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

Hi
I am trying to write an interactive perl script which will check the commandl line for a message and if the check is successful it will assign 'yes' otherwise will take it from the <STDIN>. Based on the answer, if it is 'yes' the script should continue else it would take the necessary action.
Please refer to the code below which I am trying 

use Term::ReadLine;


# Initialize the term variable for the keyborad input
my $TERM = new Term::ReadLine 'Installer';
my $OUT = $TERM->OUT || \*STDOUT; 

my $prompt  = "Would you like to continue\n";
my $ans;
$ans = ($TERM->readline($prompt)) ? : 'yes' :<STDIN> ;


chomp($ans);
print "ans is $ans \n";

if($ans =~ /yes/)
{
   print "yes and continue\n";
}
else 
{
   print "no and take action\n";
}

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Re: how to take user input from command line and continue
by mtmcc (Hermit) on Apr 10, 2014 at 10:42 UTC
    It isn't fully clear what you'd like to do from your question. Presuming you have a good reason for wanting to use Term::Readline (which you don't need to process command line variables) then something like this might be what you're looking for: 

    #!/usr/bin/perl
use strict;
use warnings;
use Term::ReadLine;

# Initialize the term variable for the keyborad input
my $commandLineMessage = $ARGV[0];
my $TERM = new Term::ReadLine 'Installer';
my $OUT = $TERM->OUT || \*STDOUT; 
my $prompt  = "Would you like to continue?\n";

my $ans = 'yes' if $commandLineMessage eq 'yes';
$ans = $TERM->readline($prompt) if $commandLineMessage ne 'yes';

chomp($ans);
print "ans is $ans \n";

if($ans =~ /yes/)
    {
       print "yes and continue\n";
    }
else 
    {
       print "no and take action\n";
    }

    [download]

    If you had used strict and warnings, you would have found the main syntactical error in this line:

    $ans = ($TERM->readline($prompt)) ? : 'yes' :<STDIN> ;

    [download]

    which means "if a response is given, then $ans is yes, if no response is given, get a line from standard input". Which in turn means that $ans will always be set to yes if the user gives any input at all.

    I hope that helps

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Re: how to take user input from command line and continue
by Bloodnok (Vicar) on Apr 10, 2014 at 10:26 UTC
    ...and your problem is what exactly?? Your problem statement and code are quite clear, but you completely fail to mention which aspect is causing you problems &/or exactly the wisdom that you seek.

    A user level that continues to overstate my experience :-))
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