67188491 /usr/lib64/liblz4.so.1.8.3 systemd 1 root mem REG 8,2 162224 67152239 /usr/lib64/liblzma.so.5.2.4 #查看指定目录下被打开的文件，参数+D为递归列出目录下被打开的文件，参数+d为列出目录下被打开的文件 [root@rocky8 ~]# lsof +D /var/log/ COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME auditd 685 root 6w REG 8,2 526438 201929291 /var/log/audit/audit.log VGAuthSer 718 root 2w REG 8,2 6486 134328706 /var/log/vmware-vgauthsvc.log.0 VGAuthSer 718 root 4w REG 8,2 6486 134328706 /var/log/vmware-vgauthsvc.log.0 vmtoolsd 719 root 4w REG 8,2 7915 134328707 /var/log/vmware-vmsvc-root.log sssd 721 root 3w REG 8,2 3593 505665 /var/log/sssd/sssd.log tuned 767 root 4w REG 8,2 5609 67632835 /var/log/tuned/tuned.log sssd_be 773 root 6w REG 8,2 12023 505670 /var/log/sssd/sssd_implicit_files.log sssd_nss 809 root 6w REG 8,2 6488 505671 /var/log/sssd/sssd_nss.log rsyslogd 837 root 5w REG 8,2 7764 134724369 /var/log/secure rsyslogd 837 root 7w REG 8,2 0 134724368 /var/log/messages rsyslogd 837 root 8w REG 8,2 3676 134328713 /var/log/cron mysqld 14755 mysql 1w REG 8,2 1945 134800202 /var/log/mysql/mysqld.log mysqld 14755 mysql 2w REG 8,2 1945 134800202 /var/log/mysql/mysqld.log [root@rocky8 ~]# lsof +d /var/log/ COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME VGAuthSer 718 root 2w REG 8,2 6486 134328706 /var/log/vmware-vgauthsvc.log.0 VGAuthSer 718 root 4w REG 8,2 6486 134328706 /var/log/vmware-vgauthsvc.log.0 vmtoolsd 719 root 4w REG 8,2 7915 134328707 /var/log/vmware-vmsvc-root.log rsyslogd 837 root 5w REG 8,2 7764 134724369 /var/log/secure rsyslogd 837 root 7w REG 8,2 0 134724368 /var/log/messages rsyslogd 837 root 8w REG 8,2 3676 134328713 /var/log/cron #查看所有网络连接，通过参数-i查看网络连接的情况，包括连接的ip、端口等以及一些服务的连接情况，例如：sshd等。也可以通过指定ip查看该ip的网络连接情况 lsof -i –n lsof -i@127.0.0.1 #查看端口连接情况，通过参数-i:端口可以查看端口的占用情况，-i参数还有查看协议，ip的连接情况等 [root@rocky8 ~]# lsof -i :80 -n #查看指定进程打开的网络连接，参数-i、-a、-p等，-i查看网络连接情况，-a查看存在的进程，-p指定进程 lsof -i –n -a -p 9527 #查看指定状态的网络连接，-n:no host names, -P:no port names,-i TCP指定协议，-s指定协议状态通过多个参数可以清晰的查看网络连接情况、协议连接情况等 [root@rocky8 ~]# lsof -n -P -i TCP -s TCP:ESTABLISHED COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME sshd 10186 root 5u IPv4 72386 0t0 TCP 172.31.1.8:22->172.31.0.1:58670 (ESTABLISHED) sshd 10188 root 5u IPv4 72386 0t0 TCP 172.31.1.8:22->172.31.0.1:58670 (ESTABLISHED) sshd 10449 root 5u IPv4 73393 0t0 TCP 172.31.1.8:22->172.31.0.1:58954 (ESTABLISHED) sshd 10451 root 5u IPv4 73393 0t0 TCP 172.31.1.8:22->172.31.0.1:58954 (ESTABLISHED) sshd 10481 root 5u IPv4 73590 0t0 TCP 172.31.1.8:22->172.31.0.1:58955 (ESTABLISHED) sshd 10483 root 5u IPv4 73590 0t0 TCP 172.31.1.8:22->172.31.0.1:58955 (ESTABLISHED) sshd 17293 root 5u IPv4 176848 0t0 TCP 172.31.1.8:22->172.31.0.1:53960 (ESTABLISHED) sshd 17295 root 5u IPv4 176848 0t0 TCP 172.31.1.8:22->172.31.0.1:53960 (ESTABLISHED)
范例：利用 lsof 恢复正在使用中的误删除的文件
[root@rocky8 ~]# lsof |grep /var/log/messages rsyslogd 837 root 7w REG 8,2 0 134724368 /var/log/messages rsyslogd 837 850 in:imjour root 7w REG 8,2 0 134724368 /var/log/messages rsyslogd 837 852 rs:main root 7w REG 8,2 0 134724368 /var/log/messages [root@rocky8 ~]# rm -f /var/log/messages [root@rocky8 ~]# lsof |grep /var/log/messages rsyslogd 837 root 7w REG 8,2 0 134724368 /var/log/messages (deleted) rsyslogd 837 850 in:imjour root 7w REG 8,2 0 134724368 /var/log/messages (deleted) rsyslogd 837 852 rs:main root 7w REG 8,2 0 134724368 /var/log/messages (deleted) [root@rocky8 ~]# cat /proc/837/fd/8 [root@rocky8 ~]# cat /proc/837/fd/8 > /var/log/messages
2.19 CentOS 8 新特性 cockpit
Cockpit 是CentOS 8 取入的新特性，是一个基于 Web 界面的应用，它提供了对系统的图形化管理
- 监控系统活动（CPU、内存、磁盘 IO 和网络流量）
- 查看系统日志条目
- 查看磁盘分区的容量
- 查看网络活动（发送和接收）
- 查看用户帐户
- 检查系统服务的状态
- 提取已安装应用的信息
- 查看和安装可用更新（如果以 root 身份登录）并在需要时重新启动系统
- 打开并使用终端窗口
范例：安装 cockpit
[root@rocky8 ~]# dnf -y install cockpit;systemctl start cockpit [root@rocky8 ~]# ss -ntl State Recv-Q Send-Q Local Address:Port Peer Address:Port Process LISTEN 0 128 0.0.0.0:22 0.0.0.0:* LISTEN 0 128 *:9090 *:* LISTEN 0 70 *:33060 *:* LISTEN 0 128 *:3306 *:* LISTEN 0 128 [::]:22 [::]:*
打开浏览器，访问以下地址：
https://centos8主机:9090
2.20 信号发送 kill
kill：内部命令，可用来向进程发送控制信号，以实现对进程管理,每个信号对应一个数字，信号名称以SIG开头（可省略），不区分大小写
显示当前系统可用信号：
kill -l trap -l
查看帮助：man 7 signal
常用信号：
1) SIGHUP 无须关闭进程而让其重读配置文件 2) SIGINT 中止正在运行的进程；相当于Ctrl+c 3) SIGQUIT 相当于ctrl+\ 9) SIGKILL 强制杀死正在运行的进程,此信号慎用! 15) SIGTERM 终止正在运行的进程，默认信号 18) SIGCONT 继续运行 19) SIGSTOP 后台休眠,处于stop状态
指定信号的方法 :
- 信号的数字标识：1, 2, 9
- 信号完整名称：SIGHUP，sighup
- 信号的简写名称：HUP，hup
向进程发送信号：
按PID：
kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... or kill -l [sigspec]
范例：
kill -1 pid … kill -n 9 pid kill -s SIGINT pid
按名称：killall 来自于psmisc包
killall [-SIGNAL] comm…
按模式：
pkill [options] pattern
常用选项
-SIGNAL -u uid: effective user，生效者 -U uid: real user，真正发起运行命令者 -t terminal: 与指定终端相关的进程 -l: 显示进程名（pgrep可用） -a: 显示完整格式的进程名（pgrep可用） -P pid: 显示指定进程的子进程
范例：
[root@rocky8 ~]# kill -L
1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP
6) SIGABRT 7) SIGBUS 8) SIGFPE 9) SIGKILL 10) SIGUSR1
11) SIGSEGV 12) SIGUSR2 13) SIGPIPE 14) SIGALRM 15) SIGTERM
16) SIGSTKFLT 17) SIGCHLD 18) SIGCONT 19) SIGSTOP 20) SIGTSTP
21) SIGTTIN 22) SIGTTOU 23) SIGURG 24) SIGXCPU 25) SIGXFSZ
26) SIGVTALRM 27) SIGPROF 28) SIGWINCH 29) SIGIO 30) SIGPWR
31) SIGSYS 34) SIGRTMIN 35) SIGRTMIN+1 36) SIGRTMIN+2 37) SIGRTMIN+3
38) SIGRTMIN+4 39) SIGRTMIN+5 40) SIGRTMIN+6 41) SIGRTMIN+7 42) SIGRTMIN+8
43) SIGRTMIN+9 44) SIGRTMIN+10 45) SIGRTMIN+11 46) SIGRTMIN+12 47) SIGRTMIN+13
48) SIGRTMIN+14 49) SIGRTMIN+15 50) SIGRTMAX-14 51) SIGRTMAX-13 52) SIGRTMAX-12
53) SIGRTMAX-11 54) SIGRTMAX-10 55) SIGRTMAX-9 56) SIGRTMAX-8 57) SIGRTMAX-7
58) SIGRTMAX-6 59) SIGRTMAX-5 60) SIGRTMAX-4 61) SIGRTMAX-3 62) SIGRTMAX-2
63) SIGRTMAX-1 64) SIGRTMAX
[root@rocky8 ~]# ping 172.31.0.7
PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data.
64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.368 ms
64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.291 ms
...
[root@rocky8 ~]# kill `pidof ping` #默认就是-15 正常结束，可以不用写
[root@rocky8 ~]# ping 172.31.0.7
PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data.
64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.368 ms
64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.291 ms
64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=1.19 ms
64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.317 ms
64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.290 ms
64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.333 ms
64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.329 ms
64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=1.54 ms
64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.423 ms
64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.278 ms
64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.555 ms
64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=2.04 ms
64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.235 ms
64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=0.250 ms
64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=1.32 ms
64 bytes from 172.31.0.7: icmp_seq=16 ttl=64 time=0.302 ms
64 bytes from 172.31.0.7: icmp_seq=17 ttl=64 time=1.75 ms
64 bytes from 172.31.0.7: icmp_seq=18 ttl=64 time=0.303 ms
64 bytes from 172.31.0.7: icmp_seq=19 ttl=64 time=0.245 ms
64 bytes from 172.31.0.7: icmp_seq=20 ttl=64 time=2.40 ms
64 bytes from 172.31.0.7: icmp_seq=21 ttl=64 time=1.39 ms
64 bytes from 172.31.0.7: icmp_seq=22 ttl=64 time=0.187 ms
Terminated
[root@rocky8 ~]# pidof bash
17296 10770 10484 10452 10189
[root@rocky8 ~]# ps
PID TTY TIME CMD
10189 pts/2 00:00:00 bash
21327 pts/2 00:00:00 ps
[root@rocky8 ~]# kill 10189
#bash进程正常杀不了
[root@rocky8 ~]# kill -9 10189 #-9 强制杀掉进程
[root@rocky8 ~]# ping 172.31.0.7
PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data.
64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=1.21 ms
64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.325 ms
64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.224 ms
64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.257 ms
64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.184 ms
[root@rocky8 ~]# killall ping #killall 进程名 可以直接结束
[root@rocky8 ~]# ping 172.31.0.7
PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data.
64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=1.21 ms
64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.325 ms
64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.224 ms
64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.257 ms
64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.184 ms
64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.223 ms
64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.255 ms
64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=0.223 ms
64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.409 ms
64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.455 ms
64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.432 ms
64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=0.356 ms
64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.258 ms
64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=1.24 ms
64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=0.326 ms
64 bytes from 172.31.0.7: icmp_seq=16 ttl=64 time=0.396 ms
Terminated
范例：查看HUP信号
#许多服务的支持的reload操作，实际就是发送了HUP信号
#service httpd reload 即相当于 killall -1 httpd
[root@centos6 ~]# yum -y install httpd
[root@centos6 ~]# grep -A 10 -w reload -m 1 /etc/init.d/httpd
reload() {
echo -n $"Reloading $prog: "
if ! LANG=$HTTPD_LANG $httpd $OPTIONS -t >&/dev/null; then
RETVAL=6
echo $"not reloading due to configuration syntax error"
failure $"not reloading $httpd due to configuration syntax error"
else
# Force LSB behaviour from killproc
LSB=1 killproc -p ${pidfile} $httpd -HUP
RETVAL=$?
if [ $RETVAL -eq 7 ]; then
范例：利用 0 信号实现进程的健康性检查
[root@rocky8 ~]# man kill
If signal is 0, then no actual signal is sent, but error checking is still performed.
# kill -0 pid 不发送任何信号，但是系统会进行错误检查。
#所以经常用来检查一个进程是否存在，存在返回0；不存在返回1;
[root@rocky8 ~]# ping 172.31.0.7
PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data.
64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.269 ms
64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.526 ms
64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.288 ms
64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.624 ms
64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=1.13 ms
64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.216 ms
64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.709 ms
64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=0.583 ms
[root@rocky8 ~]# killall -0 ping #0不发送任何信号，但是会检查
[root@rocky8 ~]# echo $? #返回0 ,说明进程是健康的
0
[root@rocky8 ~]# killall ping
[root@rocky8 ~]# killall -0 ping
ping: no process found
[root@rocky8 ~]# echo $? #返回1，进程结束
1
#此方式有局限性，即使进程处于停止或僵尸状态，此方式仍然认为是进程是健康的
范例：
[root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.281 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=1.09 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.257 ms [root@rocky8 ~]# kill -s SIGKILL `pidof ping` [root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.281 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=1.09 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.257 ms 64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.222 ms 64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.277 ms 64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.473 ms 64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.340 ms 64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=0.337 ms 64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.578 ms 64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.567 ms 64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.391 ms 64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=0.215 ms 64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.603 ms 64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=0.243 ms 64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=0.218 ms 64 bytes from 172.31.0.7: icmp_seq=16 ttl=64 time=0.350 ms 64 bytes from 172.31.0.7: icmp_seq=17 ttl=64 time=0.562 ms 64 bytes from 172.31.0.7: icmp_seq=18 ttl=64 time=0.763 ms 64 bytes from 172.31.0.7: icmp_seq=19 ttl=64 time=0.412 ms 64 bytes from 172.31.0.7: icmp_seq=20 ttl=64 time=0.521 ms Killed [root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.266 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.443 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.397 ms [root@rocky8 ~]# kill -SIGKILL `pidof ping` [root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.266 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.443 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.397 ms 64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.545 ms 64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.819 ms 64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.231 ms 64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.306 ms 64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=0.248 ms 64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.205 ms 64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.232 ms 64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.470 ms 64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=0.554 ms 64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.262 ms 64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=0.382 ms 64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=0.499 ms 64 bytes from 172.31.0.7: icmp_seq=16 ttl=64 time=0.189 ms 64 bytes from 172.31.0.7: icmp_seq=17 ttl=64 time=0.245 ms 64 bytes from 172.31.0.7: icmp_seq=18 ttl=64 time=0.490 ms 64 bytes from 172.31.0.7: icmp_seq=19 ttl=64 time=0.534 ms 64 bytes from 172.31.0.7: icmp_seq=20 ttl=64 time=0.242 ms Killed [root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.284 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.188 ms [root@rocky8 ~]# kill -KILL `pidof ping` [root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.284 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.188 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.271 ms 64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.186 ms 64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.238 ms 64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.211 ms 64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.326 ms 64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=0.348 ms 64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.498 ms 64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.363 ms 64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.430 ms 64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=0.300 ms 64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.222 ms 64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=0.278 ms 64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=0.797 ms 64 bytes from 172.31.0.7: icmp_seq=16 ttl=64 time=0.355 ms Killed [root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.433 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.499 ms [root@rocky8 ~]# kill -9 `pidof ping` [root@rocky8 ~]# ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.433 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.499 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.386 ms 64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.307 ms 64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.246 ms 64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.584 ms 64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.332 ms 64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=1.04 ms 64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.220 ms 64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.448 ms 64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.218 ms 64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=0.278 ms 64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.387 ms 64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=0.539 ms 64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=0.377 ms Killed [root@rocky8 ~]# su - raymond Last login: Sun Oct 31 16:49:34 CST 2021 on pts/0 [raymond@rocky8 ~]$ ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.292 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.245 ms [root@rocky8 ~]# pkill -u raymond [raymond@rocky8 ~]$ ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.292 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.245 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.801 ms 64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.243 ms 64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.214 ms 64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.220 ms 64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.262 ms 64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=0.259 ms 64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.432 ms 64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.476 ms 64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.201 ms 64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=0.419 ms 64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.514 ms 64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=0.265 ms 64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=0.292 ms 64 bytes from 172.31.0.7: icmp_seq=16 ttl=64 time=0.416 ms 64 bytes from 172.31.0.7: icmp_seq=17 ttl=64 time=0.298 ms 64 bytes from 172.31.0.7: icmp_seq=18 ttl=64 time=0.230 ms 64 bytes from 172.31.0.7: icmp_seq=19 ttl=64 time=0.417 ms 64 bytes from 172.31.0.7: icmp_seq=20 ttl=64 time=0.230 ms 64 bytes from 172.31.0.7: icmp_seq=21 ttl=64 time=0.217 ms Terminated [raymond@rocky8 ~]$ ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.340 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.265 ms [root@rocky8 ~]# pkill -u -9 raymond [raymond@rocky8 ~]$ ping 172.31.0.7 PING 172.31.0.7 (172.31.0.7) 56(84) bytes of data. 64 bytes from 172.31.0.7: icmp_seq=1 ttl=64 time=0.340 ms 64 bytes from 172.31.0.7: icmp_seq=2 ttl=64 time=0.265 ms 64 bytes from 172.31.0.7: icmp_seq=3 ttl=64 time=0.450 ms 64 bytes from 172.31.0.7: icmp_seq=4 ttl=64 time=0.228 ms 64 bytes from 172.31.0.7: icmp_seq=5 ttl=64 time=0.595 ms 64 bytes from 172.31.0.7: icmp_seq=6 ttl=64 time=0.551 ms 64 bytes from 172.31.0.7: icmp_seq=7 ttl=64 time=0.242 ms 64 bytes from 172.31.0.7: icmp_seq=8 ttl=64 time=0.368 ms 64 bytes from 172.31.0.7: icmp_seq=9 ttl=64 time=0.276 ms 64 bytes from 172.31.0.7: icmp_seq=10 ttl=64 time=0.551 ms 64 bytes from 172.31.0.7: icmp_seq=11 ttl=64 time=0.230 ms 64 bytes from 172.31.0.7: icmp_seq=12 ttl=64 time=0.697 ms 64 bytes from 172.31.0.7: icmp_seq=13 ttl=64 time=0.538 ms 64 bytes from 172.31.0.7: icmp_seq=14 ttl=64 time=0.485 ms 64 bytes from 172.31.0.7: icmp_seq=15 ttl=64 time=0.739 ms 64 bytes from 172.31.0.7: icmp_seq=16 ttl=64 time=0.460 ms 64 bytes from 172.31.0.7: icmp_seq=17 ttl=64 time=0.516 ms 64 bytes from 172.31.0.7: icmp_seq=18 ttl=64 time=0.395 ms 64 bytes from 172.31.0.7: icmp_seq=19 ttl=64 time=0.216 ms Killed
2.21 作业管理
Linux的作业控制
-
前台作业：通过终端启动，且启动后一直占据终端
-
后台作业：可通过终端启动，但启动后即转入后台运行（释放终端）
让作业运行于后台 -
运行中的作业： Ctrl+z
-
尚未启动的作业： COMMAND &
后台作业虽然被送往后台运行，但其依然与终端相关；退出终端，将关闭后台作业。如果希望送往后台后，剥离与终端的关系
- nohup COMMAND &>/dev/null &
- screen；COMMAND
- tmux；COMMAND
查看当前终端所有作业：
jobs
作业控制：
fg [[%]JOB_NUM]：把指定的后台作业调回前台 bg [[%]JOB_NUM]：让送往后台的作业在后台继续运行 kill [%JOB_NUM]： 终止指定的作业
范例：
[root@rocky8 ~]# ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.023 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.026 ms
^C
--- 127.0.0.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1021ms
rtt min/avg/max/mdev = 0.023/0.024/0.026/0.005 ms
[root@rocky8 ~]# ping 127.0.0.1&
[1] 22545
[root@rocky8 ~]# PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.017 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.027 ms
64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.040 ms
64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.040 ms
64 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time=0.046 ms
64 bytes from 127.0.0.1: icmp_seq=6 ttl=64 time=0.047 ms
#关掉窗口
[root@rocky8 ~]# pstree -p |grep ping
|-ping(22487)
[root@rocky8 ~]# ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.021 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.029 ms
^Z
[1]+ Stopped ping 127.0.0.1 #ctrl+z 后台停止
[root@rocky8 ~]# ps aux |grep ping
root 22487 0.0 0.2 32448 2304 ? S 20:00 0:00 ping 127.0.0.1
root 22607 0.0 0.3 32448 2492 pts/0 T 20:04 0:00 ping 127.0.0.1
root 22609 0.0 0.1 12136 1152 pts/0 S+ 20:04 0:00 grep --color=auto ping
[root@rocky8 ~]# jobs
[1]+ Stopped ping 127.0.0.1
[root@rocky8 ~]# ping 127.2 &
[2] 4274
[root@rocky8 ~]# PING 127.2 (127.0.0.2) 56(84) bytes of data.
64 bytes from 127.0.0.2: icmp_seq=1 ttl=64 time=0.017 ms
64 bytes from 127.0.0.2: icmp_seq=2 ttl=64 time=0.049 ms
jo64 bytes from 127.0.0.2: icmp_seq=3 ttl=64 time=0.046 ms
bs64 bytes from 127.0.0.2: icmp_seq=4 ttl=64 time=0.051 ms
64 bytes from 127.0.0.2: icmp_seq=5 ttl=64 time=0.046 ms
[1]+ Stopped ping 127.0.0.1
[2]- Running ping 127.2 &
[root@rocky8 ~]# kill -19 %2 #把后台运行的程序变成后台停止
[root@rocky8 ~]# jobs
[1]- Stopped ping 127.0.0.1
[2]+ Stopped ping 127.2
[root@rocky8 ~]# bg 1 #把作业编号1,从停止态变成运行态
[1]- ping 127.0.0.1 &
[root@rocky8 ~]# 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.023 ms
64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.027 ms
64 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time=0.027 ms
kill -18 %2 #把作业编号2,从停止态变成运行态
fg %1 #把作业编号1，从后台变成前台
fg %2 #把作业编号2，从后台变成前台
2.22 并行运行
利用后台执行，实现并行功能，即同时运行多个进程，提高效率
方法1
cat all.sh f1.sh& f2.sh& f3.sh&
方法2
(f1.sh&);(f2.sh&);(f3.sh&)
方法3
f1.sh&f2.sh&f3.sh&
范例：多组命令实现并行
[root@rocky8 ~]# { ping -c3 127.1; ping 127.2; }& { ping -c3 127.3 ;ping 127.4; }&
范例：
[root@rocky8 ~]# vim check_host.sh
#!/bin/bash
#
#**********************************************************************************************
#Author: Raymond
#QQ: 88563128
#Date: 2021-10-31
#FileName: check_host.sh
#URL: raymond.blog.csdn.net
#Description: The test script
#Copyright (C): 2021 All rights reserved
#*********************************************************************************************
net=172.31.0
for i in {1..254};do
{ ping -c1 -w1 $net.$i &>/dev/null && echo $net.$i is up | tee -a hostlist.log || echo $net.$i is down;}&
done
wait
[root@rocky8 ~]# bash check_host.sh
172.31.0.6 is up
172.31.0.7 is up
172.31.0.2 is up
172.31.0.4 is down
172.31.0.8 is down
172.31.0.1 is down
172.31.0.14 is down
172.31.0.16 is down
172.31.0.39 is down
172.31.0.33 is down
172.31.0.29 is down
172.31.0.42 is down
172.31.0.22 is down
172.31.0.18 is down
172.31.0.31 is down
172.31.0.24 is down
172.31.0.20 is down
172.31.0.27 is down
172.31.0.35 is down
172.31.0.37 is down
172.31.0.44 is down
172.31.0.47 is down
172.31.0.50 is down
172.31.0.10 is down
172.31.0.57 is down
172.31.0.67 is down
172.31.0.62 is down
172.31.0.3 is down
172.31.0.19 is down
172.31.0.28 is down
172.31.0.64 is down
172.31.0.73 is down
172.31.0.93 is down
172.31.0.12 is down
172.31.0.15 is down
172.31.0.84 is down
172.31.0.45 is down
172.31.0.86 is down
172.31.0.36 is down
172.31.0.32 is down
172.31.0.21 is down
172.31.0.69 is down
172.31.0.78 is down
172.31.0.25 is down
172.31.0.114 is down
172.31.0.123 is down
172.31.0.209 is down
172.31.0.179 is down
172.31.0.222 is down
172.31.0.206 is down
172.31.0.88 is down
172.31.0.150 is down
172.31.0.98 is down
172.31.0.249 is down
172.31.0.251 is down
172.31.0.149 is down
172.31.0.168 is down
172.31.0.99 is down
172.31.0.115 is down
172.31.0.96 is down
172.31.0.243 is down
172.31.0.177 is down
172.31.0.159 is down
172.31.0.241 is down
172.31.0.140 is down
172.31.0.90 is down
172.31.0.205 is down
172.31.0.130 is down
172.31.0.40 is down
172.31.0.246 is down
172.31.0.54 is down
172.31.0.122 is down
172.31.0.11 is down
172.31.0.58 is down
172.31.0.70 is down
172.31.0.139 is down
172.31.0.156 is down
172.31.0.80 is down
172.31.0.52 is down
172.31.0.81 is down
172.31.0.49 is down
172.31.0.60 is down
172.31.0.59 is down
172.31.0.121 is down
172.31.0.181 is down
172.31.0.74 is down
172.31.0.66 is down
172.31.0.83 is down
172.31.0.195 is down
172.31.0.23 is down
172.31.0.161 is down
172.31.0.65 is down
172.31.0.17 is down
172.31.0.153 is down
172.31.0.75 is down
172.31.0.79 is down
172.31.0.132 is down
172.31.0.104 is down
172.31.0.53 is down
172.31.0.190 is down
172.31.0.211 is down
172.31.0.134 is down
172.31.0.217 is down
172.31.0.240 is down
172.31.0.148 is down
172.31.0.55 is down
172.31.0.238 is down
172.31.0.165 is down
172.31.0.63 is down
172.31.0.210 is down
172.31.0.171 is down
172.31.0.248 is down
172.31.0.189 is down
172.31.0.250 is down
172.31.0.127 is down
172.31.0.43 is down
172.31.0.136 is down
172.31.0.105 is down
172.31.0.82 is down
172.31.0.203 is down
172.31.0.116 is down
172.31.0.107 is down
172.31.0.71 is down
172.31.0.131 is down
172.31.0.175 is down
172.31.0.141 is down
172.31.0.77 is down
172.31.0.125 is down
172.31.0.48 is down
172.31.0.146 is down
172.31.0.110 is down
172.31.0.109 is down
172.31.0.223 is down
172.31.0.184 is down
172.31.0.225 is down
172.31.0.200 is down
172.31.0.183 is down
172.31.0.97 is down
172.31.0.234 is down
172.31.0.144 is down
172.31.0.187 is down
172.31.0.226 is down
172.31.0.182 is down
172.31.0.152 is down
172.31.0.145 is down
172.31.0.85 is down
172.31.0.129 is down
172.31.0.120 is down
172.31.0.178 is down
172.31.0.253 is down
172.31.0.103 is down
172.31.0.202 is down
172.31.0.143 is down
172.31.0.138 is down
172.31.0.185 is down
172.31.0.244 is down
172.31.0.68 is down
172.31.0.111 is down
172.31.0.89 is down
172.31.0.215 is down
172.31.0.163 is down
172.31.0.214 is down
172.31.0.119 is down
172.31.0.213 is down
172.31.0.218 is down
172.31.0.128 is down
172.31.0.30 is down
172.31.0.135 is down
172.31.0.72 is down
172.31.0.26 is down
172.31.0.193 is down
172.31.0.94 is down
172.31.0.194 is down
172.31.0.51 is down
172.31.0.38 is down
172.31.0.87 is down
172.31.0.221 is down
172.31.0.34 is down
172.31.0.108 is down
172.31.0.76 is down
172.31.0.56 is down
172.31.0.92 is down
172.31.0.224 is down
172.31.0.46 is down
172.31.0.91 is down
172.31.0.157 is down
172.31.0.41 is down
172.31.0.188 is down
172.31.0.61 is down
172.31.0.254 is down
172.31.0.112 is down
172.31.0.169 is down
172.31.0.237 is down
172.31.0.160 is down
172.31.0.173 is down
172.31.0.158 is down
172.31.0.154 is down
172.31.0.176 is down
172.31.0.106 is down
172.31.0.118 is down
172.31.0.230 is down
172.31.0.229 is down
172.31.0.167 is down
172.31.0.100 is down
172.31.0.95 is down
172.31.0.232 is down
172.31.0.172 is down
172.31.0.245 is down
172.31.0.133 is down
172.31.0.137 is down
172.31.0.170 is down
172.31.0.191 is down
172.31.0.113 is down
172.31.0.126 is down
172.31.0.252 is down
172.31.0.174 is down
172.31.0.235 is down
172.31.0.212 is down
172.31.0.247 is down
172.31.0.242 is down
172.31.0.192 is down
172.31.0.228 is down
172.31.0.204 is down
172.31.0.151 is down
172.31.0.216 is down
172.31.0.236 is down
172.31.0.101 is down
172.31.0.231 is down
172.31.0.199 is down
172.31.0.233 is down
172.31.0.208 is down
172.31.0.207 is down
172.31.0.220 is down
172.31.0.239 is down
172.31.0.124 is down
172.31.0.13 is down
172.31.0.180 is down
172.31.0.227 is down
172.31.0.186 is down
172.31.0.5 is down
172.31.0.198 is down
172.31.0.162 is down
172.31.0.219 is down
172.31.0.117 is down
172.31.0.147 is down
172.31.0.155 is down
172.31.0.102 is down
172.31.0.197 is down
172.31.0.142 is down
172.31.0.166 is down
172.31.0.9 is down
172.31.0.196 is down
172.31.0.201 is down
172.31.0.164 is down
[root@rocky8 ~]# cat hostlist.log
172.31.0.6 is up
172.31.0.7 is up
172.31.0.2 is up
3.任务计划
通过任务计划，可以让系统自动的按时间或周期性任务执行任务
未来的某时间点执行一次任务
- at 指定时间点，执行一次性任务
- batch 系统自行选择空闲时间去执行此处指定的任务
周期性运行某任务
- cron
3.1 一次性任务
at 工具
- 由包 at 提供
- 依赖与atd服务,需要启动才能实现at任务
- at队列存放在/var/spool/at目录中,ubuntu存放在/var/spool/cron/atjobs目录下
- 执行任务时PATH变量的值和当前定义任务的用户身份一致
at 命令：
at [option] TIME
常用选项：
-V 显示版本信息 -t time 时间格式 [[CC]YY]MMDDhhmm[.ss] -l 列出指定队列中等待运行的作业；相当于atq -d N 删除指定的N号作业；相当于atrm -c N 查看具体作业N号任务 -f file 指定的文件中读取任务 -m 当任务被完成之后，将给用户发送邮件，即使没有标准输出
注意：
作业执行命令的结果中的标准输出和错误以执行任务的用户身份发邮件通知给 root
默认CentOS 8 最小化安装没有安装邮件服务,需要自行安装
范例:
[root@rocky8 ~]# dnf install postfix -y;systemctl enable --now postfix
TIME：定义出什么时候进行 at 这项任务的时间
HH:MM [YYYY-mm-dd]
noon, midnight, teatime（4pm）
tomorrow
now+#{minutes,hours,days, OR weeks}
范例：at 时间格式
HH:MM 在今日的 HH:MM 进行，若该时刻已过，则明天此时执行任务 02:00 HH:MM YYYY-MM-DD 规定在某年某月的某一天的特殊时刻进行该项任务 02:00 2016-09-20 HH:MM[am|pm] [Month] [Date] 06pm March 17 17:20 tomorrow HH:MM[am|pm] + number [minutes|hours|days|weeks]， 在某个时间点再加几个时间后才进行该项任务 now + 5 min 02pm + 3 days
at 任务执行方式：
- 交互式
- 输入重定向
- at -f file
/etc/at.{allow,deny} 控制用户是否能执行at任务
- 白名单：/etc/at.allow 默认不存在，只有该文件中的用户才能执行at命令
- 黑名单：/etc/at.deny 默认存在，拒绝该文件中用户执行at命令，而没有在at.deny 文件中的使用者则可执行
- 如果两个文件都不存在，只有 root 可以执行 at 命令
范例:
[root@rocky8 ~]# at
-bash: at: command not found
[root@rocky8 ~]# dnf provides at
Last metadata expiration check: 2:51:45 ago on Sun 31 Oct 2021 05:56:28 PM CST.
at-3.1.20-11.el8.x86_64 : Job spooling tools
Repo : BaseOS
Matched from:
Provide : at = 3.1.20-11.el8
[root@rocky8 ~]# dnf -y install at
[root@rocky8 ~]# at
Garbled time
[root@rocky8 ~]# systemctl status atd
● atd.service - Job spooling tools
Loaded: loaded (/usr/lib/systemd/system/atd.service; enabled; vendor preset: enabled)
Active: inactive (dead)
[root@rocky8 ~]# systemctl enable --now atd
[root@rocky8 ~]# systemctl status atd
● atd.service - Job spooling tools
Loaded: loaded (/usr/lib/systemd/system/atd.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2021-10-31 20:49:10 CST; 1s ago
Main PID: 26480 (atd)
Tasks: 1 (limit: 4783)
Memory: 364.0K
CGroup: /system.slice/atd.service
└─26480 /usr/sbin/atd -f
Oct 31 20:49:10 rocky8 systemd[1]: Started Job spooling tools.
[root@rocky8 ~]# rpm -ql at
/etc/at.deny
/etc/pam.d/atd
/etc/sysconfig/atd
/usr/bin/at
/usr/bin/atq
/usr/bin/atrm
/usr/bin/batch
/usr/lib/.build-id
/usr/lib/.build-id/02
/usr/lib/.build-id/02/0647ed6e6ce8fe84e8aac1d6897b5c786af578
/usr/lib/.build-id/d3
/usr/lib/.build-id/d3/c5d5906a6757aec0f1f97ead0c4638d927f33b
/usr/lib/systemd/system/atd.service
/usr/sbin/atd
/usr/sbin/atrun
/usr/share/doc/at
/usr/share/doc/at/ChangeLog
/usr/share/doc/at/README
/usr/share/doc/at/timespec
/usr/share/licenses/at
/usr/share/licenses/at/COPYING
/usr/share/licenses/at/Copyright
/usr/share/man/man1/at.1.gz
/usr/share/man/man1/atq.1.gz
/usr/share/man/man1/atrm.1.gz
/usr/share/man/man1/batch.1.gz
/usr/share/man/man5/at.allow.5.gz
/usr/share/man/man5/at.deny.5.gz
/usr/share/man/man8/atd.8.gz
/usr/share/man/man8/atrun.8.gz
/var/spool/at
/var/spool/at/.SEQ
/var/spool/at/spool
[root@rocky8 ~]# at -h
Usage: at [-V] [-q x] [-f file] [-mMlbv] timespec ...
at [-V] [-q x] [-f file] [-mMlbv] -t time
at -c job ...
atq [-V] [-q x]
at [ -rd ] job ...
atrm [-V] job ...
batch
[root@rocky8 ~]# dnf -y install postfix
[root@rocky8 ~]# systemctl enable --now postfix
[root@rocky8 ~]# systemctl status postfix
● postfix.service - Postfix Mail Transport Agent
Loaded: loaded (/usr/lib/systemd/system/postfix.service; enabled; vendor preset: disabled)
Active: active (running) since Mon 2021-11-01 15:32:09 CST; 1s ago
Process: 10605 ExecStart=/usr/sbin/postfix start (code=exited, status=0/SUCCESS)
Process: 10603 ExecStartPre=/usr/libexec/postfix/chroot-update (code=exited, status=0/SUCCESS)
Process: 10599 ExecStartPre=/usr/libexec/postfix/aliasesdb (code=exited, status=0/SUCCESS)
Main PID: 10674 (master)
Tasks: 3 (limit: 4783)
Memory: 5.0M
CGroup: /system.slice/postfix.service
├─10674 /usr/libexec/postfix/master -w
├─10675 pickup -l -t unix -u
└─10676 qmgr -l -t unix -u
Nov 01 15:32:08 rocky8 systemd[1]: Starting Postfix Mail Transport Agent...
Nov 01 15:32:09 rocky8 postfix/master[10674]: daemon started -- version 3.5.8, configuration /etc/postfix
Nov 01 15:32:09 rocky8 systemd[1]: Started Postfix Mail Transport Agent.
[root@rocky8 ~]# mail
-bash: mail: command not found
[root@rocky8 ~]# dnf provides mail
Last metadata expiration check: 0:04:03 ago on Mon 01 Nov 2021 03:29:21 PM CST.
mailx-12.5-29.el8.x86_64 : Enhanced implementation of the mailx command
Repo : BaseOS
Matched from:
Filename : /bin/mail
[root@rocky8 ~]# dnf -y install mailx
[root@rocky8 ~]# ss -ntl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 100 127.0.0.1:25 0.0.0.0:*
LISTEN 0 128 *:9090 *:*
LISTEN 0 70 *:33060 *:*
LISTEN 0 128 *:3306 *:*
LISTEN 0 128 [::]:22 [::]:*
LISTEN 0 100 [::1]:25 [::]:*
[root@rocky8 ~]# at 16:00
warning: commands will be executed using /bin/sh
at> touch /data/a.txt
at> <EOT>
job 1 at Mon Nov 1 16:00:00 2021
#ctrl+d 保存计划任务
[root@rocky8 ~]# at -l #at -l 查看计划任务
1 Mon Nov 1 16:00:00 2021 a root
[root@rocky8 ~]# at -c 1 #at -c 作业编号 查看计划任务
#!/bin/sh
# atrun uid=0 gid=0
# mail root 0
umask 22
LS_COLORS=rs=0:di=01\;34:ln=01\;36:mh=00:pi=40\;33:so=01\;35:do=01\;35:bd=40\;33\;01:cd=40\;33\;01:or=40\;31\;01:mi=01\;05\;37\;41:su=37\;41:sg=30\;43:ca=30\;41:tw=30\;42:ow=34\;42:st=37\;44:ex=01\;32:\*.tar=01\;31:\*.tgz=01\;31:\*.arc=01\;31:\*.arj=01\;31:\*.taz=01\;31:\*.lha=01\;31:\*.lz4=01\;31:\*.lzh=01\;31:\*.lzma=01\;31:\*.tlz=01\;31:\*.txz=01\;31:\*.tzo=01\;31:\*.t7z=01\;31:\*.zip=01\;31:\*.z=01\;31:\*.dz=01\;31:\*.gz=01\;31:\*.lrz=01\;31:\*.lz=01\;31:\*.lzo=01\;31:\*.xz=01\;31:\*.zst=01\;31:\*.tzst=01\;31:\*.bz2=01\;31:\*.bz=01\;31:\*.tbz=01\;31:\*.tbz2=01\;31:\*.tz=01\;31:\*.deb=01\;31:\*.rpm=01\;31:\*.jar=01\;31:\*.war=01\;31:\*.ear=01\;31:\*.sar=01\;31:\*.rar=01\;31:\*.alz=01\;31:\*.ace=01\;31:\*.zoo=01\;31:\*.cpio=01\;31:\*.7z=01\;31:\*.rz=01\;31:\*.cab=01\;31:\*.wim=01\;31:\*.swm=01\;31:\*.dwm=01\;31:\*.esd=01\;31:\*.jpg=01\;35:\*.jpeg=01\;35:\*.mjpg=01\;35:\*.mjpeg=01\;35:\*.gif=01\;35:\*.bmp=01\;35:\*.pbm=01\;35:\*.pgm=01\;35:\*.ppm=01\;35:\*.tga=01\;35:\*.xbm=01\;35:\*.xpm=01\;35:\*.tif=01\;35:\*.tiff=01\;35:\*.png=01\;35:\*.svg=01\;35:\*.svgz=01\;35:\*.mng=01\;35:\*.pcx=01\;35:\*.mov=01\;35:\*.mpg=01\;35:\*.mpeg=01\;35:\*.m2v=01\;35:\*.mkv=01\;35:\*.webm=01\;35:\*.ogm=01\;35:\*.mp4=01\;35:\*.m4v=01\;35:\*.mp4v=01\;35:\*.vob=01\;35:\*.qt=01\;35:\*.nuv=01\;35:\*.wmv=01\;35:\*.asf=01\;35:\*.rm=01\;35:\*.rmvb=01\;35:\*.flc=01\;35:\*.avi=01\;35:\*.fli=01\;35:\*.flv=01\;35:\*.gl=01\;35:\*.dl=01\;35:\*.xcf=01\;35:\*.xwd=01\;35:\*.yuv=01\;35:\*.cgm=01\;35:\*.emf=01\;35:\*.ogv=01\;35:\*.ogx=01\;35:\*.aac=01\;36:\*.au=01\;36:\*.flac=01\;36:\*.m4a=01\;36:\*.mid=01\;36:\*.midi=01\;36:\*.mka=01\;36:\*.mp3=01\;36:\*.mpc=01\;36:\*.ogg=01\;36:\*.ra=01\;36:\*.wav=01\;36:\*.oga=01\;36:\*.opus=01\;36:\*.spx=01\;36:\*.xspf=01\;36:; export LS_COLORS
SSH_CONNECTION=172.31.0.1\ 53218\ 172.31.1.8\ 22; export SSH_CONNECTION
LANG=en_US.UTF-8; export LANG
HISTCONTROL=ignoredups; export HISTCONTROL
HISTTIMEFORMAT=%F\ %T\ ; export HISTTIMEFORMAT
HOSTNAME=rocky8; export HOSTNAME
EDITOR=vim; export EDITOR
XDG_SESSION_ID=1; export XDG_SESSION_ID
USER=root; export USER
PWD=/root; export PWD
HOME=/root; export HOME
SSH_CLIENT=172.31.0.1\ 53218\ 22; export SSH_CLIENT
SSH_TTY=/dev/pts/0; export SSH_TTY
MAIL=/var/spool/mail/root; export MAIL
SHELL=/bin/bash; export SHELL
SHLVL=1; export SHLVL
LOGNAME=root; export LOGNAME
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/0/bus; export DBUS_SESSION_BUS_ADDRESS
XDG_RUNTIME_DIR=/run/user/0; export XDG_RUNTIME_DIR
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin; export PATH
HISTSIZE=1000; export HISTSIZE
LESSOPEN=\|\|/usr/bin/lesspipe.sh\ %s; export LESSOPEN
cd /root || {
echo 'Execution directory inaccessible' >&2
exit 1
}
${SHELL:-/bin/sh} << 'marcinDELIMITER169bcccc'
touch /data/a.txt
marcinDELIMITER169bcccc
[root@rocky8 ~]# ls /data/a.txt
/data/a.txt
[root@rocky8 ~]# stat /data/a.txt
File: /data/a.txt
Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: 803h/2051d Inode: 131 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2021-11-01 16:00:00.030963124 +0800
Modify: 2021-11-01 16:00:00.030963124 +0800
Change: 2021-11-01 16:00:00.030963124 +0800
Birth: -
[root@rocky8 ~]# at now+1minutes
warning: commands will be executed using /bin/sh
at> echo $PATH
at> echo hello
at> hostname
at> <EOT>
job 2 at Mon Nov 1 16:03:00 2021
root@rocky8 ~]# mail
Heirloom Mail version 12.5 7/5/10. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root Mon Nov 1 16:03 16/545 "Output from your job 2"
& 1
Message 1:
From root@rocky8.localdomain Mon Nov 1 16:03:07 2021
Return-Path: <root@rocky8.localdomain>
X-Original-To: root
Delivered-To: root@rocky8.localdomain
Subject: Output from your job 2
To: root@rocky8.localdomain
Date: Mon, 1 Nov 2021 16:03:07 +0800 (CST)
From: root <root@rocky8.localdomain>
Status: R
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin
hello
rocky8
[root@rocky8 ~]# echo hostname | at now+1min
warning: commands will be executed using /bin/sh
job 3 at Mon Nov 1 16:05:00 2021
[root@rocky8 ~]# at -l
3 Mon Nov 1 16:05:00 2021 a root
[root@rocky8 ~]# at -c 3
#!/bin/sh
# atrun uid=0 gid=0
# mail root 0
umask 22
LS_COLORS=rs=0:di=01\;34:ln=01\;36:mh=00:pi=40\;33:so=01\;35:do=01\;35:bd=40\;33\;01:cd=40\;33\;01:or=40\;31\;01:mi=01\;05\;37\;41:su=37\;41:sg=30\;43:ca=30\;41:tw=30\;42:ow=34\;42:st=37\;44:ex=01\;32:\*.tar=01\;31:\*.tgz=01\;31:\*.arc=01\;31:\*.arj=01\;31:\*.taz=01\;31:\*.lha=01\;31:\*.lz4=01\;31:\*.lzh=01\;31:\*.lzma=01\;31:\*.tlz=01\;31:\*.txz=01\;31:\*.tzo=01\;31:\*.t7z=01\;31:\*.zip=01\;31:\*.z=01\;31:\*.dz=01\;31:\*.gz=01\;31:\*.lrz=01\;31:\*.lz=01\;31:\*.lzo=01\;31:\*.xz=01\;31:\*.zst=01\;31:\*.tzst=01\;31:\*.bz2=01\;31:\*.bz=01\;31:\*.tbz=01\;31:\*.tbz2=01\;31:\*.tz=01\;31:\*.deb=01\;31:\*.rpm=01\;31:\*.jar=01\;31:\*.war=01\;31:\*.ear=01\;31:\*.sar=01\;31:\*.rar=01\;31:\*.alz=01\;31:\*.ace=01\;31:\*.zoo=01\;31:\*.cpio=01\;31:\*.7z=01\;31:\*.rz=01\;31:\*.cab=01\;31:\*.wim=01\;31:\*.swm=01\;31:\*.dwm=01\;31:\*.esd=01\;31:\*.jpg=01\;35:\*.jpeg=01\;35:\*.mjpg=01\;35:\*.mjpeg=01\;35:\*.gif=01\;35:\*.bmp=01\;35:\*.pbm=01\;35:\*.pgm=01\;35:\*.ppm=01\;35:\*.tga=01\;35:\*.xbm=01\;35:\*.xpm=01\;35:\*.tif=01\;35:\*.tiff=01\;35:\*.png=01\;35:\*.svg=01\;35:\*.svgz=01\;35:\*.mng=01\;35:\*.pcx=01\;35:\*.mov=01\;35:\*.mpg=01\;35:\*.mpeg=01\;35:\*.m2v=01\;35:\*.mkv=01\;35:\*.webm=01\;35:\*.ogm=01\;35:\*.mp4=01\;35:\*.m4v=01\;35:\*.mp4v=01\;35:\*.vob=01\;35:\*.qt=01\;35:\*.nuv=01\;35:\*.wmv=01\;35:\*.asf=01\;35:\*.rm=01\;35:\*.rmvb=01\;35:\*.flc=01\;35:\*.avi=01\;35:\*.fli=01\;35:\*.flv=01\;35:\*.gl=01\;35:\*.dl=01\;35:\*.xcf=01\;35:\*.xwd=01\;35:\*.yuv=01\;35:\*.cgm=01\;35:\*.emf=01\;35:\*.ogv=01\;35:\*.ogx=01\;35:\*.aac=01\;36:\*.au=01\;36:\*.flac=01\;36:\*.m4a=01\;36:\*.mid=01\;36:\*.midi=01\;36:\*.mka=01\;36:\*.mp3=01\;36:\*.mpc=01\;36:\*.ogg=01\;36:\*.ra=01\;36:\*.wav=01\;36:\*.oga=01\;36:\*.opus=01\;36:\*.spx=01\;36:\*.xspf=01\;36:; export LS_COLORS
SSH_CONNECTION=172.31.0.1\ 53218\ 172.31.1.8\ 22; export SSH_CONNECTION
LANG=en_US.UTF-8; export LANG
HISTCONTROL=ignoredups; export HISTCONTROL
HISTTIMEFORMAT=%F\ %T\ ; export HISTTIMEFORMAT
HOSTNAME=rocky8; export HOSTNAME
EDITOR=vim; export EDITOR
XDG_SESSION_ID=1; export XDG_SESSION_ID
USER=root; export USER
PWD=/root; export PWD
HOME=/root; export HOME
SSH_CLIENT=172.31.0.1\ 53218\ 22; export SSH_CLIENT
SSH_TTY=/dev/pts/0; export SSH_TTY
MAIL=/var/spool/mail/root; export MAIL
SHELL=/bin/bash; export SHELL
SHLVL=1; export SHLVL
LOGNAME=root; export LOGNAME
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/0/bus; export DBUS_SESSION_BUS_ADDRESS
XDG_RUNTIME_DIR=/run/user/0; export XDG_RUNTIME_DIR
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin; export PATH
HISTSIZE=1000; export HISTSIZE
LESSOPEN=\|\|/usr/bin/lesspipe.sh\ %s; export LESSOPEN
cd /root || {
echo 'Execution directory inaccessible' >&2
exit 1
}
${SHELL:-/bin/sh} << 'marcinDELIMITER1ce002e6'
hostname
marcinDELIMITER1ce002e6
[root@rocky8 ~]# ll -a /var/spool/at/
total 4
drwx------ 3 root root 31 Nov 1 16:05 .
drwxr-xr-x. 9 root root 97 Nov 1 15:31 ..
-rw------- 1 root root 6 Nov 1 16:04 .SEQ
drwx------ 2 root root 6 Nov 1 16:05 spool
[root@rocky8 ~]# vim at.txt
wall info
[root@rocky8 ~]# at -f at.txt now+1min
warning: commands will be executed using /bin/sh
job 4 at Mon Nov 1 16:09:00 2021
[root@rocky8 ~]# at -l
4 Mon Nov 1 16:09:00 2021 a root
到时间屏幕上会看到警告信息
[root@rocky8 ~]# su - raymond Last login: Sun Oct 31 19:45:13 CST 2021 on pts/2 [raymond@rocky8 ~]$ at now+2min warning: commands will be executed using /bin/sh at> ^C[raymond@rocky8 ~]$ exit logout #拒绝raymond用户创建at计划任务 [root@rocky8 ~]# vim /etc/at.deny raymond [root@rocky8 ~]# su - raymond Last login: Sun Oct 31 20:57:55 CST 2021 on pts/3 [raymond@rocky8 ~]$ at now+2min You do not have permission to use at. [raymond@rocky8 ~]$ exit logout #只允许raymond用户创建at计划任务 [root@rocky8 ~]# vim /etc/at.allow raymond [root@rocky8 ~]# su - raymond Last login: Sun Oct 31 20:59:45 CST 2021 on pts/3 [raymond@rocky8 ~]$ at now+2min warning: commands will be executed using /bin/sh at> ^C[raymond@rocky8 ~]$ exit logout [root@rocky8 ~]# useradd boss [root@rocky8 ~]# su - boss [boss@rocky8 ~]$ at now+2min You do not have permission to use at. [boss@rocky8 ~]$ exit logout #创建了/etc/at.allow文件，只有里边允许的才能创建计划任务 [root@rocky8 ~]# rm -f /etc/at.allow
范例: ubuntu at任务存放路径
root@ubuntu2004:~# ll /var/spool/cron/atjobs/ total 20 drwxrwx--T 2 daemon daemon 4096 Oct 31 12:40 ./ drwxr-xr-x 5 root root 4096 Aug 24 08:46 ../ -rwx------ 1 root daemon 2902 Oct 31 12:37 a00001019ffb18* -rwx------ 1 root daemon 2895 Oct 31 12:37 a00002019ffb18* -rw------- 1 daemon daemon 6 Oct 31 12:39 .SEQ
3.2 周期性任务计划 cron
周期性任务计划cron相关的程序包：
- cronie：主程序包，提供crond守护进程及相关辅助工具
- crontabs：包含CentOS提供系统维护任务
- cronie-anacron：cronie的补充程序，用于监控cronie任务执行状况，如:cronie中的任务在过去该运行的时间点未能正常运行，则anacron会随后启动一次此任务
cron 依赖于crond服务，确保crond守护处于运行状态：
#CentOS 7 以后版本: systemctl status crond #CentOS 6: service crond status
cron任务分为
- 系统cron任务：系统维护作业，/etc/crontab 主配置文件， /etc/cron.d/ 子配置文件
- 用户cron任务：保存在 /var/spool/cron/USERNAME，利用 crontab 命令管理
计划任务日志：/var/log/cron
范例：
root@rocky8 ~]# rpm -ql cronie
/etc/cron.d
/etc/cron.d/0hourly
/etc/cron.deny
/etc/pam.d/crond
/etc/sysconfig/crond
/lib/systemd/system/crond.service
/usr/bin/cronnext
/usr/bin/crontab
/usr/lib/.build-id
/usr/lib/.build-id/02
/usr/lib/.build-id/02/fc08d45998b2b12ac76b2c6993c2053dae1103
/usr/lib/.build-id/73
/usr/lib/.build-id/73/571ebb01669fc6683ae3c87375d1e79018d3fc
/usr/lib/.build-id/90
/usr/lib/.build-id/90/924a16123825d3f422be80ab8e78c7ef4055f1
/usr/sbin/crond
/usr/share/doc/cronie
/usr/share/doc/cronie/AUTHORS
/usr/share/doc/cronie/ChangeLog
/usr/share/doc/cronie/README
/usr/share/licenses/cronie
/usr/share/licenses/cronie/COPYING
/usr/share/man/man1/cronnext.1.gz
/usr/share/man/man1/crontab.1.gz
/usr/share/man/man5/crontab.5.gz
/usr/share/man/man8/cron.8.gz
/usr/share/man/man8/crond.8.gz
/var/spool/cron
[root@rocky8 ~]# systemctl status crond
● crond.service - Command Scheduler
Loaded: loaded (/usr/lib/systemd/system/crond.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2021-10-31 13:03:50 CST; 8h ago
Main PID: 843 (crond)
Tasks: 1 (limit: 4783)
Memory: 964.0K
CGroup: /system.slice/crond.service
└─843 /usr/sbin/crond -n
Oct 31 15:01:01 rocky8 CROND[10612]: (root) CMD (run-parts /etc/cron.hourly)
Oct 31 15:19:01 rocky8 anacron[10005]: Job `cron.monthly' started
Oct 31 15:19:01 rocky8 anacron[10005]: Job `cron.monthly' terminated
Oct 31 15:19:01 rocky8 anacron[10005]: Normal exit (3 jobs run)
Oct 31 16:01:01 rocky8 CROND[10694]: (root) CMD (run-parts /etc/cron.hourly)
Oct 31 17:01:01 rocky8 CROND[11521]: (root) CMD (run-parts /etc/cron.hourly)
Oct 31 18:01:01 rocky8 CROND[16118]: (root) CMD (run-parts /etc/cron.hourly)
Oct 31 19:01:01 rocky8 CROND[17325]: (root) CMD (run-parts /etc/cron.hourly)
Oct 31 20:01:01 rocky8 CROND[22535]: (root) CMD (run-parts /etc/cron.hourly)
Oct 31 21:01:01 rocky8 CROND[27058]: (root) CMD (run-parts /etc/cron.hourly)
3.2.1 系统cron计划任务
/etc/crontab 格式说明，详情参见 man 5 crontab
注释行以 # 开头
[root@rocky8 ~]# cat /etc/crontab SHELL=/bin/bash #默认的SHELL类型 PATH=/sbin:/bin:/usr/sbin:/usr/bin #默认的PATH变量值,可修改为其它路径 MAILTO=root #默认标准输出和错误发邮件给root,可以指向其它用户 # For details see man 4 crontabs # Example of job definition: # .---------------- minute (0 - 59) # | .------------- hour (0 - 23) # | | .---------- day of month (1 - 31) # | | | .------- month (1 - 12) OR jan,feb,mar,apr ... # | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat # | | | | | # * * * * * user-name command to be executed root@ubuntu2004:~# cat /etc/crontab # /etc/crontab: system-wide crontab # Unlike any other crontab you don't have to run the `crontab' # command to install the new version when you edit this file # and files in /etc/cron.d. These files also have username fields, # that none of the other crontabs do. SHELL=/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin # Example of job definition: # .---------------- minute (0 - 59) # | .------------- hour (0 - 23) # | | .---------- day of month (1 - 31) # | | | .------- month (1 - 12) OR jan,feb,mar,apr ... # | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat # | | | | | # * * * * * user-name command to be executed 17 * * * * root cd / && run-parts --report /etc/cron.hourly 25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily ) 47 6 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly ) 52 6 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly ) # root@ubuntu2004:~# which run-parts /usr/bin/run-parts root@ubuntu2004:~# file `which run-parts` /usr/bin/run-parts: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=6017e923e9756db667c617f5a9fc12cb5276d74a, for GNU/Linux 3.2.0, stripped [root@rocky8 ~]# file `which run-parts` /usr/bin/run-parts: Bourne-Again shell script, ASCII text executable [root@rocky8 opt]# vim f1.sh #!/bin/bash # #********************************************************************************************** #Author: Raymond #QQ: 88563128 #Date: 2021-10-31 #FileName: f1.sh #URL: raymond.blog.csdn.net #Description: The test script #Copyright (C): 2021 All rights reserved #********************************************************************************************* echo f1.sh [root@rocky8 opt]# vim f2.sh #!/bin/bash # #********************************************************************************************** #Author: Raymond #QQ: 88563128 #Date: 2021-10-31 #FileName: f2.sh #URL: raymond.blog.csdn.net #Description: The test script #Copyright (C): 2021 All rights reserved #********************************************************************************************* echo f2.sh [root@rocky8 opt]# cd [root@rocky8 ~]# chmod +x /opt/* [root@rocky8 ~]# ll /opt/ total 8 -rwxr-xr-x 1 root root 426 Oct 31 21:29 f1.sh -rwxr-xr-x 1 root root 425 Oct 31 21:29 f2.sh [root@rocky8 ~]# run-parts /opt /opt/f1.sh: f1.sh /opt/f2.sh: f2.sh [root@rocky8 ~]# crontab -e * 21 * * 0 echo $PATH [root@rocky8 ~]# crontab -e 30 2 1-10 * 6,0 echo $PATH #这个命令在2点30，或1-10号，或周六/周日执行
计划任务时间表示法：
(1) 特定值
给定时间点有效取值范围内的值
(2) *
给定时间点上有效取值范围内的所有值
表示“每...”
(3) 离散取值
#,#,#
(4) 连续取值
#-#
(5) 在指定时间范围上，定义步长
/#: #即为步长
(6) 特定关健字
@yearly 0 0 1 1 *
@annually 0 0 1 1 *
@monthly 0 0 1 * *
@weekly 0 0 * * 0
@daily 0 0 * * *
@hourly 0 * * * *
@reboot Run once after reboot
范例：
#晚上9点10分运行echo命令 10 21 * * * raymond /bin/echo "Howdy!" #每3小时echo和wall命令 0 */3 * * * raymond /bin/echo “howdy”; wall “welcome to Linux!”
crond任务相关文件:
/etc/crontab 配置文件 /etc/cron.d/ 配置文件 /etc/cron.hourly/ 脚本 /etc/cron.daily/ 脚本 /etc/cron.weekly/ 脚本 /etc/cron.monthly/ 脚本
3.2.2 用户计划任务
crontab命令:
- 每个用户都有专用的cron任务文件：/var/spool/cron/USERNAME
- 默认标准输出和错误会被发邮件给对应的用户,如：wang创建的任务就发送至wang的邮箱
- root能够修改其它用户的作业
- 用户的cron 中默认 PATH=/usr/bin:/bin,如果使用其它路径,在任务文件的第一行加PATH=/path或者加入到计划任务执行的脚本中
crontab命令格式：
crontab [-u user] [-l | -r | -e] [-i]
常用选项：
-l 列出所有任务 -e 编辑任务 -r 移除所有任务 -i 同-r一同使用，以交互式模式移除指定任务 -u user 仅root可运行，指定用户管理cron任务
控制用户执行计划任务：
/etc/cron.{allow,deny}
范例：每个月日期和星期几字段的关系
[root@rocky8 ~]# crontab -e
30 2 1-10 * 6,0 echo $PATH
#这个命令在2点30，或1-10号，或周六/周日执行
[root@rocky8 ~]# man 5 crontab
Note: The day of a command's execution can be specified in the following two fields — 'day of month', and 'day of week'. If both
fields are restricted (i.e., do not contain the "*" character), the command will be run when either field matches the current time.
For example,
"30 4 1,15 * 5" would cause a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday.
[root@rocky8 ~]# crontab -e
30 2 1-10 * * echo $PATH
[root@rocky8 data]# vim test.sh
#!/bin/bash
#
#**********************************************************************************************
#Author: Raymond
#QQ: 88563128
#Date: 2021-11-01
#FileName: test.sh
#URL: raymond.blog.csdn.net
#Description: The test script
#Copyright (C): 2021 All rights reserved
#*********************************************************************************************
[ `date +%w` -eq 0 -o `date +%w` -eq 6 ] && run
#如果表示1-10，并且是周六/周日，在脚本里判断
范例：
[root@rocky8 ~]# crontab -r #删除计划任务 [root@rocky8 ~]# su - raymond Last login: Sun Oct 31 21:01:14 CST 2021 on pts/3 [raymond@rocky8 ~]$ crontab -e no crontab for raymond - using an empty one [raymond@rocky8 ~]$ exit logout [root@rocky8 ~]# vim /etc/cron.deny raymond [root@rocky8 ~]# su - raymond Last login: Sun Oct 31 21:41:36 CST 2021 on pts/3 [raymond@rocky8 ~]$ crontab -e You (raymond) are not allowed to use this program (crontab) See crontab(1) for more information [raymond@rocky8 ~]$ exit logout #把raymond用户加入/etc/cron.deny，他就不能创建计划任务 root@ubuntu2004:~# cat /etc/rsyslog.d/*.conf # Log cloudinit generated log messages to file :syslogtag, isequal, "[CLOUDINIT]" /var/log/cloud-init.log # comment out the following line to allow CLOUDINIT messages through. # Doing so means you'll also get CLOUDINIT messages in /var/log/syslog & stop # Default rules for rsyslog. # # For more information see rsyslog.conf(5) and /etc/rsyslog.conf # # First some standard log files. Log by facility. # auth,authpriv.* /var/log/auth.log *.*;auth,authpriv.none -/var/log/syslog #cron.* /var/log/cron.log #计划任务日志被禁用 #daemon.* -/var/log/daemon.log kern.* -/var/log/kern.log #lpr.* -/var/log/lpr.log mail.* -/var/log/mail.log #user.* -/var/log/user.log # # Logging for the mail system. Split it up so that # it is easy to write scripts to parse these files. # #mail.info -/var/log/mail.info #mail.warn -/var/log/mail.warn mail.err /var/log/mail.err # # Some "catch-all" log files. # #*.=debug;\ # auth,authpriv.none;\ # news.none;mail.none -/var/log/debug #*.=info;*.=notice;*.=warn;\ # auth,authpriv.none;\ # cron,daemon.none;\ # mail,news.none -/var/log/messages # # Emergencies are sent to everybody logged in. # *.emerg :omusrmsg:* # # I like to have messages displayed on the console, but only on a virtual # console I usually leave idle. # #daemon,mail.*;\ # news.=crit;news.=err;news.=notice;\ # *.=debug;*.=info;\ # *.=notice;*.=warn /dev/tty8 # Create an additional socket in postfix's chroot in order not to break # mail logging when rsyslog is restarted. If the directory is missing, # rsyslog will silently skip creating the socket. $AddUnixListenSocket /var/spool/postfix/dev/log
范例：修改默认的cron的文本编辑工具
root@ubuntu2004:~# crontab -e no crontab for root - using an empty one Select an editor. To change later, run 'select-editor'. 1. /bin/nano <---- easiest 2. /usr/bin/vim.basic 3. /usr/bin/vim.tiny 4. /bin/ed Choose 1-4 [1]: root@ubuntu1804:~# vim .bashrc export EDITOR=vim
范例：PATH变量
#方法1,在计划任务配置中指定PATH [root@rocky8 ~]# crontab -l PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin * * * * * useradd hehe;echo $PATH #方法2,在脚本中指定PATH变量 [root@rocky8 ~]# crontab -l * * * * * /data/test.sh [root@rocky8 ~]# cat /data/test.sh #!/bin/bash PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin useradd hehe
范例：
[root@rocky8 ~]# cd /data
[root@rocky8 data]# vim disk_check.sh
#!/bin/bash
#
#**********************************************************************************************
#Author: Raymond
#QQ: 88563128
#Date: 2021-10-31
#FileName: disk_check.sh
#URL: raymond.blog.csdn.net
#Description: The test script
#Copyright (C): 2021 All rights reserved
#*********************************************************************************************
WARNING=80
df | sed -En '/^\/dev\/sd/s@^([^ ]+).* ([0-9]+)%.*@\1 \2@p'| while read DEVICE USE;do
[ $USE -gt $WARNING ] && echo "$DEVICE will be full,USE:$USE" | mail -s diskfull root
done
[root@rocky8 data]# chmod +x disk_check.sh
[root@rocky8 data]# crontab -e
*/10 * * * * /data/disk_check.sh
面试题：每年11月每天的6-12点之间每隔2小时执行/app/bin/test.sh
#在6,8,10,12点整共4次分别执行test.sh [root@rocky8 ~]# crontab -l 0 6-12/2 * 11 * /app/bin/test.sh #以下配置只会在5,7,9,11点整执行 0 5-12/2 * 11 * /app/bin/test.sh
注意：运行结果的标准输出和错误以邮件通知给相关用户
(1) COMMAND > /dev/null
(2) COMMAND &> /dev/null
cron任务中不建议使用%，它有特殊用途，它表示换行的特殊意义，且第一个%后的所有字符串会被将成当作命令的标准输入
如果在命令中要使用%，则需要用 \ 转义
注意：将%放置于单引号中是不支持的
范例：
30 2 * * * /bin/cp -a /etc/ /data/etc`date +\%F_\%T` 30 2 * * * /bin/cp -a /etc/ /data/etc`date +‘%F_%T’` 有问题
范例：
[root@rocky8 ~]# crontab -e * * * * * date +%F > /data/date.log [root@rocky8 ~]# tail -f /var/log/cron Nov 2 17:01:01 rocky8 run-parts[1385]: (/etc/cron.hourly) finished 0anacron Nov 2 17:16:01 rocky8 anacron[1333]: Job `cron.monthly' started Nov 2 17:16:01 rocky8 anacron[1333]: Job `cron.monthly' terminated Nov 2 17:16:01 rocky8 anacron[1333]: Normal exit (3 jobs run) Nov 2 17:21:55 rocky8 crontab[1401]: (root) BEGIN EDIT (root) Nov 2 17:22:15 rocky8 crontab[9590]: (root) BEGIN EDIT (root) Nov 2 17:23:14 rocky8 crontab[9590]: (root) REPLACE (root) Nov 2 17:23:14 rocky8 crontab[9590]: (root) END EDIT (root) Nov 2 17:24:01 rocky8 CROND[9594]: (root) CMD (date +) #它把%当换行了，后面的不执行 Nov 2 17:24:10 rocky8 crontab[9597]: (root) LIST (root) [root@rocky8 ~]# ll /data/date.log ls: cannot access '/data/date.log': No such file or directory #文件也没用创建 [root@rocky8 ~]# crontab -e * * * * * date +\%F > /data/date.log #%前面加转义符\ [root@rocky8 ~]# tail -f /var/log/cron ... Nov 2 17:27:01 rocky8 crond[820]: (root) RELOAD (/var/spool/cron/root) Nov 2 17:27:01 rocky8 CROND[9612]: (root) CMD (date +%F > /data/date.log) #现在就执行正常了 [root@rocky8 ~]# ll /data/date.log -rw-r--r-- 1 root root 11 Nov 2 17:28 /data/date.log [root@rocky8 ~]# cat /data/date.log 2021-11-02 [root@rocky8 ~]# rm -f /data/date.log [root@rocky8 ~]# vim test.sh #!/bin/bash # #********************************************************************************************** #Author: Raymond #QQ: 88563128 #Date: 2021-11-02 #FileName: test.sh #URL: raymond.blog.csdn.net #Description: The test script #Copyright (C): 2021 All rights reserved #********************************************************************************************* date +%F > /data/date.log [root@rocky8 ~]# chmod +x test.sh [root@rocky8 ~]# crontab -e * * * * * /root/test.sh #也可以把命令写到脚本，直接运行脚本，建议使用此方式 [root@rocky8 ~]# tail -f /var/log/cron ... Nov 2 17:54:01 rocky8 crond[820]: (root) RELOAD (/var/spool/cron/root) Nov 2 17:54:01 rocky8 CROND[9737]: (root) CMD (/root/test.sh) [root@rocky8 ~]# ll /data/date.log -rw-r--r-- 1 root root 11 Nov 2 17:54 /data/date.log
思考：
(1) 如何在秒级别运行任务？
for min in 0 1 2; do echo "hi"; sleep 20; done
范例：
#每10秒执行一次 [root@rocky8 ~]# while true ;do ls -l test.sh ;sleep 10;done -rwxr-xr-x 1 root root 442 Nov 2 17:52 test.sh -rwxr-xr-x 1 root root 442 Nov 2 17:52 test.sh ^C [root@rocky8 ~]# watch -n10 ls -l test.sh #watch -n10 每10秒执行一次查看 Every 10.0s: ls -l test.sh rocky8: Tue Nov 2 18:10:11 2021 -rwxr-xr-x 1 root root 442 Nov 2 17:52 test.sh
(2) 如何实现每7分钟运行一次任务?
sleep命令：
sleep NUMBER[SUFFIX]... SUFFIX: s: 秒, 默认 m: 分 h: 小时 d: 天
范例：
#每7分钟执行一次 [root@rocky8 ~]# while true ;do ls -l test.sh ;sleep 7m;done -rwxr-xr-x 1 root root 442 Nov 2 17:52 test.sh
3.3 练习
1、每周的工作日1：30，将/etc备份至/backup目录中，保存的文件名称格式为“etcbak-yyyy-mm-dd-HH.tar.xz”，其中日期是前一天的时间
2、每两小时取出当前系统/proc/meminfo文件中以S或M开头的信息追加至/tmp/meminfo.txt文件中
3、工作日时间，每10分钟执行一次磁盘空间检查，一旦发现任何分区利用率高于80%，就执行wall警报
这篇关于51.第十一章 进程和计划任务(三)的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！
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