1)for语句 for var in word-list command-I done for count in 1 2 3 echo SI for or va 2) while语句 while(expression) done #greeting=hello world hile test Si-le 100: do case Si in 0)echo“***率***少>fle$i *)echo Si>fileS i= expr Si+ 1 例 d命令的实现 case S# in 1)cat>>SI 2)cat<$l>$2 *)echo"usage: append [from] to #chmod +x myappend #myappend filel file2 18函数 functionname() command-list usage1）for 语句 for var in word-list do command-list done for count in 1 2 3 do echo $I done for var do 2)while 语句 while (expression) do command-list done #greeting=’hello world’ i = 1 while test $i –le 100 ; do case $i in *0) echo “**********”>file$i ;; *) echo $i > file$i ;; esac i = ` expr $i + 1 ` done 例：append 命令的实现： case $# in 1) cat >> $1 ;; 2) cat < $1>> $2 ;; *) echo ‘usage: append [from] to ’;; esac #chmod +x myappend #myappend file1 file2 1.8 函数 functionname( ) { command-list } usage()