script question 4

[extremedatos]

hi all,

i would like to know if there's any way i can run a script step by step?

thanks

 

[KenCunningham]

Maybe put a read between each step so that processing is continued once return is pressed.

The internet - allowing those who don't know what they're talking about to have their say.

 

[feherke]

Hi

If you want to debug a Bash script, there is no step-by-step execution.

If you want to know which lines are executed, you can put [tt]set -o xtrace[/tt] at the beginning of your script. If you set [tt]PS4='$LINENO+ '[/tt], then the line number will be also displayed.


Feherke.

http://free.rootshell.be/~feherke/

 

[extremedatos]

Nice thanks to all, one more question please,,,,
how can i execute it with out really running the script?
like in a test mode.. the problem is i have some scripts on a server and i want to run them but i don't want to make any of the changes that the script dose.

thanks!!!!!!

 

[KenCunningham]

Perhaps replace all actions with an echo to indicate which action would be taking place if run properly?

The internet - allowing those who don't know what they're talking about to have their say.

 

[SamBones]

Bash has an option to read and parse each line in a script, but not actually run it. This is for checking syntax.

From "[tt]man bash[/tt]"...

set [--abefhkmnptuvxBCHP] [-o option] [arg ...]
    <<<edited>>>
    Options, if specified, have  the  following  meanings:
    -n   Read commands but do not execute them.  This may be used
         to check a shell script  for  syntax  errors.   This  is
         ignored by interactive shells.

So a "[tt]set -n[/tt]" early in the script should do. Or, make your first line of your script like this...

#!/bin/bash -n

Also turning on "[tt]-x[/tt]" and "[tt]-v[/tt]" can add a lot of debug information.

 

[KenCunningham]

Nice one Sam, I wasn't aware of that but it looks useful.

The internet - allowing those who don't know what they're talking about to have their say.

 

[SamBones]

It's also a wonderful practical joke. Just adding a small and hardly noticeable "-n" to the she-bang line of someone's script can make them almost go insane.