Directory available?

kingjamesid has asked for the wisdom of the Perl Monks concerning the following question:

I have a dir and sub-dirs underneath it.Inside subdirs, i have files with extension *.mat( and may be some other dirs).

I am performing a recursive fn.

sub readFiles {
    my $ipath = $_[0];
    my $afile;
    opendir(sDir, $ipath) || die "unable to open sDir: $!";
    my @files = grep { /\.mat$/ } readdir(sDir);

    foreach (@files){
        print FILE "$ipath\\$_"."\n";
    }
    closedir(sDir);
}
[download]

But I need to say, based on a dir (argument to readFiles), check if there is any other dir, if so readFiles again. My question is, what is the command in perl that "checks if there is a directory in a given path). Thanks.

Comment on Directory available? Download Code

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Re: Directory available? by Corion (Patriarch) on Oct 19, 2009 at 16:57 UTC
Not only does Perl have an operator that tells you whether a directory entry is a directory, it also has File::Find, the standard module used for recursively descending through a directory tree. There are other contenders, like File::Find::Rule, File::Finder and others, all in the File::Find namespace.	[reply]
Re: Directory available? by ph0enix (Friar) on Oct 20, 2009 at 07:53 UTC
You can try following code (untested) `my $separator = ($^O eq 'MSWin') ? '\' : '/'; sub readFiles { my $ipath = shift; my @files; opendir(sDir, $ipath) \|\| die "Unable to open directory '$ipath': $!"; for (readdir(sDir)) { if (!/^\.{1,2}$/ && -d $iPath . $separator . $_) { # recursive call for directory readFiles($iPath . $separator . $_); } else { # collect matching files push @files, $_ if /\.mat$/; } } closedir(sDir); for (@files){ print FILE $ipath, $separator, $_, "\n"; } }` [download]	[reply] [d/l]
Re^2: Directory available? by kingjamesid (Acolyte) on Oct 24, 2009 at 23:56 UTC
Thanks	[reply]
Re^2: Directory available? by afoken (Chancellor) on Oct 25, 2009 at 08:52 UTC
Notes and Problems: Windows (and DOS and OS/2) accepts a forward slash as path separator, there is no need for `$separator`. If you want true multi-platform code, use File::Spec, which also handles classic MacOS and more exotic platforms. `$^O` is never `MSWin`. It may be `MSWin32` or perhaps `MSWin64`. `readFiles()` is a bad name, as this function does not read files. It reads directories and print file names found there matching a hardcoded regular expression. The function should really `return` a list of file names instead of `print`ing them. Recursion is not needed here, you could use a simple worklist (array) instead, containing directories to be processed. Because you use a global directory handle (`sDir`) instead of a local handle (`my $dir`) or at least a localized handle (`local *sDir`), every recursion will automatically close and re-open the handle. Your code only works by accident, because you used `for (readdir(sDir))` instead of `while (defined($_=readdir(sDir)))`, reading the entire directory list into memory before iterating over it. Still, each and every call to `closedir` except for the first one will fail with "Bad file descriptor". There is no need to reinvent directory tree walkers, there are several on CPAN that do not pollute namespaces, that properly check for errors, that work cross-platform, and that do not slurp everything into memory. And, of course, they have parameters allowing to customize the search. Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply] [d/l] [select]