Linux下的shell编程入门

Linux shell shell shell Shell C Shell Linux Linux shell 1 date, bin #Program date #usageto ::show the date in this way ( ) echo Mr.$USER,Today is: echo date +%B%d%A echo Whish you a lucky day ! 2 chmod +x date ls shell . [beichen@localhost bin]$ date Mr.beichen,Today is: January 13 Friday Whish you a lucky day ! bin [beichen@localhost bin]$ PATH=$PATH:$HOME/bin ( $HOME /home/beichen, bin ) date shell : [beichen@localhost /]$ bash date Mr.beichen,Today is: January 13 Friday Whish you a lucky day ! chmod +x date date Linux [beichen@localhost /]$ .date Mr.beichen,Today is: January 13 Friday Whish you a lucky day ! date . shell shell ls shell Shell 1 $N N 1 $1. C Linux 0 0 1 $0 $1 2 $0 $1 $0 $# ---- $? ---- shell shell 0 0 $* ---- P1: echo Program name is $0 echo There are totally $# parameters passed to this program echo The last is $? echo The parameters are $* [beichen@localhost bin]$ P1 this is a test program // 5 Program name is /home/beichen/bin/P1 // There are totally 5 parameters passed to this program // The last is 0 // The parameters are this is a test program // del #name: del #author: liangnian #this program to compress a file to the dustbin if test $# -eq 0 then echo Please specify a file! else gzip $1 // mv $1.gz $HOME/dustbin // echo File $1 is deleted ! fi test shell ?D?D (test) shell if ( ) test shell shell 1 NULL( bash ) = != -n -z 2 test >? -eq -ge -le -ne -gt -lt 3 ! -a (and) -o (or) 4 test -d -f -L -r -s -w -x file1 ?Cnt(-ot) file2 1 2 ( ) shell for while until for for in do done for .gz #delete all file with extension of gz in the dustbin for I in $HOME/dustbin/*.gz do rm ?Cf $i echo $i has been deleted! done [beichen@localhost bin]$.f_rmgz /home/beichen/dustbin/nessus-4.0.0.2.tar.gz has been deleted! /home/beichen/dustbin/gftp-2.2.1.tar.gz has been deleted! While while do done while do done until until do done do done : #test until #add from 1 to 100 total=0 num=0 until test num ?Ceq 100 do total=`expr $total + $num` // , num=`expr $num+1` done echo The result is $total [beichen@localhost bin]$until The result is 5050! Shell if case If if 1 then elif 2 then elif 3 then .. else fi Linux if if fi elif else if elif Case case in 1| 2) :: 3| 4) :: 5| 6) :: *} :: esac case | case :: case $USER in beichen) Echo You are beichen! ;; liangnian) echo You are liangnian ; // echo Welcome! ;; // root) echo You are root!:echo Welcome! ;; // *) echo Who are you?$USER? ;; esac [liangnian@localhost bin]$ test You are liangnian Welcome! shell shell