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From: tshiono@cv.sony.co.jp (Toru SHIONO)
Newsgroups: comp.lang.perl
Subject: Re: Tree traversal - call for algorithms
Message-ID: <TSHIONO.93Nov06081827@aquarius.cv.sony.co.jp>
Date: 6 Nov 93 08:18:27 GMT
References: <14510@lhdsy1.lahabra.chevron.com> <1993Nov5.004308.4678@btree.uucp> <Nov.2.18.56.51.1993.27804@pilot.njin.net> <14510@lhdsy1.lahabra.chevron.com> <3838@symbas.UUCP>
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In-reply-to: hans@symbas.lind.no's message of 4 Nov 93 14:37:55 GMT

In article <3838@symbas.UUCP> hans@symbas.lind.no writes:

: I have a 3 level directory tree with an arbitrary number of files
: in each leaf directory.
: My task is to traverse the tree and examine each file.
:
: I've struggled with readdir and a couple of "for each" loops
: inside each other, but have run into unforeseen trouble.
:
: I assume, however, that this classical task is more elegantly
: solvable by a recursive allgorithm or some perl primitive.
: 
: Any suggestions out there ??

There is a good example named `dodir' in the Camel, page 56.
Or here is a small script which might be easy to start with:

#!/usr/local/bin/perl

&traverse('.');

sub traverse {
    local($dir) = shift;
    local($path);
    unless (opendir(DIR, $dir)) {
	warn "Can't open $dir\n";
	closedir(DIR);
	return;
    }
    foreach (readdir(DIR)) {
	next if $_ eq '.' || $_ eq '..';
	$path = "$dir/$_";
	if (-d $path) {		# a directory
	    &traverse($path);
	} elsif (-f _) {	# a plain file
	    print "$path\n";
	    # or do something you want to
	}
    }
    closedir(DIR);
}
--
Toru "devil-may-care" Shiono          Sony Corporation, JAPAN