bash脚本编程基础

mitcmShellBashBashVimTerm伪用户

SHELL循环接收用户输入解释执行

KernelOS

硬盘网络用户 主机Login什么是LoginLogin时Bash

咦,/etc/profile.d/SUSE:SLK：LoginloginshloginbashLoginsh ps指定：useradd-s/ usermod,InteractiveBashBash

/bin/bashwindowsCRLFshellForksub-shellsub-shellbraceexpansion（花括号扩展tildeexpansion（波浪线扩展parameter,variableexpansion（变量扩展arithmeticexpansion（算术扩展commandsubstitution（命令替换wordsplitting（词的拆分pathnameexpansion（路径名扩展/etc/vimrc或~/.vimrcsyntaxon"setnumber显示行数setshiftwidth=4四格缩进settabstop=4setexpandtab "tab转spacesetbg=light "背景为亮色set "color "变量定义 变量引用 ––$name${name}``command$(command#例ls)date)cat) n1,2...n, $HISTTIMEFORMAT exportname=value;bashname=value​cnt=i+jcnt=$((i+jlet, –*manbash[ARITHMETICherebcechoecho"scale=3;10/3"|bcscale10/3 ##&&与for,break,if...if$0[[-n$str$str[[-z$str [[$str1==$str2[[$str1 $str2[[-b$file[[-r$file[[-c$file[[-s$file[[-d$file[[-w$file[[-e$file[[-x$file[[-f$file[[-p$file更详细内容manbash[CONDITIONALif...elseifexpression; elif……

if[[-f/etc/SuSE-release]];thenechoSUSEOSelif[[-f/etc/slackware-version]];thenechoSlackwareOSecho“Redhat检查$?000ififgrep-q“^admin:”/etc/passwdechoecho“not&&检查$?000grep-q“^admin:”/etc/passwd&&echo echo“not[[-z$logdir]]&&logdir=/tmp/cd/data/backup.d||exit1##case$varinStatments1;;default

readanswercase$answerinechoyes;;echonoechounknown*?[]|A|BAcase$answerinecho"Answerisecho"Answerisecho

case$answerinecho"Answerisecho"Answerisecho

whileexpression;dountilexpression;do

while((i<=100));iechosum:for$varinvar1var2

#forfilein$(ls-d/data*)if[[-h$file]];

echo“[symlink]STDIN(0),STDOUT(1),STDERRechoxxx>fileechoxxx1>filereadline<>调用 需要先定义后调用。名字＋参参数 $1,$2...$#,返回值 标准输退出状态 return$num；或最后一个命令的退出状#define{…}

#example{local((sum=$1+$2}

echocnt=$(add