Linux export command

Linux Command大全

The Linux 'export' command is used to set or display environment variables.

When executing a program in the shell, the shell will provide a set of environment variables. The 'export' command can add, modify, or delete environment variables for use by subsequent executing programs. The effect of 'export' is limited to the current login operation.

Syntax

export [-fnp][variable name]=[variable setting value]

Parameter description:

• -f 　Represents the function name in [variable name].
• -n 　Delete the specified variable. The variable is not actually deleted, it just will not be output to the execution environment of subsequent instructions.
• -p 　List all shell-assigned environment variables to programs.

Online examples

List all current environment variables

# export -p //List the current environment variable values
declare -x HOME="/root"
declare -x LANG="zh_CN.UTF"-8"
declare -x LANGUAGE="zh_CN:zh"
declare -x LESSCLOSE="/usr/bin/lesspipe %s %s"
declare -x LESSOPEN="|" /usr/bin/lesspipe %s"
declare -x LOGNAME="root"
declare -x LS_COLORS=""
declare -x MAIL="/var/mail/root"
declare -x OLDPWD
declare -x PATH="/opt/toolchains/arm920t-eabi/bin:/opt/toolchains/arm920t-eabi/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
declare -x PWD="/root"
declare -x SHELL="/bin/bash
declare -x SHLVL="1"
declare -x SPEECHD_PORT="6560"
declare -x SSH_CLIENT="192.168.1.65 1674 22"
declare -x SSH_CONNECTION="192.168.1.65 1674 192.168.1.3 22"
declare -x SSH_TTY="/dev/pts/2"
declare -x TERM="XTERM"
declare -x USER="root"
declare -x XDG_SESSION_COOKIE="93b5d3d03e032c0cf892a4474bebda9f-1273864738.954257-340206484"

Define environment variable

# export MYENV //Define environment variable
# export -p //List current environment variables
declare -x HOME="/root"
declare -x LANG="zh_CN.UTF"-8"
declare -x LANGUAGE="zh_CN:zh"
declare -x LESSCLOSE="/usr/bin/lesspipe %s %s"
declare -x LESSOPEN="|" /usr/bin/lesspipe %s"
declare -x LOGNAME="root"
declare -x LS_COLORS=""
declare -x MAIL="/var/mail/root"
declare -x MYENV
declare -x OLDPWD
declare -x PATH="/opt/toolchains/arm920t-eabi/bin:/opt/toolchains/arm920t-eabi/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
declare -x PWD="/root"
declare -x SHELL="/bin/bash
declare -x SHLVL="1"
declare -x SPEECHD_PORT="6560"
declare -x SSH_CLIENT="192.168.1.65 1674 22"
declare -x SSH_CONNECTION="192.168.1.65 1674 192.168.1.3 22"
declare -x SSH_TTY="/dev/pts/2"
declare -x TERM="XTERM"
declare -x USER="root"
declare -x XDG_SESSION_COOKIE="93b5d3d03e032c0cf892a4474bebda9f-1273864738.954257-340206484"

Define environment variable assignment

# export MYENV=7 //Define environment variables and assign values
# export -p
declare -x HOME="/root"
declare -x LANG="zh_CN.UTF"-8"
declare -x LANGUAGE="zh_CN:zh"
declare -x LESSCLOSE="/usr/bin/lesspipe %s %s"
declare -x LESSOPEN="|" /usr/bin/lesspipe %s"
declare -x LOGNAME="root"
declare -x LS_COLORS=""
declare -x MAIL="/var/mail/root"
declare -x MYENV="7"
declare -x OLDPWD
declare -x PATH="/opt/toolchains/arm920t-eabi/bin:/opt/toolchains/arm920t-eabi/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
declare -x PWD="/root"
declare -x SHELL="/bin/bash
declare -x SHLVL="1"
declare -x SPEECHD_PORT="6560"
declare -x SSH_CLIENT="192.168.1.65 1674 22"
declare -x SSH_CONNECTION="192.168.1.65 1674 192.168.1.3 22"
declare -x SSH_TTY="/dev/pts/2"
declare -x TERM="XTERM"
declare -x USER="root"
declare -x XDG_SESSION_COOKIE="93b5d3d03e032c0cf892a4474bebda9f-1273864738.954257-340206484"

Linux Command大全