Change the value of a shell option and set the positional parameters, or display the names and values of shell variables.
Syntax set [--abefhkmnptuvxBCEHPT] [-o option-name] [argument …] set [+abefhkmnptuvxBCEHPT] [+o option-name] [argument …]
If no options or arguments are supplied, set displays the names and values of all shell variables and functions, sorted according to the current locale, in a format that can be reused as input. When options are supplied, they set or unset shell attributes.
Options Using + rather than - will cause the option to be turned off. -a Mark variables which are modified or created for export. -o allexport -b Cause the status of terminated background jobs to be reported immediately, rather than before printing the next primary prompt. -o notify -B The shell will perform brace expansion. This option is on by default. -o braceexpand -C Prevent output redirection using '>', '>&', and '<>' from overwriting existing files. -o noclobber -e Exit immediately if a simple command exits with a non-zero status, unless the command that fails is part of an until or while loop, part of an if statement, part of a && or || list, or if the command's return status is being inverted using !. -o errexit -f Disable file name generation (globbing). -o noglob -h Locate and remember (hash) commands as they are looked up for execution. This option is enabled by default. -o hashall