Bad file descriptor

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

My PERL development was revolving up to now around web and database connectivity. Now, I'm trying to use it in my day-to-day sysadmin task on our UNIX boxes. Here is a very simple script which gives my some trouble for one reason or another:

open(DIR, ".") or die "Can't open the current directory: $!\n";

my @names = readdir(DIR) or die "Unable to read current dir: $!\n";
closedir(DIR);

foreach my $name (@names) {
    next if ($name eq ".");
    next if ($name eq "..");
    
    if (-d $name) {
        print "found a directory: $name\n";
        next;
    }
    
    if ($name eq 'core') {
        print "found 'core' file!\n";
    }
}
[download]

The script dies at my @names = readdir(DIR) or die "Unable to read current dir: $!\n"; closedir(DIR); with a "Bad file descriptor" error message.

What does that mean?

Thanks.

Comment on Bad file descriptor Download Code

Replies are listed 'Best First'.
Re (tilly) 1: Bad file descriptor by tilly (Archbishop) on Jan 28, 2001 at 06:16 UTC
You used open rather than opendir.	[reply]
Re: Re (tilly) 1: Bad file descriptor by bman (Sexton) on Jan 28, 2001 at 06:30 UTC
Oops. That's why I like coming here! I was staring at my code not seeing the obivious. Thanks for pointing this out! :-)	[reply]
Re: Bad file descriptor by moen (Hermit) on Jan 28, 2001 at 06:17 UTC
That should be: `opendir(DIR, ".") or die "Can't open the current directory: $!\n";` [download] instead of just open()	[reply] [d/l]
Re: Bad file descriptor by Beatnik (Parson) on Jan 28, 2001 at 06:23 UTC
It means a filehandles != a dirhandle. Use `opendir()` to open a dir for `readdir()`. Greetz Beatnik ... Quidquid perl dictum sit, altum viditur.	[reply] [d/l] [select]
Re: Bad file descriptor by quidity (Pilgrim) on Jan 28, 2001 at 06:18 UTC
You'll not be wanting `open` rather `opendir`: opendir DIRHANDLE,EXPR Opens a directory named EXPR for processing by readdir, telldir, seekdir, rewinddir, and closedir. Returns true if successful. DIRHANDLEs have their own namespace separate from FILEHANDLEs.	[reply] [d/l] [select]