topic Re: Perl/CGI running external commands in Operating System - Linux

Perl/CGI running external commands

Kalin Evtimov — Mon, 31 Oct 2005 06:39:10 GMT

Hi!

I am using Perl for extracting and parsing data from my server. I habe a *.cgi, which runs those lines when called:

system ("/usr/bin/perl /opt/webmin-1.230/vimod/load/testreverse.pl");

system ("/usr/local/bin/pl -png /opt/webmin-1.230/vimod/load/$script_name");
---------------------------------------------

The first call doesn't work and I wonder why? The Perl-Script has W,R,X-Rights. If I call it from the shell, there is no problem.

The second is running correctly.
Can anybody help?

Thank you!

Re: Perl/CGI running external commands

Orhan Biyiklioglu — Mon, 31 Oct 2005 06:49:06 GMT

How do you run it from the command line? Are you sure your perl binary is under /usr/bin

Re: Perl/CGI running external commands

Kalin Evtimov — Mon, 31 Oct 2005 07:02:30 GMT

I call ot with:

$/dir/script>perl tralala.pl

Perl is in /opt/perl5/bin, but when I changed it it didn't work again.

Re: Perl/CGI running external commands

Zeev Schultz — Mon, 31 Oct 2005 08:13:08 GMT

Tried "-w" for perl to see what it complains if at all? I'd also try to separate command and agrument, like "perl" "...".system() does fork I think and calls a shell so it may be some shell thing that doesn't work.See this one also:

http://www.perl.com/doc/FAQs/cgi/idiots-guide.html

Re: Perl/CGI running external commands

Daavid Turnbull — Tue, 01 Nov 2005 20:42:34 GMT

Out of curiostiy what is the CGI language are you using? (I am thinking that you might be better off writing the whole think in perl.)

Presuming you have as the first line of your script:

#! /usr/bin/perl

why would you not run:

system("/opt/webmin-1.230/vimod/load/testreverse.pl");

??

Re: Perl/CGI running external commands

Kalin Evtimov — Mon, 07 Nov 2005 03:09:27 GMT

It is perl..
There should not be any difference..anyway I may try this.

Re: Perl/CGI running external commands

Muthukumar_5 — Mon, 07 Nov 2005 03:22:10 GMT

You have to check with perl binary location. If it is in PATH Variable then you may not need to give full path.

Get perl path as,

$PERL=`which perl`
system("$PERL <script>");

It will work.

~regards

Re: Perl/CGI running external commands

Kalin Evtimov — Mon, 07 Nov 2005 03:43:07 GMT

Sorry, but it doesn't work. Perl is behaving really strange on this machine. Commeing a line in the source changes the script behaviour completly..It is the system-call in the attachment. The script should create 4 files. There is a system call deleting all old files, before creating the new ones. When this line is not commented, the script creates only one file. If I remove the line, it creats 4 files, as it must be..
All this means, that I don't know where am I stuck- perl programming or system administration :(

Re: Perl/CGI running external commands

Daavid Turnbull — Mon, 07 Nov 2005 05:32:23 GMT

The system call to remove the files can be done with the unlink() function directly from Perl.

That is tis only system call I can see - Am I missing something?

Re: Perl/CGI running external commands

Muthukumar_5 — Mon, 07 Nov 2005 05:48:48 GMT

It is your scripting problem :)

sub create_data_files {

system ("rm -f /opt/webmin-1.230/vimod/load/*.tmp");

}

&create_data_files("hour");
&create_data_files("day");
&create_data_files("week");
&create_data_files("month");

Every execution will delete all .tmp files. It will keep only "month" file only at last. Do you want to delete all old files?

Remove system ("rm -f /opt/webmin-1.230/vimod/load/*.tmp"); from sub create_data_files and put it infront of,

system ("rm -f /opt/webmin-1.230/vimod/load/*.tmp");
&create_data_files("hour");
&create_data_files("day");
&create_data_files("week");
&create_data_files("month");

It will work now. Refer attachment for fresh.

~regards