Go环境变量实例
Go环境变量实例
环境变量是一种用于将配置信息传递到Unix程序的通用机制。我们来看看如何设置，获取和列出环境变量。
所有的示例代码，都放在
F:\worksp\golang目录下。安装Go编程环境请参考：/tutorial/detail-5562.html
command-line-flags.go的完整代码如下所示 -
package main
import "os"
import "strings"
import "fmt"
func main() {
// To set a key/value pair, use `os.Setenv`. To get a
// value for a key, use `os.Getenv`. This will return
// an empty string if the key isn't present in the
// environment.
os.Setenv("FOO", "1")
fmt.Println("FOO:", os.Getenv("FOO"))
fmt.Println("BAR:", os.Getenv("BAR"))
// Use `os.Environ` to list all key/value pairs in the
// environment. This returns a slice of strings in the
// form `KEY=value`. You can `strings.Split` them to
// get the key and value. Here we print all the keys.
fmt.Println()
for _, e := range os.Environ() {
pair := strings.Split(e, "=")
fmt.Println(pair[0])
}
}
执行上面代码，将得到以下输出结果 -
F:\worksp\golang>go run environment-variables.go FOO: 1 BAR: ALLUSERSPROFILE ANDROID_HOME APPDATA asl.log CommonProgramFiles CommonProgramFiles(x86) CommonProgramW6432 COMMPath COMPUTERNAME ComSpec FOO FPS_BROWSER_APP_PROFILE_STRING FPS_BROWSER_USER_PROFILE_STRING FP_NO_HOST_CHECK GOROOT HOMEDRIVE HOMEPATH JAVA_HOME LOCALAPPDATA LOGONSERVER M2_HOME MAVEN_HOME MYSQLCONNECTOR_ASSEMBLIESPATH NUMBER_OF_PROCESSORS OPENSSL_CONF OS Path PATHEXT PROCESSOR_ARCHITECTURE PROCESSOR_IDENTIFIER PROCESSOR_LEVEL PROCESSOR_REVISION ProgramData ProgramFiles ProgramFiles(x86) ProgramW6432 PROMPT PSModulePath PUBLIC SESSIONNAME SystemDrive SystemRoot TEMP TMP USERDOMAIN USERDOMAIN_ROAMINGPROFILE USERNAME USERPROFILE VS140COMNTOOLS windir windows_tracing_flags windows_tracing_logfile
目录
Go编程代码实例
