Question

How to check if file exists case insensitive

Asked by: yuk99

Hello,
I usually check if file exist with
(-e $filename) or die "$filename does not exist\n";
Windows and Mac OS X have case-insensitive file system, but this check is case sensitive. So if $filename='test.TXT', my code return false even if test.txt file exists.
I would like not to use any packages, only standard Perl to be sure it will run on any computer without installing additional packages.
What I can do? There should be an easy solution, but I could not find a good one.
I saw some recommended to do it with ls and grep, but it looks wierd. I cannot believe Perl does not deal with this issue.
Any ideas?
Thanks

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Asked On
2009-04-16 at 08:13:13ID24328305
Tags

perl

,

file

,

exist

,

case insensitive

Topic

Perl Programming Language

Participating Experts
3
Points
500
Comments
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Answers

 

by: Adam314Posted on 2009-04-16 at 08:15:09ID: 24158671

(grep /$filename/i <*>) or die "$filename does not exist\n";

 

by: yuk99Posted on 2009-04-16 at 08:56:21ID: 24159226

Adam314, thanks.
What <*> actually means for grep?
I got an error on both Windows and Mac:
Not enough arguments for grep at test.pl line 7, near "*>)  "

On Win Perl 5.10.0, on Mac - 5.8.6

 

by: ghostdog74Posted on 2009-04-16 at 09:17:09ID: 24159441

just change $filename to lowercase  and do the test

-f lc($filename) && print "file exists";

                                              
1:

Select allOpen in new window

 

by: yuk99Posted on 2009-04-16 at 09:30:30ID: 24159571

OK, I found my mistake and it was stupid. I didn't specify the whole path in $filename.
So my original code works under Mac and Windows.

But the problem is still exists now on Unix with case-sensitive file system. I want to eliminate the possibility that case has been changed.

ghostdog74
Your code does not work. It changes the variable name to lower case, but the file can be in upper or mixed case.

 

by: yuk99Posted on 2009-04-16 at 10:35:31ID: 24160228

Finally I've go it working. The code is below.

(grep {/$file/i} <$dir/*>) or die "$file not exist in $dir\n";

                                              
1:

Select allOpen in new window

 

by: yuk99Posted on 2009-04-16 at 10:37:16ID: 31571024

Adam314,
Thanks a lot for the hint!

 

by: ozoPosted on 2009-04-16 at 12:20:40ID: 24161483

grep /^\Q$filename\E$/i ,<*> or die "$filename does not exist\n";

 

by: ozoPosted on 2009-04-16 at 12:23:40ID: 24161505

otherwise
 $filename='test.TXT'
may match on
dir/__test_TXT__
and
$filename='test)TXT'
would cause an error

 

by: ghostdog74Posted on 2009-04-16 at 17:17:04ID: 24164024

>>Your code does not work. It changes the variable name to lower case, but the file can be in upper or mixed case.

i thought you wanted to check case-insensitive. ie Test.txt and test.txt both are allowed.

 

by: yuk99Posted on 2009-04-16 at 18:52:26ID: 24164401

ozo,
thanks for the comment. Although it's seems to be quite impossible situation in my case, little precaution won't harm.

ghostdog74,
You are right. Any case allowed - text.txt or Text.TXT should match. But converting just variable to lower case will not help.

Thanks again everybody. I've learned a lot.

20120131-EE-VQP-002

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