Linux shell的变量功能
//系统默认的语系[root@localhost home]# cat /etc/sysconfig/i18nLANG="zh_CN.GB18030"LANGUAGE="zh_CN.GB18030:zh_CN.GB2312:zh_CN"SUPPORTED="zh_CN.GB18030:zh_CN:zh:en_GB.UTF-8:en_GB:en"SYSFONT="lat0-sun16"SYSFONTACM="8859-15"
//本系统所支持的语系[root@localhost home]# locale -a... yi_USyi_US.cp1255zh_CNzh_CN.gb18030zh_CN.gb2312zh_CN.gbkzh_CN.utf8zh_HKzh_HK.big5hkscszh_HK.utf8zh_TWzh_TW.big5zh_TW.euctwzh_TW.utf8
//查看环境变量[root@localhost home]# exportdeclare -x BASH_ENV="/root/.bashrc"declare -x G_BROKEN_FILENAMES="1"declare -x HISTSIZE="1000"declare -x HOME="/root"declare -x HOSTNAME="localhost.localdomain"declare -x INPUTRC="/etc/inputrc"declare -x LANG="zh_CN.GB18030"declare -x LANGUAGE="zh_CN.GB18030:zh_CN.GB2312:zh_CN"declare -x LESSOPEN="|/usr/bin/lesspipe.sh %s"declare -x LOGNAME="root"declare -x LS_COLORS="no=00:fi=00:di=00;34:ln=00;36:pi=40;33:so=00;35:bd=40;33;01:cd=40;33;01:or=01;05;37;41:mi=01;05;37;41:ex=00;32:*.cmd=00;32:*.exe=00;32:*.com=00;32:*.btm=00;32:*.bat=00;32:*.sh=00;32:*.csh=00;32:*.tar=00;31:*.tgz=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.zip=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.bz=00;31:*.tz=00;31:*.rpm=00;31:*.cpio=00;31:*.jpg=00;35:*.gif=00;35:*.bmp=00;35:*.xbm=00;35:*.xpm=00;35:*.png=00;35:*.tif=00;35:"declare -x MAIL="/var/spool/mail/root"declare -x OLDPWD="/root"declare -x PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin"declare -x PWD="/home"declare -x SHELL="/bin/bash"declare -x SHLVL="1"declare -x SSH_ASKPASS="/usr/libexec/openssh/gnome-ssh-askpass"declare -x SSH_CLIENT="192.168.26.195 3176 22"declare -x SSH_CONNECTION="192.168.26.195 3176 192.168.26.146 22"declare -x SSH_TTY="/dev/pts/2"declare -x TERM="xterm"declare -x USER="root"declare -x USERNAME="root"[root@localhost home]#
//主机硬件与内核的等级[root@localhost home]# echo $OSTYPElinux-gnu[root@localhost home]# echo $HOSTTYPEi386[root@localhost home]# echo $MACHTYPEi386-redhat-linux-gnu
//错误代码回传码[root@localhost home]# echo $SHELL/bin/bash[root@localhost home]# echo $?0[root@localhost home]# 12name=VBird-bash: 12name=VBird: command not found[root@localhost home]# echo $?127
[root@localhost home]# echo $$16374[root@localhost home]#
[root@localhost root]# echo $RANDOM25882[root@localhost root]# declare -i number=$RANDOM*10/32768;echo $number5
[root@localhost root]# envHOSTNAME=localhost.localdomainTERM=xtermSHELL=/bin/bashHISTSIZE=1000SSH_CLIENT=192.168.26.195 2147 22SSH_TTY=/dev/pts/1USER=rootLS_COLORS=no=00:fi=00:di=00;34:ln=00;36:pi=40;33:so=00;35:bd=40;33;01:cd=40;33;01:or=01;05;37;41:mi=01;05;37;41:ex=00;32:*.cmd=00;32:*.exe=00;32:*.com=00;32:*.btm=00;32:*.bat=00;32:*.sh=00;32:*.csh=00;32:*.tar=00;31:*.tgz=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.zip=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.bz=00;31:*.tz=00;31:*.rpm=00;31:*.cpio=00;31:*.jpg=00;35:*.gif=00;35:*.bmp=00;35:*.xbm=00;35:*.xpm=00;35:*.png=00;35:*.tif=00;35:USERNAME=rootMAIL=/var/spool/mail/rootPATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/binINPUTRC=/etc/inputrcPWD=/rootLANG=zh_CN.GB18030SSH_ASKPASS=/usr/libexec/openssh/gnome-ssh-askpassSHLVL=1HOME=/rootLANGUAGE=zh_CN.GB18030:zh_CN.GB2312:zh_CNBASH_ENV=/root/.bashrcLOGNAME=rootSSH_CONNECTION=192.168.26.195 2147 192.168.26.146 22LESSOPEN=|/usr/bin/lesspipe.sh %sG_BROKEN_FILENAMES=1_=/bin/env[root@localhost root]#
[root@localhost root]# words="my kernel is $version"[root@localhost root]# echo $wordsmy kernel is 2.4.20-8[root@localhost root]# words='my kernel is $version'[root@localhost root]# echo $wordsmy kernel is $version
若变量需要在其他子进程执行，则需要以export来使变量成为环境变量[root@localhost root]# export PATH
[root@localhost root]# echo $version[root@localhost root]# version=$(uname -r)[root@localhost root]# echo $version2.4.20-8
[root@localhost root]# echo $myname[root@localhost root]# myname=xiongjiajia[root@localhost root]# echo $mynamexiongjiajia[root@localhost root]# unset myname[root@localhost root]# echo &myname
[root@localhost software]# software="/usr/mydocument/software"[root@localhost software]# cd $software
