I re-encountered this the other day The following code pukes why?:

01: #!/usr/local/bin/perl -wT

03: open(FH,'data.txt')
04:    or die "couldn't open file $!\n";

06: my $data_dir=<FH>;
07: chomp($data_dir);
08: close(FH)
09:    or die "couldn't close file $!";

10: opendir(DH,$data_dir)
11:    or die "couldn't open #$data_dir# $!\n";

12: my @files=readdir(DH)
13:    or die "couldn't read dir\n";

14: print join("\n",@files);
[download]

HINT (contents of data.txt)

The data.txt contained a single line: ../ [download]

HINT (exact error message)

# No such file or directory

HINT (How the code was created)

All files were created in win2K notepad and ftp'd up to a LINUX box with DreamWeaver's check-in mechanism.

HINT (error message after removing a line)

After removing line 07 the error message became: couldn't open #../ # No such file or directory [download]

HINT (How the problem will be avoided in the future)

The following line was inserted between lines 07 and 08 $data_dir=~s/\r//g; [download]

EXPLAINATION

Microsoft ends lines with a \r\n a carrage return and newline or \r\n. UNIX ends them with a \n When I read a line of text from my file, I accedently included a carrage return which became part of the directory name I was trying to open. ../\r is not a directory that exists on my LINUX system.