CentOS修改系统环境变量
我这里拿PHP作为一个例子,我的PHP安装在/usr/local/webserver/PHP下,没有把PHP加入环境变量时,你在命令行执行
会提示你此命令不存在。
方法一: 在/etc/profile文件中添加变量【对所有用户生效(永久的)】
用VI在文件/etc/profile文件中增加变量,该变量将会对Linux下所有用户有效,并且是“永久的”。
[root@CentOS ~]# vi /etc/profile
在文件末尾加上如下两行代码
PATH=/usr/local/webserver/PHP/bin:$PATH
export PATH
# /etc/@H_301_35@profile # System wide environment and startup programs,for@H_301_35@ login setup # Functions and aliases go in /etc/@H_301_35@bashrc # It's NOT a good idea to change this file unless you know what you # are doing. Its much better to create a custom.sh shell script in # /etc/profile.d/ to make custom changes to your environment,as this@H_301_35@ # will prevent the need for merging in@H_301_35@ future updates. pathmunge () { case ":${PATH}:" in *:$1":*@H_301_35@) ;; *@H_301_35@) if [ $2" = after"@H_301_35@ ] ; then PATH=$PATH:$1 else@H_301_35@ PATH=$1@H_301_35@:$PATH fi esac } if [ -x /usr/bin/@H_301_35@id ]; then if [ -z $EUID"@H_301_35@ ]; then # ksh workaround EUID=`id -@H_301_35@u` UID=`id -@H_301_35@ru` fi USER=`id -un`"@H_301_35@ LOGNAME=@H_301_35@$USER MAIL=/var/spool/mail/$USER"@H_301_35@ fi # Path manipulation 0"@H_301_35@ ]; then pathmunge /@H_301_35@sbin pathmunge /usr/@H_301_35@sbin pathmunge /usr/local/@H_301_35@sbin else@H_301_35@ pathmunge /usr/local/@H_301_35@sbin after pathmunge /usr/@H_301_35@sbin after pathmunge /@H_301_35@sbin after fi HOSTNAME=`/bin/hostname 2>/dev/null@H_301_35@` HISTSIZE=1000 $HISTCONTROLignorespace"@H_301_35@ ] ; then export HISTCONTROL=@H_301_35@ignoreboth else@H_301_35@ export HISTCONTROL=@H_301_35@ignoredups fi export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL # By default,we want umask to get set. This sets it for@H_301_35@ login shell # Current threshold for system reserved uid/gids is 200@H_301_35@ # You could check uidgid reservation validity in@H_301_35@ # /usr/share/doc/setup-*/@H_301_35@uidgid file if [ $UID -gt 199 ] && [ `id -gn`"@H_301_35@ ]; then umask 002 else@H_301_35@ umask 022@H_301_35@ fi for i in /etc/profile.d/*.sh ; do if [ -r "$i" ]; then if [ "${-#*i}" != "$-" ]; then . "$i" else . "$i" >/dev/null 2>&1 fi fi done unset i unset pathmunge PATH=/usr/local/webserver/PHP/bin:$PATH export PATH
[root@CentOS ~]# source /etc/profile
这时再查看系统环境变量,就能看见刚才加的东西已经生效了
[root@CentOS ~@H_301_35@]# echo $PATH /usr/local/webserver/PHP/bin:/usr/lib/qt-3.3/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
现在就能直接使用PHP命令了(而不是像之前写很长一串/usr/local/webserver/PHP/bin/PHP -v),例如查看当前PHP的版本
[root@CentOS ~]# PHP -@H_301_35@v PHP 5.3.8 (cli) (built: Jun 27 2012 14:28:20@H_301_35@) Copyright (c) 1997-2011@H_301_35@ The PHP Group Zend Engine v2.3.0,Copyright (c) 1998-2011 Zend Technologies
方法二:在用户目录下的.bash_profile文件中增加变量【对单一用户生效(永久的)】
用VI在用户目录下的.bash_profile文件中增加变量,改变量仅会对当前用户有效,并且是“永久的”。具体操作和方法1一样,这里就不在列举代码了。
方法三:直接运行export命令定义变量【只对当前shell(BASH)有效(临时的)】
在shell的命令行下直接使用[export变量名=变量值]定义变量,该变量只在当前的shell(BASH)或其子shell(BASH)下是有效的,shell关闭了,变量也就失效了,再打开新shell时就没有这个变量,需要使用的话还需要重新定义。例如
export PATH=/usr/local/webserver/PHP/bin:$PATH