Shell脚本学习之基本参数

Shell脚本学习笔记---基本参数解析

常见命令行参数意义

    菜鸟们总会被shell脚本中常见变量弄混淆，这些变量有$?, $#, $0, $@, $*

$?表示前一个命令的返回值，0表示正确，非0值表示错误

#test05.sh#!/bin/bash
sh test01.sh
if [ $? -ne 0 ]; then    echo "test01.sh excute failed!"else    echo "test01.sh excute right!"fi

#test01.sh#!/bin/basharray=(zl love ll forever)for((i=0;i<${#array[@]};i++)); do    printf "%s " ${array[$i]}doneprintf "\n"

[[e-mail] shell]$ sh test05.sh
zl love ll forever
test01.sh excute right!

$#表示命令行参数个数，相当于C语言中的argc

$0表示本脚本的名称

[[e-mail] shell]$ vim test03.sh#!/bin/bashecho $0

结果如下
 [[e-mail] shell]$ sh test03.sh                                                                                                       
test03.sh                                                                                                                                                                                                 

 所以$0参数还是很有用的，尤其在目录结构上，例如： 

#!/bin/bashcd `dirname $0`source ../conf.sh

$@和$*都表示命令行参数，二者存在细微的区别：

共同之处：

echo "begin:"for i in $@do    echo $idone;

result:
[[e-mail] shell]$ sh test05.sh zl love ll 1314                                                                                
begin:                                                                                                                                                                                                       
zl                                                                                                                                                                                                               
love                                                                                                                                                                                                           
ll                                                                                                                                                                                                               
1314                                                                                                                                                                                                        

echo "begin:"for i in $*do    echo $idone;

[[e-mail] shell]$ sh test05.sh zl love ll 1314                      
begin:                                                                                       
zl                                                                                           
love                                                                                         
ll                                                                                       
1314

不同之处：

for i in "$@"do    echo $idone;

result:
[[e-mail] shell]$ sh test05.sh zl love ll 1314                                                                                 
begin:                                                                                                                                                                                                         
zl                                                                                                                                                                                                                  
love                                                                                                                                                                                                             
ll                                                                                                                                                                                                                  
1314                                                                                                                                                                                                          

echo "begin:"for i in "$*"do    echo $idone;

[[e-mail] shell]$ sh test05.sh zl love ll 1314                                                                               
begin:                                                                                                                                                                                                      
zl love ll 1314