Path: utzoo!attcan!uunet!mcsun!cernvax!chx400!lengge
From: lengge@chx400.switch.ch (Thomas Lenggenhager)
Newsgroups: comp.lang.perl
Subject: Recursive Subroutines - Help sought
Message-ID: <1990Oct29.140931.5498@chx400.switch.ch>
Date: 29 Oct 90 14:09:31 GMT
Organization: SWITCH
Lines: 64

I am just a beginner with perl. I use it on a SUN 4/490, the version is
	$Header: perly.c,v 3.0.1.8 90/10/16 10:14:20 lwall Locked $
	Patch level: 36

This is my first perl program which should list all file entries of a
directory recursively. However what it does is listing the files of the
directory I give as input and the files of the first subdirectory but
then the program stops!
  It seems to me, that some variables are not recovered correctly on returning
from the subroutine, even by declaring them as local.

I know that I could have that much more easily, but the main intent was to
do some processing on each file of a sub-tree.

Who can find the bug in my program, or who suggests a better solution to my
problem.

Many thanks for your help in advance,
Thomas Lenggenhager
SWITCH

===============================================================================
     Thomas Lenggenhager, SWITCH, ETH-Zentrum, CH-8092 Zurich, Switzerland
          INET: lenggenhager@verw.switch.ch  | Tel: +41-1-261'8178
          UUCP: ..!mcsun!chx400!lenggenhager | Fax: +41-1-261'8133
         X.400: S=lenggenhager;OU=verw;O=switch;P=switch;A=arcom;C=ch

Here follows my perl program:
===============================================================================
#
# Ask for directory name and list fileentries recursively
#
print "Directory: ";
$dirname = <STDIN>;
chop($dirname);
do read_dir($dirname);
exit;

sub read_dir {
#
# Print all full filenames recursively to STDOUT
#
	local($dirname) = @_;
	local($file, $filename);
	open($file, "/bin/ls -AF $dirname|") || return ;
	while (<$file>) {
		$filename = $_;
		chop($filename);
		if ($filename =~ s|/$||) {
			$dirname = $dirname . "/" . $filename;
			print $dirname, "/\n";
			do read_dir($dirname);
		}
		else {
			print $dirname . "/" . $filename, "\n";
		}
	}
	close($file);
}
-- 
===============================================================================
     Thomas Lenggenhager, SWITCH, ETH-Zentrum, CH-8092 Zurich, Switzerland
          INET: lenggenhager@verw.switch.ch  | Tel: +41-1-261'8178
          UUCP: ..!mcsun!chx400!lenggenhager | Fax: +41-1-261'8133