linux系統(tǒng)下export命令是什么呢？下面是export命令具體介紹：

1、export命令簡(jiǎn)介：

Linux系統(tǒng)下export命令用于設(shè)置或顯示環(huán)境變量。在shell中執(zhí)行程序時(shí)，shell會(huì)提供一組環(huán)境變量。export可新增，修改或刪除環(huán)境變量，供后續(xù)執(zhí)行的程序使用。export的效力僅及于該次登陸操作。

2、語(yǔ)法：

export [-fnp][變量名稱]=[變量設(shè)置值]

3、參數(shù)說(shuō)明：

-f 　代表[變量名稱]中為函數(shù)名稱。

-n 　刪除指定的變量。變量實(shí)際上并未刪除，只是不會(huì)輸出到后續(xù)指令的執(zhí)行環(huán)境中。

-p 　列出所有的shell賦予程序的環(huán)境變量。

實(shí)例：

列出當(dāng)前所有的環(huán)境變量

# export -p //列出當(dāng)前的環(huán)境變量值

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(huán)境變量

# export MYENV //定義環(huán)境變量

# export -p //列出當(dāng)前的環(huán)境變量

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(huán)境變量賦值

# export MYENV=7 //定義環(huán)境變量并賦值

# 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“