linux shell script 循环语句

1. while 语句

1. while do done格式while [condition]do    program blockdone

例子：

    #/bin/bash    echo "====while test ===="    i=0    cat ./1.c | while read line #该while相当于依次将1.c文件中每行字符串取出，并赋值给line变量    do    echo $line    cd $line    git log | grep "Sat Oct 10"    cd -    done

    #/bin/bash    echo "====while test ===="    i=0    cat ./git.log | while read line    do    len=${#line} #该指令是获取line字符串的长度    len_1=$len-4    line_1=${line:0:$len_1} #该指令是从line字符串的第0个字符开始取$len_1个字符组成的字符串赋值给line_1    echo $line_1    repo sync $line_1    done

2. until语句

2. until do done格式:until [condition]doprogram blockdone

3. for语句

3. for do done格式:for variable_name in content1 content2 content3 ...doprogram blockdone

例子：

fl=$(ls "$dir")for name in $fl #该for相当于将fl字符串中以空格为间隔依次取出，并赋值给name变量do        program blockdone