Running shell script through perl

tucs_123 · 03-17-2009, 07:03 AM

Hi,

Can any one tell me how to run a shell script through perl with example?

Telemachos · 03-17-2009, 07:20 AM

Quote:

Originally Posted by tucs_123

Can any one tell me how to run a shell script through perl with example?

It's a bad idea, in my experience. It's better either to run the shell script as a shell script or to rewrite it in Perl. (That means more than simply passing commands to the shell via Perl. It means writing it to Perl's strengths and weaknesses.)

Can you show the script and say a bit more about why you want to do it this way?

Sergei Steshenko · 03-17-2009, 07:34 AM

Quote:

Originally Posted by Telemachos

It's a bad idea, in my experience. It's better either to run the shell script as a shell script or to rewrite it in Perl. (That means more than simply passing commands to the shell via Perl. It means writing it to Perl's strengths and weaknesses.)

Can you show the script and say a bit more about why you want to do it this way?

Maybe the OP just meant running any executable through 'system' ?

Frullet · 03-17-2009, 07:45 AM

system ("./bashscript");

But as before, it is best to rewrite the shell script in perl, or just stick to the shell script itself.

Sergei Steshenko · 03-17-2009, 07:55 AM

Quote:

Originally Posted by Frullet

system ("./bashscript");

But as before, it is best to rewrite the shell script in perl, or just stick to the shell script itself.

If the shell script works, why rewrite ?

If something new is to be written, why write it in shell ?

ghostdog74 · 03-17-2009, 08:12 AM

Quote:

Originally Posted by Sergei Steshenko

If the shell script works, why rewrite ?

not pertaining to this thread. Few reasons (not just shell scripts) i can think of.
1) the script works, but take up too much resources. therefore needs to rewrite to make it better.
2) company is revamping their scripting standards. scripts will be written in one particular language for a "uniform" environment. They don't want shell, perl, ruby etc scripts all lying around.
3) the script works, but due to new business processes and requirement, it has to be rewritten to cater for these new processes.

Telemachos · 03-17-2009, 08:20 AM

Quote:

Originally Posted by Sergei Steshenko

Maybe the OP just meant running any executable through 'system' ?

You may be right, but the OP asked how to do this for a 'shell script', and by that I took him to mean a script for Bash or Ksh or whatever.

One thing to add to Ghostdog's reasons: a well-written Perl program should be more portable than a shell script (which will often rely on particular implementations of sed, grep and company).

Sergei Steshenko · 03-17-2009, 08:36 AM

Quote:

Originally Posted by Telemachos

...
One thing to add to Ghostdog's reasons: a well-written Perl program should be more portable than a shell script (which will often rely on particular implementations of sed, grep and company).

I agree with that - whenever I try to write something in shell in an hour I'm asking myself "why haven't I written this in Perl ?".

I do, however, in certain cases generate shell scripts from my Perl scripts, but these shell scripts are just plain sequential commands.

The point is that contents of these scripts are not known until some pretty complex processing is done in Perl; after that the shell scripts are kind of "exported intelligence" from Perl, and can be used separately.

Kunsheng · 03-19-2009, 07:43 PM

Try this:

execlp("/bin/bash", "/bin/bash","[Your script]","-C", (char*)NULL);