The internal variables of shell scripting learning

One$BASH

　　　　The path of the Bash 's binary program file

　　

Two$BASH_ENV

This environment variable will point to a bash startup file that will be read when a script is called.

Three$BASH_SUBSHELL

This variable is used to indicate the level of the child shell

四, $BASH_VERSINFO[n]

This is an array of 6 elements that contains the version information of the bash that was installed

# Bash_versinfo[0] = 3                      # major version number.　　　　# Bash_versinfo[1] = xx                     # minor version number.　　　　# bash_versinfo[2] =                     # number of patches.　　　　# Bash_versinfo[3] = 1                      # compiled version.　　　　# Bash_versinfo[4] = release                # distribution status. # Bash_versinfo[5] = I386-redhat-linux-gnu  # structural system
Five$BASH_VERSION
　　　　安装在系统上的Bash版本号
　　　　

Six$DIRSTACK

The top-most value in the directory stack.

Seven$EDITOR

The default editor called by the script, usually vi or emacs.

Eight$EUID

　　　　"Valid" User ID

Nine$FUNCNAME

The name of the current function

　　　　

　　　　

Ten$GLOBIGNORE

A list of pattern matches for a file name, and if the file matched in the wildcard (globbing) contains a file in the list, the file will be removed from the matching result.

$GROUPS

This is a list of group IDs (arrays) for the current user, as is the content recorded in the /etc/passwd file.

Eleven$HOME

User's home directory

　　　

Twelve $HOSTNAME　

　　　　　　　

　　　　

13,$HOSTTYPE

Host type

　　　　

14,$IFS

Domain Segmentation

　　　　

　　　　

　

　　　　

The internal variables of shell scripting learning