Hi burszuras,

You may also be interested in the -t file test (on line 23): 

    -t  Filehandle is opened to a tty.

[download]
which is a nice way to discover whether you're at the tail end of a pipe or not.

For example: 

#!/usr/bin/perl

use strict;
use warnings;
use feature qw( say );
use File::Basename;

my $iam = basename($0);

if (-t *STDIN) {
    my $nargs = @ARGV;
    say "Script '$iam' called from a terminal with $nargs arg(s):";
    for (my $idx = 0; $idx < $nargs; $idx++) {
        printf "  %2d.  %s\n", $idx+1, $ARGV[$idx];
    }
} else {
    say "Script '$iam' is receiving input from a pipe";
}

[download]
Call the above script like this: ./script arg1 arg2 arg3 and you get: 
Script 'script' called from a terminal with 3 arg(s):
   1.  arg1
   2.  arg2
   3.  arg3

[download]
If you call it like this, instead: echo Pipe to script | ./script then you'll get this: 
Script 'script' is receiving input from a pipe

[download]
In the latter case, you could then do: 
    while (<STDIN>) {
        say "Got input:  $_";
    }

[download]
or similar, to handle the piped data as you desire.
say  substr+lc crypt(qw $i3 SI$),4,5

In reply to Re: Arguments from CLI or <STDIN> by golux
in thread Arguments from CLI or <STDIN> by burszuras

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