Hi Manfred,
On Sun, Mar 4, 2012 at 8:56 AM, Manfred Lotz <manfred.l...@arcor.de> wrote:
> Hi there,
> I've got a strange problem with $_. It seems I do not understand
> something which might be basic. Anyway, here is a minimal example.
>
> #! /usr/bin/perl
>
> use strict;
> use warnings;
> use 5.010;
>
> sub sub1 {
> my $cmd = shift;
>
> print "Sub3: Issuing [$cmd]\n";
> open my $fh, '-|', "$cmd 2>&1" or die "open: $!";
> while ( <$fh> ) { print; }
> close $fh;
> return $? >> 8;
> }
>
> sub sub2 {
> my $cmd = shift;
>
> say "\nSub1 $cmd";
> return 1;
> }
>
>
> my @cmds = ( "uname -a", "date");
>
> Please use a lexical variable for your foreach(s) loop:
> foreach ( @cmds ) { say sub1($_); };
> foreach ( @cmds ) { say sub2($_); };
>
like this:
foreach my $value1 ( @cmds ) { say sub1($value1); };
foreach my $value2 ( @cmds ) { say sub2($value2); };
>
> Running this gives:
>
> Sub3: Issuing [uname -a]
> Linux hogwart 3.0.0-14-generic-pae #23~lucid1-Ubuntu SMP Thu Dec 8
> 15:03:12 UTC 2011 i686 GNU/Linux 0
> Sub3: Issuing [date]
> Sun Mar 4 08:54:18 CET 2012
> 0
> Use of uninitialized value $cmd in concatenation (.) or string
> at ./foreach1.pl line 20.
>
> Sub1
> 1
> Use of uninitialized value $cmd in concatenation (.) or string
> at ./foreach1.pl line 20.
>
> Sub1
> 1
>
>
> What am I doing wrong here?
>
> Nothing really, but after your first foreach loop, there is
**nothing** left in your array @cmds for the second foreach loop to iterate
over.
> --
> Manfred
>
>
>
>
>
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>
--
Tim
