Dear Perl Monks,

perl-5.16.3-286.el7.x86_64

I seek the following wisdom. I am trying to create a sample .pl script to demonstrate how to:

1) read a pipe and read parameters at the same time, and

2) not hang if the pipe is empty

This is basically the thing I am trying to demonstrate:
ls -al | grep -i xxx
where the grep both reads parameters and the pipe.

This is what I have so far and the resulting errors (I still hang on an empty pipe)

#!/usr/bin/perl

use strict;
use warnings;

my $Pipe= "";

while (<>){   # replaced in Perl 5.22 with "for ( @ARGV )"
# Reference: http://www.perlmonks.org/?node_id=1175906
# for ( @ARGV ) {
   $Pipe .= $_;
}

print "This was read from the pipe:\n";
print "<$Pipe>\n\n";

print "This was the read from the parameters:\n";
print "<@{ARGV}>\n";
__END__

[download]

$ ( echo Hi; sleep 3; echo Bye ) | ./ReadAPipe.pl 1 2 3 4
Can't open 1: No such file or directory at ./ReadAPipe.pl line 9.
Can't open 2: No such file or directory at ./ReadAPipe.pl line 9.
Can't open 3: No such file or directory at ./ReadAPipe.pl line 9.
Can't open 4: No such file or directory at ./ReadAPipe.pl line 9.
This was read from the pipe:
<>

This was the read from the parameters:
<>


Many thanks,
-T

In reply to Need pipe and parameter help by Todd Chester

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