in reply to Trying to simulate a CLI using hashes...

Well, first off, why don't you just make you orignal hash something like this: 

    my %commands = (
        cmd1 => \&do_cmd1,
        cmd2 => \&do_cmd2,
        ....
    );

[download]

This buys you the flexibility of passing arguments to the subs, if you so wish to 

    ## untested, just something I thought up right now
    chomp( $input = <STDIN> );
    my( $cmd, @args ) = split( /\s+/, $input );

    if( defined( $commands{ $cmd } ) ) {
        $command{ $cmd }->( @args );
    }

[download]

Obviously you would need to do more error checking and what not, but you get the idea. Also, if you might want to try useing Term::ReadLine and its related modules for soemthing like this. It's quite handy

Replies are listed 'Best First'.
Re: (lestrrat) Re: Trying to simulate a CLI using hashes...
by thoth (Novice) on Jan 22, 2002 at 07:08 UTC
    Hmmm, when I try to create a hash similar to the one that you suggested, it just runs the routines...I am new to perl, so I'm not sure if I typed something in wrong or not. Program outputs Welcome Ending Program Died at..... I must have mis-understood what you were trying to explain with the hash. 
    use strict;
my $input;
my %commands;
my $cmd;

my %commands = (
        greeting =>  \&greeting(),
        quit  => \&end_program(),
    );


    chomp( $input = <STDIN> );
    my( $cmd, @args ) = split( /\s+/, $input );

    if( defined( $commands{ $cmd } ) ) {
        $commands{ $cmd }->( @args );
    }



sub greeting {
   print "Weclome\n";
}


sub end_program {
   print("Ending Program\n");
   die;
}

    [download]
[reply]
[d/l]

      No no, don't put them parathesis! That makes perl evaluate the subroutine, and put the ref to the result of the sub in the hash 

          my $rv = mysub();     ## sub is executed. normal
    my $rv = &mysyb();    ## same as above, but bad style, I think
    my $rv = \&mysub;     ## ref to the subroutine <- this is what we 
+want
    my $rv = \&mysub();   ## ref to the return value of the subroutine
    my $rv = \{ &mysub() }; ## same as above

      [download]

      UPDATE: wog corrected me: "\{ &mysub() } creates a reference to a refrence to a hash generated from mysub() returns in list context,". I apologize for the mistake :-(

[reply]
[d/l]

In Section Seekers of Perl Wisdom