Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW
 
PerlMonks  

capture output from another program

by BioLion (Curate)
on Jun 02, 2009 at 17:40 UTC ( #767696=perlquestion: print w/ replies, xml ) Need Help??
BioLion has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks,

I have written a perl wrapper to manage commandline excecution of another (non-perl, commercial, which i can't modify myself...) program using Parallel::ForkManager (thanks for the tutorial!).

The program being excecuted program spits out a lot of info to the terminal which i would like to capture, and keep the info from each child separate to use later.

Capturing from *my* programs is fine (IO::Capture), but from the (linux) terminal, I don't know where to start.

Can I intercept output from any child process? Even if the output is coming from an external program?

Any thoughts would be gratefully received.

Just a something something...

Comment on capture output from another program
Re: capture output from another program
by xdg (Monsignor) on Jun 02, 2009 at 17:54 UTC

    You want Capture::Tiny. It can do both perl and external programs.

    -xdg

    Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

      Thanks - I have also had some success with IPC::Run

      Just a something something...

        That works too, though I'm partial to IPC::Run3. I wrote Capture::Tiny so I could use just one thing consistently instead of one thing to capture Perl and another to capture from external programs, and another to capture from XS and so on. For example, IO::Capture uses ties, so it only captures from pure perl. Output from XS or from system won't be captured.

        Capture::Tiny uses one syntax to capture whatever you want:

        use Capture::Tiny 'capture'; my ($out, $err) = capture { print "Capture this"; might_print_via_XS(); system($^X, '-e', 'print "Capture me too\n"; warn "And this"'); };

        That just seemed far more convenient to me.

        If anyone is interested, I gave a talk on "How Not to Capture Output in Perl", which shows some of the difficulties/limitations using other things to capture output.

        And while the talk doesn't mention it, Capture::Tiny even handles utf8 output:

        use Capture::Tiny 'capture'; binmode(*STDOUT, ':utf8'); my $out = capture { print "Hi! \x{263a}\n"; system($^X, '-e', 'print "Hi! \x{263a}\n"'); };

        -xdg

        Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: perlquestion [id://767696]
Approved by ikegami
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others about the Monastery: (7)
As of 2014-07-31 08:41 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (247 votes), past polls