return code help

learnbash · February 10, 2009, 11:23am

Hello folks,

I have a question that if i type ls command and type echo $? it always show "0", how i could do this change that when i type ls it will show me 1, actually i want to change the return code of commands from 0 to 1.

Thanks
Bash

vgersh99 · February 10, 2009, 11:25am

bash-2.05$ ls foo
foo: No such file or directory
bash-2.05$ echo $?
2

learnbash · February 10, 2009, 11:36am

Hello,

thanks for your reply, but i want to replace only true output to "1", ls always return "0" how could i replace only ls command output to "1".

Thanks,
Bash

vgersh99 · February 10, 2009, 11:47am

no, 'ls' does not always return '0'.
here's what 'man ls' yields:

EXIT STATUS
     0     All information was written successfully.

     >0    An error occurred.

just curious, why would you want to return a non-zero value when 'ls' was successful?

learnbash · February 10, 2009, 11:59am

vgersh99:

no, 'ls' does not always return '0'.
here's what 'man ls' yields:
EXIT STATUS
   0     All information was written successfully.

   >0    An error occurred.
just curious, why would you want to return a non-zero value when 'ls' was successful?

Hello,

Thanks once again for quick reply, i understand what you are saying actually i want to make all commands return code to "1", ls is just an example.

Thanks.
Bash

pludi · February 10, 2009, 12:25pm

Why? It's common practice in UNIX for programs to return 0 on successful exit (yes, I know it's different to C, where non-zero indicates success). If you want to change that, have fun updating and recompiling almost every util and shell for your OS.