How to open files found via File::Find

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

Dear Monks,

I'm trying trying to process all .dat files in a nested directory tree. I've used the File::Find module but it's not working how I expected it to work. I can't even concatenate the directory and the filename to open the files. I always get the error message "readline() on closed filehandle"

Any help would be deeply appreciated!

Here is the code:

use strict;
use warnings;
use Cwd;

my $startdirectory = cwd;
print "Starting directory:  $startdirectory\n";
use File::Find;
  find ( \&inFiles, ('.') );
exit;

sub inFiles {
chomp;
my $name = $_;

my $directory = cwd;


if( $name =~ /.dat/) {
  print "dir = $directory\tname = $name\n";

  
  open INFILE,'<$name'  || warn ("Cannot open input file $name\n");
  my @infilecontent = <INFILE>;
  print @infilecontent;

  my $localfile = "$directory\$name";  #win32 
  open INFILE2,'<$localfile'  || warn ("Cannot open input file $localf
+ile\n");
  @infilecontent = <INFILE2>;
  print @infilecontent;
 } 

 } #inFiles
[download]

Comment on How to open files found via File::Find Download Code

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Re: How to open files found via File::Find by ikegami (Patriarch) on Jan 08, 2010 at 00:30 UTC
You're not getting the errors you should because `open INFILE,'<$name' \|\| warn ("Cannot open input file $name\n");` [download] means `open INFILE, ( '<$name' \|\| warn ("Cannot open input file $name\n") );` [download] which is the same as the following (since `'<$name'` is always true): `open INFILE, '<$name'` [download] You want to use parens or lower-precedence "or": `open(INFILE, '<$name') \|\| warn ("Cannot open input file $name\n");` [download] or `open INFILE, '<$name' or warn ("Cannot open input file $name\n");` [download] Then there's the problem that `'<$name'` produces the five character `< $ n a m e`. You need to use double-quote to interpolate. `open(INFILE, "<$name") or warn ("Cannot open input file $name\n");` [download] Or better yet, use the safer, more reliable 3-arg open: `open(INFILE, '<', $name) or warn("Cannot open input file $name: $!\n");` [download] Finally, `$_` only contains the name of the file, not the path to the file. You need to use `$File::Find::name`. `open(INFILE, '<', $File::Find::name) or warn("Cannot open input file $File::Find::name: $!\n");` [download] There's also a problem with `"$directory\$name"` [download] The backslash before the `$` tells Perl to treat the `$` as a non-special character. You want `"$directory\\$name"` [download] The following would also be fine: `"$directory/$name"` [download] Yes, even on Windows. Windows accepts both slashes.	[reply] [d/l] [select]
Re^2: How to open files found via File::Find by jwkrahn (Abbot) on Jan 08, 2010 at 07:28 UTC
Finally, `$_` only contains the name of the file, not the path to the file. You need to use `$File::Find::name`. Actually, `File::File::find()` changes directories while tranversing the file system so `$_` doesn't need the path because `$_` is in the CWD (which is in `$File::Find::dir`).	[reply] [d/l] [select]
Re: How to open files found via File::Find by gam3 (Curate) on Jan 08, 2010 at 00:33 UTC
You are using single quotes in you open statements. try `open INFILE2,'<', $localfile ...` [download] and you should have better luck. You also need 2 backslashes in a double quoted string. Or use `$directory . '\' . $name`. use strict; use warnings; use Cwd; my $startdirectory = cwd; print "Starting directory: $startdirectory\n"; use File::Find; find ( \&inFiles, ('.') ); exit; sub inFiles { chomp; my $name = $_; my $directory = cwd; if ( $name =~ /.dat/) { print "dir = $directory\tname = $name\n"; open INFILE,'<', "$directory/$name" \|\| warn ("Cannot open input fil +e $name\n"); my @infilecontent = <INFILE>; print length @infilecontent; my $localfile = "$directory\\$name"; #win32 open INFILE2,'<', $localfile \|\| warn ("Cannot open input file $loca +lfile\n"); @infilecontent = <INFILE2>; print @infilecontent; } } #inFiles [download] -- gam3 A picture is worth a thousand words, but takes 200K.	[reply] [d/l] [select]
Re^2: How to open files found via File::Find by roboticus (Chancellor) on Jan 08, 2010 at 14:07 UTC
For better portability, I'd suggest using "/" rather than "\\" as a directory separator. ...roboticus	[reply]
Re^3: How to open files found via File::Find by gam3 (Curate) on Jan 08, 2010 at 19:15 UTC
Or even better use `File::Spec->catfile`. -- gam3 A picture is worth a thousand words, but takes 200K.	[reply]