Is there something that makes you unable to paste the actual text of the error message into your post? What does "It" refer to? What does "the preceding line" refer to? What exactly did you try, and what exactly was the full error message? Were you using the code as I posted it, or did you try something "based on" my post? What OS are you using?

If you could give more explicit information about the problem(s) you're having, you might get some useful help.

The error is not very descriptive but here it is

Too many arguments for open at /home/vpoint/testing.pl line 10, near "
+'/bin/bash' )
    "
Execution of /home/vpoint/testing.pl aborted due to compilation errors
+.
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I was trying to use the code exactly as you posted it. The only thing I removed was use warnings. The OS I am using is

 SunOS ferb 5.8 Generic_117350-21 sun4u sparc SUNW,Ultra-80

This is the perl version in case it helps.

 perl, version 5.005_03 built for sun4-solari

perl, version 5.005_03 built for sun4-solari

That explains it. Your ancient SunOS system is using an ancient Perl release. The code I posted requires Perl 5.8 or later, due to its use of the "3-argument" form of the open call, which wasn't available in perl 5.5 (which is what you have in this case). Sorry, I just assumed that no one would still be using such an old version of Perl.

To fix that, use the "2-argument" form for the open call -- like this:

#!/usr/bin/perl

use strict;
use warnings;

my @cmd_list = ( 'echo 1', 'echo 2', 'echo 3', 'echo 4' );

$|++;  # turn off buffering

my $shpid = open( my $sh, '|/bin/bash' )
    or die "Can't open a shell process: $!\n";

for my $cmd ( @cmd_list ) {
    print $sh "$cmd\n";
}
print $sh "exit\n";
close $sh;
waitpid( $shpid, 0 );

print "Shell's all done.  Moving right along...\n";
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That approach will also work with more recent versions of perl.