linux shell (四)shell编程

一、用户交互

1、命令行参数

$0：程序名

$1~$9：参数

当多余9个参数时： ${10} ${11}...${n}

2、参数个数：$#

3、最后一个参数：${!#} 或 last=$#;$last

4、全部参数

$*：把整行当成一个参数

$@：同一字符串中的多个对立单词

基本上使用$@

5、移动参数变量shift n(无n默认1)

#!/bin/bash
#descrip: test 
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/xiaolong.hou/bin:/usr/local/jdk1.7/bin:/usr/local/maven/bin:/usr/local/hadoop-1.2.1/bin

while [ -n "$1" ]
do
        echo $1
        shift
done

exit 0

 

 6、处理选项

#!/bin/bash
#descrip: test 
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/xiaolong.hou/bin:/usr/local/jdk1.7/bin:/usr/local/maven/bin:/usr/local/hadoop-1.2.1/bin

while [ -n "$1" ]
do
        case $1 in
        -a) echo "-a option";;
        -b) echo "-b option";;
        -c) echo "-c option";;
        *) echo $1" is not a option"
        esac
        shift
done

exit 0

 7、getopt命令的使用

getopt abc:d -abd -c test1 test2

result: -a -b -d -c test1 -- test2

脚本中使用set -- `getopt -q abc:d  "$@"`

#!/bin/bash
#descrip: test 
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/xiaolong.hou/bin:/usr/local/jdk1.7/bin:/usr/local/maven/bin:/usr/local/hadoop-1.2.1/bin

set -- `getopt ab:c "$@"`
while [ -n "$1" ]
do
        case $1 in
        -a) echo "-a option";;
        -b) echo "-b option -param "$2
            shift;;
        -c) echo "-c option";;
        --) shift;break;;
        *) echo $1" is not a option"
        esac
        shift
done

for p in $@
do
        echo "params $p"
done

exit 0

 getopts高级使用

#!/bin/bash
#descrip: test 
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/xiaolong.hou/bin:/usr/local/jdk1.7/bin:/usr/local/maven/bin:/usr/local/hadoop-1.2.1/bin

while getopts :ab:c opt
do
        case $opt in
        a) echo '-a option';;
        b) echo '-b option with param '$OPTARG;;
        c) echo '-c option';;
        *) echo 'unknown option '$opt
        esac
done

shift $[ $OPTIND - 1 ]

for p in $@
do
        echo "param: "$p
done
exit 0

 8、用户输入

read -n -t -p var_input

read -s 密码输入等用到

$REPLY变量将存放输入的值