（十三）、向shell脚本中传参

一、向脚本中传递位置参数

向脚本中传递参数的数目理论上可以无数多，但是只有前9个能被访问，使用shift可以改变此限制

$0	$1	$2	$3	$4	$5	$6	$7	$8	$9
脚本名字	first	second	third	fourth	fifth	sixth	seventh	eighth	ninth

 1 $ vim param
 2
 3 #!/bin/sh
 4 echo  "This is the script     name                       : $0"
 5 echo  "This is the first       param                      : $1"
 6 echo  "This is the second   param                      : $2"
 7 echo  "This is the third       param                      : $3"
 8 echo  "This is the fourth     param                      : $4"
 9 echo  "This is the fifth        param                      : $5"
10 echo  "This is the sixth       param                      : $6"
11 echo  "This is the seventh   param                      : $7"
12 echo  "This is the eighth     param                      : $8"
13 echo  "This is the ninth       param                      : $9"
$ chmod u+x param 
$ ./param Did You See The Full Moon

This is the script     name                       : Did
This is the first       param                      : You
This is the second   param                      : See
This is the third       param                      : The
This is the fourth     param                      : Full
This is the fifth        param                      : Moon
This is the sixth       param                      : 
This is the seventh   param                      : 
This is the eighth     param                      :
This is the ninth       param                      : 

二、向系统命令中传递参数

 1 $ vim findfile
 2 #！/bin/sh
 3 # findfile
 4 find / -name $1 -print   #find $1 in /
 5
 6 $ chmod u+x findfile
 7 $ findfile passwd
 8 /etc/passwd
 9 /etc/uucp/passwd
10 /usr/bin/passwd

三、特定变量参数

$#	传递到脚本的参数个数
$*	以一个单字符串显示所有向脚本传递的参数
$$	脚本运行的当前进程ID号
$!	后台运行的最后一个进程的ID号
$@	与$#相同，但是 使用时加双引号
$-	显示shell使用的当前选项
$?	显示最后命令的退出状态

$ vim param

#!/bin/sh
echo  "This is the script     name                       : $0"
echo  "This is the first       param                      : $1"
echo  "This is the second   param                      : $2"
echo  "This is the third       param                      : $3"
echo  "This is the fourth     param                      : $4"
echo  "This is the fifth        param                      : $5"
echo  "This is the sixth       param                      : $6"
echo  "This is the seventh   param                      : $7"
echo  "This is the eighth     param                      : $8"
echo  "This is the ninth       param                      : $9"
echo  "The number of arguments  passed            : $#"
echo  "show all arguments                                 :  $*"
echo  "did my script go with any errors                : $?"
$ chmod u+x param
$ ./param Did You See The Full Moon
This is the script     name                       : Did
This is the first       param                      : You
This is the second   param                      : See
This is the third       param                      : The
This is the fourth     param                      : Full
This is the fifth        param                      : Moon
This is the sixth       param                      :
This is the seventh   param                      :
This is the eighth     param                      :
This is the ninth       param
The number of arguments  passed            : 6
show all arguments                                 :  Did You See The Full Moon
did my script go with any errors                : 0