using system() and putting results into an array

lasagnashoe has asked for the wisdom of the Perl Monks concerning the following question:

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Re: using system() and putting results into an array by targetsmart (Curate) on May 21, 2009 at 13:14 UTC
use backticks `` see qx also Vivek -- In accordance with the prarabdha of each, the One whose function it is to ordain makes each to act. What will not happen will never happen, whatever effort one may put forth. And what will happen will not fail to happen, however much one may seek to prevent it. This is certain. The part of wisdom therefore is to stay quiet.	[reply]
Re: using system() and putting results into an array by jwkrahn (Abbot) on May 21, 2009 at 13:43 UTC
`open my $PIPE, '-\|', 'diff', $file1, $file2 or die "Cannot open pipe f +rom 'diff' $!"; my @diffs = map { s/^[><]//; $_ } <$PIPE>; close $PIPE or warn $! ? "Error closing 'diff' pipe: $!" : "Exit status $? from 'diff'";` [download]	[reply] [d/l]
Re: using system() and putting results into an array by johngg (Canon) on May 21, 2009 at 13:57 UTC
You can open a filehandle on a piped command and you can also use Perl's built-in grep to do what `sed` does in your code. Here's an example applied to a couple of nonsense files. `$ diff dddd eeee 2c2 < werfef --- > werftef 7c7 < esdd --- > es4dd $ $ diff dddd eeee \| sed -re '/^[><]/d' 2c2 --- 7c7 --- $` [download] The script to do the same job. `use strict; use warnings; my $file1 = q{dddd}; my $file2 = q{eeee}; my @diffs = do{ open my $diffFH, q{-\|}, qq{diff $file1 $file2} or die qq{fork: diff $file1 $file2: $!\n}; grep ! m{^[><]}, <$diffFH>; }; print for @diffs;` [download] The output, which is identical to that produced by `diff` and `sed` on the comand line. $ ./spw765446 2c2 --- 7c7 --- $ [download] I hope this is useful. Cheers, JohnGG	[reply] [d/l] [select]
Re: using system() and putting results into an array by Bloodnok (Vicar) on May 21, 2009 at 13:32 UTC
As targetsmart has already correctly pointed out, the backtick/qx operators are your friend in this case - system does nothing with STDIN or STDERR and returns nothing other than the error code and the signal number from the sub-process. A user level that continues to overstate my experience :-))	[reply]
Re: using system() and putting results into an array by tokpela (Chaplain) on May 22, 2009 at 08:18 UTC
You might also want to look at String::Diff so that you don't even need to run a system call.	[reply]
Re^2: using system() and putting results into an array by lasagnashoe (Initiate) on May 22, 2009 at 13:35 UTC
Thanks everyone for your help! :)	[reply]