Pro Bash Programming: Scripting the GNU/Linux Shell

APPENDIXShell Variables

This list is excerpted from the bash man page and edited to make a stand-alone document. The following variables are set by bash.

BASH

Expands to the full file name used to invoke this instance of bash.

BASHPID

Expands to the process ID of the current bash process. This differs from $$ under certain circumstances, such as subshells that do not require bash to be reinitialized.

BASH_ALIASES

An associative array variable whose members correspond to the internal list of aliases as maintained by the alias builtin. Elements added to this array appear in the alias list; unsetting array elements causes aliases to be removed from the alias list.

BASH_ARGC

An array variable whose values are the number of parameters in each frame ...