http://www.perlmonks.org?node_id=682636


in reply to Running a script iteratively.

I would use cron for this, but here is a non-robust solution.

Update: For the reasons outlined by Fletch below, don't do this... 

#!/usr/bin/perl

use strict;
use warnings;

while(1){
   `get_value.pl`;
   sleep 120;
}

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Re^2: Running a script iteratively.
by Fletch (Bishop) on Apr 24, 2008 at 14:48 UTC

    Eeeew. Backticks in void context? Use the right tool for the job.

    The cake is a lie.
    The cake is a lie.
    The cake is a lie.

[reply]
      I said it was non-robust. Perhaps I should have described it as "icky" instead?
[reply]

        Robustness aside (as it suffers from the same lack of error checking the other proffered version below with system has :), it doesn't express the intent behind the code correctly. Backticks are for capturing the output from an external program; system is for starting an external program who's output you don't care about.

        It's like using map in void context to iterate over a list in place of for; yes it "works", but if the line of code is not building a new list of values from an existing list then you're using the wrong "phrasing" (by which I mean 'not the clearest') to express your intent (map is for expressing transformation, for is for expressing iteration).

        (And I won't go into the "PERL scripts" I've seen that basically consisted of a shebang line and then every line was shell commands in backticks . . . *shudder* :)

        Update: Tweaked for perldoc link somewhere more relevant per prodding from kyle.

        The cake is a lie.
        The cake is a lie.
        The cake is a lie.

[reply]
      TIMTOWTDI
[reply]

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