Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"
 
PerlMonks  

Re: how to invoke unix commands in perl

by stefan k (Curate)
on Feb 08, 2001 at 20:22 UTC ( #57200=note: print w/replies, xml ) Need Help??


in reply to how to invoke unix commands in perl

There are several ways to invoke a programm. One of the main differences is in the returning value.
  • system("wc -l");
    Will call the given command and return the return value of that command. This is usually not what you want, because most of the times wc -l will mean that you want to get the number of lines back from that call and not if that call was successful or not.
  • $nol = `wc -l`
    The backticks call the command and return it's output into the variable (here $nol. In this case this will be what you want.
  • Another way of doing this is to use
    $nol = qx/wc -l/;
    (mnemonic: qx quote execute). I think is just the same as the backquotes (at least I don't know any difference)
  • Of course there are other ways (exec,fork) that behave different with respect to processes, but I don't know much about this
Hope this helps...

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://57200]
help
Chatterbox?
[1nickt]: Petroza to answer your question, no, no special permission is needed to post a question.
[LanX]: did you spam before? :)
LanX has to go/
[ambrus]: I hope we didn't mess up the spam filter rules again.
[ambrus]: Our spam filter rules disallow links to certain domains, and some suspicious pharses that have appeared in previous spam advertising cheap online whatevers.
[LanX]: some servers were lagging today, so I suppose the root cause
[LanX]: ambrus no recent patches
[Petroza]: no i haven't posted anything before. It was a more or less long question with a specific issue. I did post a title and the links i added where only part of the element i was searching within the code (so no purpose other than the question itself).
[1nickt]: Petroza can you go back in your browser to the preview screen, redact the links, and try to submit again?
[LanX]: copy and paste the text into your Petroza's scratchpad please

How do I use this? | Other CB clients
Other Users?
Others contemplating the Monastery: (10)
As of 2017-10-17 15:21 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    My fridge is mostly full of:

















    Results (233 votes). Check out past polls.

    Notices?