Here's a little subroutine I find quite handy when writing configuration scripts (or anything that needs to prompt for values from the shell). It lets you provide a prompt string and default arguments, and also lets you force the user to choose from a default list of args.

Example:

my @choices = ("yes", "no", "y", "n");

my $choice = query("Can you use an array for the choices?", "YES", @ch
+oices);

my $otherChoice = query("Can you use an invalid default to force them 
+to type in their choice?", "yes/no", "yes", "y");

my $finalChoice = query("Oh, just enter whatever you want.");

[download]

Hope you find this useful. ;)

Edit: Changed to a while(1) loop, and checked $_[0] on advice of q[uri] in efnet #perl
Edit2: Ditched array and used named scalars instead for clarity, also took a couple clues from Jeffa++ (grep/chomp directly). Now you can supply a null default and it will work. ;) Unless you supply a list of choices of course.
# &query(Prompt String, optional default, optional list of restrictive
+ choices)
#  If the choices are provided at the end, only one of those can be ch
+osen.
#  This is currently case insensitive.
#
# Example: my $val = query("Do you like config scripts?", "yes", "yes"
+, "no", "y", "n");
# Will print: Do you like config scripts? [yes]:
# The user can either press enter for yes, or enter one of the other a
+rguments.

sub query
{
    my $prompt = (defined $_[0]) ? $_[0] : "";
    my $default = (defined $_[1]) ? $_[1] : "";
    my $answer;
    
    while(1)
    {
        print "$prompt [$default]: ";
        chomp($answer = <STDIN>);
        
        $answer = $default if ($answer eq "");
        
        last unless $#_ > 1;
        last if grep $answer =~ /^\Q$_\E$/i, @_[2 .. $#_];        
    }
    
    return $answer;
}

[download]

In reply to Prompting via shell with default arguments by Azhrarn

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