[SOLVED] A brief shell script.The result is not what I wanted.

mirage1993 · 03-07-2014, 08:11 AM

Quote:

Originally Posted by suicidaleggroll

You can return any number between 0-255

oh ...yes ...we often use 0 and 1.

rtmistler · 03-07-2014, 08:12 AM

You can return any value from 0-255; I don't think you can return negative numbers, nor numbers larger than 255.

mirage1993 · 03-08-2014, 03:05 AM

Quote:

Originally Posted by rtmistler

You can return any value from 0-255; I don't think you can return negative numbers, nor numbers larger than 255.

if I return a negative number,it may display error information.But if I return 777,it would return 9 in fact .Because the Exit code is limited to 8 bits,so it's 00001001 rather than 1100001001...

szboardstretcher · 03-08-2014, 12:33 PM

Here is some proof of my grep claims.

Code:

## 'found' exit status
# grep -i 'end' text.txt
bend over linux
# echo $?
0

## 'not found' exit status
# grep -i 'asdf' text.txt 
# echo $?
1

## 'error' exit status
# grep -i82934rj 'enddasdf' text.txt 
grep: invalid option -- 'j'
Usage: grep [OPTION]... PATTERN [FILE]...
Try 'grep --help' for more information.
# echo $?
2