Pre-evaluate string parameter

[shiftee]

Hi all,

I am trying to call a function using an interpolated string as the parameter.
Can it be done like this or do I need to stick an eval around it or something like that??

my $dirname = "/experiments/$experiment_name";

Fyp::Security::log( "Creating dir $dirname\n" );

I am using strict

Thanks,
Mark

[Eliya]

Sure, you can do it like this, no need for eval here.

What happened when you tried?

#!/usr/bin/perl -w
use strict;

package Fyp::Security;

sub log {
    my $arg = shift;
    print $arg;
};

package main;

my $experiment_name = 'foo';
my $dirname = "/experiments/$experiment_name";

Fyp::Security::log( "Creating dir $dirname\n" );

Interpolation - just like concatenation, i.e. "Creating dir " . $dirname . "\n" - happens at runtime, so you can arbitrarily "chain" interpolations  (if that's what your question is...)

[shiftee]

Oh, damn, I had defined the log function with empty parentheses like so:

sub log() {
...
}

Theres no helping a true idiot,
Thanks!!

[AnomalousMonk]

    (original post)
I am trying to call a function using an interpolated string as the parameter.
Can it be done like this ...?
I am using strict ...

    (subsequent post)
... I had defined the log function with empty parentheses ...

shiftee: If you had originally posted the error message reported by Perl (and the code around-about the indicated line number), the humble monks might have avoided a dead-end side-trip along the path to giving you a pertinent answer to your question.

>perl -wMstrict -le
"sub foo () { print 'hi, i am foo'; }
 ;;
 main::foo('this is an argument');
"
Too many arguments for main::foo at -e line 1, near "'this is an argum
+ent')"
Execution of -e aborted due to compilation errors.

[GrandFather]

Short version: Don't use prototypes.

Longer version: Prototypes don't do what you think they do so you shouldn't use them until you have read the perlsub documentation and really understand what's going on. Then you will know that most the time prototypes are not what you want.

[aartist]

You might just want to validate $dirname.