LinuxQuestions.org - [SOLVED] this script's returned value is 120,why??

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- - this script's returned value is 120,why?? (https://www.linuxquestions.org/questions/linux-newbie-8/this-scripts-returned-value-is-120-why-4175495918/)

this script's returned value is 120,why??

I creat a file and edit it .

Code:

#!/bin/bash



exit 888

then,

Code:

[root@localhost]# ./script.sh 

[root@localhost]# echo $?

120

I want to know why the returned value is not 888,thanks.

Hi there,

Quote:

Originally Posted by mirage1993 (Post 5123101)

I creat a file and edit it .

Code:

#!/bin/bash



exit 888

then,

Code:

[root@localhost scripts]# ./script.sh 

[root@localhost scripts]# echo $?

120

I want to know why the returned value is not 888,thanks.

that's because return values are limited to 8 bits for historical reasons. So the given return value of 888 is truncated, the high-order bits are dropped:

Code:

  888 (dec) = 0x0378

 strip high byte and convert back:

  0x78 = 120 (dec)

There you go.

[X] Doc CPU

Quote:

Originally Posted by Doc CPU (Post 5123122)

Code:

  888 (dec) = 0x0378

 strip high byte and convert back:

  0x78 = 120 (dec)

great!!!thank you sooo much!!
@Doc CPU