[SOLVED] perl simple recursive sub

sharky · 02-16-2011, 03:20 PM

This is my sub;

Code:

sub projName
{
    print "Enter project name: " ;
    $PROJ = <STDIN>;
    print "";
    if (-d "${PROJ}") 
    {
        print "Good project\n";
    }
    else
    {
        print "Not a valid project name. Try again\n" ;
        projName;
    }
}

I can call this routine and it works fine when I enter a valid name for $PROJ. If I enter an invalid name it goes to the else block and prints the statement. However, it does not call itself. Instead the script just exits.

I've googled 'perl recursive subroutines' and the example don't appear to be doing anything different.

Any ideas what I'm doing wrong?

Tinkster · 02-16-2011, 03:41 PM

Not sure what your problem is ...

Code:

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

sub projName;

projName;

sub projName
{
  my $PROJ;
  print "Enter project name: " ;
  $PROJ = <STDIN>;
  chomp $PROJ;
  print "";
  if (-d "${PROJ}")
  {
    print "Good project\n";
  }
  else
  {
    print "Not a valid project name. Try again\n" ;
    projName;
  }
}

Code:

$ perl sub.pl
Enter project name: blah
Not a valid project name. Try again
Enter project name: yadda
Not a valid project name. Try again
Enter project name: mangle    
Good project

works as designed.

Cheers,
Tink

P.S.: I'm moving this over to programming where it's better suited.

sharky · 02-16-2011, 04:16 PM

Quote:

Originally Posted by Tinkster

Not sure what your problem is ...

Code:

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

sub projName;

projName;

sub projName
{
  my $PROJ;
  print "Enter project name: " ;
  $PROJ = <STDIN>;
  chomp $PROJ;
  print "";
  if (-d "${PROJ}")
  {
    print "Good project\n";
  }
  else
  {
    print "Not a valid project name. Try again\n" ;
    projName;
  }
}

Code:

$ perl sub.pl
Enter project name: blah
Not a valid project name. Try again
Enter project name: yadda
Not a valid project name. Try again
Enter project name: mangle    
Good project

works as designed.

Cheers,
Tink

P.S.: I'm moving this over to programming where it's better suited.

Hi Tinkster, I may have had several problems. I did not have a line "sub projName" in my script before the subroutine is written, I did not 'use strict', I did not declare 'my $PROJ' and I called projName after the subroutine in my script. Not sure which specifically made it work.

Thanks to you it's working now.

Regards,

sharky · 02-16-2011, 04:19 PM

I also didn't 'chomp $PROJ'. Without that it is never a valid name.

Tinkster · 02-16-2011, 04:28 PM

Quote:

Originally Posted by sharky

I also didn't 'chomp $PROJ'. Without that it is never a valid name.

Heh. Glad it's settled; just for future reference:
it's ALWAYS adivsable to do both the "-w" and "use strict;".

Helps avoiding head-aches in the long run.

Cheers,
Tink