Linux export命令詳解 Linux export命令怎麼用

在shell中執行程式時，shell會提供一組環境變數。export可新增，修改或刪除環境變數，供後續執行的程式使用。export的效力僅及於該次登陸操作。

文法

export [-fnp][變數名稱]=[變數設定值]

參數說明：

• -f  代表[變數名稱]中為函數名稱。
• -n  刪除指定的變數。變數實際上並未刪除，只是不會輸出到後續指令的執行環境中。
• -p  列出所有的shell賦予程式的環境變數。

執行個體

列出當前所有的環境變數

# export -p //列出當前的環境變數值

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“

定義環境變數

# export MYENV //定義環境變數

# export -p //列出當前的環境變數

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“

定義環境變數賦值

# export MYENV=7 //定義環境變數並賦值

# 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“