set

tanjiyong138

set --  特性怎么用？

tanjiyong138

就是 控制  $1 $2 $3  你可以在任意位置用这个命令更改 位置参数

hejia0105

回答你：
a 脚本如下：
#!/bin/bash
echo $*
set -- o o p p i i
echo $*

调用：./a a b c
输入结果：
a b c
o o p p i i


把当前传入的参数改成-- 后面的参数。

tanjiyong138

set -- a b c d
count=$#
在函数内设置参数

briangao

set in shell script overrides to default value of position variables $1, $2, $3 ...

If you don't have set command in your shell script, $1 automatically takes the vaule of the first parameter you pasted to the shell script. $2 takes the second parameter and so on.

For example:

Your first script is script1.sh

1. 
   
2. #!/bin/sh
   
3. echo $1
   
4. echo $2
   

复制代码

When you run it as:  script1.sh start all , the shell will automatically assign $1=start and $2=all. The output of running this script is:
start
all

Your second script is script2.sh

1. 
   
2. #!/bin/sh
   
3. set `who -r`
   
4. echo $1
   
5. echo $2
   

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When you run it as:  script2.sh start all , the output will be:
.
run-level

This is because the output of who -r command is something like:
.       run-level 3  Aug 13 11:40     3      0  S

So now $1=. , $2=run-level, $3=3, $4=Aug, $5=13 ... and $1 is no longer start and $2 is no longer all any more.