topic Re: Cannot run command from CGI in Operating System - HP-UX

Cannot run command from CGI

Kalin Evtimov — Fri, 19 May 2006 02:35:25 GMT

HI!
In a cgi-script I am trying to run

system ("/bin/top -d1 > /tmp/top.out");

this doesn't write anything to the file. Why?

Greetings!
Kalin

Re: Cannot run command from CGI

Warren_9 — Fri, 19 May 2006 02:37:50 GMT

hi,

try "top -d 1 -f /tmp/top.out"

GOOD LUCK!!

Re: Cannot run command from CGI

Kalin Evtimov — Fri, 19 May 2006 02:43:44 GMT

It doesn't seem to ba e syntax problem, because from the command line they both work.

Re: Cannot run command from CGI

Peter Godron — Fri, 19 May 2006 03:04:23 GMT

Kalin,
To eliminate any problem with file creation:
system("echo test > /tmp/top.out");
if that works at least you have narrowed the problem to the top command.
Please Update

Re: Cannot run command from CGI

Kalin Evtimov — Fri, 19 May 2006 03:10:14 GMT

system("echo test > /tmp/top.out");

That worked!

What could be wrong with the top command, this is a bit difficult for me..:(

Re: Cannot run command from CGI

Steve Lewis — Fri, 19 May 2006 03:16:14 GMT

No. You must use -f if you want to send the output of top to a file, or else it will not be readable.

You have not writted how your CGI system command is executed. Is it from perl? from awk? from ruby? from python? from php?

the top command is definitely
"/bin/top -d 1 -f /tmp/top.out"

but if another user has already created that file, length zero, then your www user will not be able to overwrite it.

Check the output file permissions.

Re: Cannot run command from CGI

Kalin Evtimov — Fri, 19 May 2006 03:19:18 GMT

I am using the web-server from the Webmin-tool for UNIX Administration.
Thank you for the advice!

Re: Cannot run command from CGI

Peter Godron — Fri, 19 May 2006 03:22:04 GMT

Kalin,
so the re-direct works.
No try and capture any error messages:
system("/usr/bin/top -d1 > /tmp/top.out 2>&1");

Re: Cannot run command from CGI

Kalin Evtimov — Fri, 19 May 2006 03:24:53 GMT

Thank you for your idea Peter!
Steve's suggestion worked for me, I had to delete the top.out file once, so that it is could be created again from the webserver-user.

Greetings!
Kalin