linux学习之shell脚本 ------- 脚本参数传递

[本文是自己学习所做笔记，欢迎转载，但请注明出处：http://blog.csdn.net/jesson20121020]

今天再来看一下如何向shell脚本传递参数，需要掌握两个命令，一个是 shift命令，另一个是getopts。

脚本参数传递

　　shift命令

　　　用法：

　　　　shift n 每次将参数位置向左偏移n位

　　　假如我们要实现统计多个文件的总行数，就可以用到这个shift命令了，如下:

opt2.sh

#!/bin/bash
#op2  static files total lines;
staticlines(){
   echo "static:`basename $0` filenames"
   exit
}
totalline=0
if [ $# -lt 2 ]
then
    staticlines
fi
while [ $# -ne 0 ]
do
    line=`cat $1 | wc -l`
    echo "$1:${line}"
    totalline=$[ $totalline+$line ]
    shift
done
echo "-------------------------------------"
echo "totalline:${totalline}"

　　　给予可执行权限，执行：

[email protected]:~/develop/worksapce/shell_workspace$ chmod a+rx opt2.sh
[email protected]:~/develop/worksapce/shell_workspace$ ./opt2.sh
static:opt2.sh filenames
[email protected]:~/develop/worksapce/shell_workspace$ ./opt2.sh lsout.txt
static:opt2.sh filenames
[email protected]:~/develop/worksapce/shell_workspace$ ./opt2.sh lsout.txt name.txt
lsout.txt:18
name.txt:4
-------------------------------------
totalline:22
[email protected]:~/develop/worksapce/shell_workspace$ ./opt2.sh lsout.txt name.txt while_test1.sh
lsout.txt:18
name.txt:4
while_test1.sh:6
-------------------------------------
totalline:28

　　　通过shift 命令，我们可以很容易地实现统计log等信息。

　　getopts命令

　　　该命令可以获得多个命令行参数。

　　　还是一个脚本来分析getopts的用法

optsget.sh

#!/bin/bash
#optsget
ALL=false
HELP=false
FILE=false
VERBOSE=false
while getopts ahfvc: OPTION
do
     case $OPTION in
     a)
         ALL=true
         echo "ALL is $ALL"
         ;;
     h)
         HELP=true
         echo "HELP is $HELP"
         ;;
     f)
         FILE=true
         echo "FILE is $FILE"
         ;;
     v)
         VERBOSE=true
         echo "VERBOSE is $VERBOSE"
         ;;
     c)
         c=$OPTARG
         echo "c valuse is $c"
         ;;
     \?)
         echo "`basename $0` -[a h f v] -[c value]"
         ;;
      esac
done

　　　给予可执行权限，执行结果如下：

[email protected]:~/develop/worksapce/shell_workspace$ ./optsget.sh -a
ALL is true
[email protected]:~/develop/worksapce/shell_workspace$ ./optsget.sh -a -f
ALL is true
FILE is true
[email protected]:~/develop/worksapce/shell_workspace$ ./optsget.sh -a -f -h
ALL is true
FILE is true
HELP is true
[email protected]:~/develop/worksapce/shell_workspace$ ./optsget.sh -a -f -h -v
ALL is true
FILE is true
HELP is true
VERBOSE is true
[email protected]:~/develop/worksapce/shell_workspace$ ./optsget.sh -a -f -c
ALL is true
FILE is true
./optsget.sh: 选项需要一个参数 -- c
optsget.sh -[a h f v] -[c value]
[email protected]:~/develop/worksapce/shell_workspace$ ./optsget.sh -a -f -c jesson
ALL is true
FILE is true
c valuse is jesson

　　不难看出，可以通过getopts命令取得多个参数，而且还可以为每个参数指定值，在需要指定值的参数后加：即可。