Re: Multiple file input into a perl script

[Corion]

in reply to Multiple file input into a perl script

It depends. How do you find all those files? If you have them in a text file, read them from that text file:

use strict;
my $filename = 'my_textfile.txt';
open my $fh, $filename
    or die "Couldn't read '$filename': $!";

chomp @ARGV = <$fh>;

print "Processing $_"
    for @ARGV;

If they all are below a certain directory, use File::Find:

use strict;
use File::Find;

my $directory = '/home/kelder/files';

find(sub {
    push @ARGV, $File::Find::name;
}, $directory );

print "Processing $_"
    for @ARGV;

If you want to use a shell glob pattern, you can prevent the shell from expanding it and do the expansion in Perl:

use strict;
use File::DosGlob qw(bsd_glob); # to get sane whitespace semantics

my $pattern = '/home/kelder/files/*.txt';

@ARGV = glob $pattern;

print "Processing $_"
    for @ARGV;

If you have the list in some other fashion, you'll have to tell us, but the basic pattern remains.

[kelder]

I thought about using the glob function, since all of my files are in the same directory, but because I'm new to perl I might be misuing the format: My Code:

@files=<ABi1*>;
foreach $file (@files) {
    while(<>) {
          Do my function;
     }
    if (eof($file)) {
           Do my end of file cleanup
    }
}

Does the way I set this up work, or am I completely screwing up the way you are supposed to use this function?

[Corion]

The magic diamond-operator <> only works if you stuff the filenames into @ARGV. But you surely have tried that yourself and merely forgot to tell me that you found your code didn't work the way you wrote it.

I recommend you read up on open to learn how to open and read a single file and process that, and then proceed to do that in the loop:

use strict;
use File::DosGlob qw(bsd_glob);

my @files = glob 'ABi1*';
foreach my $file (@files) {
    open my $fh, '<', $file
        or die "Couldn't read '$file': $!";
    while (<$fh>) {
        ... do your function
    };
    # EOF, do end of file cleanup
};

[broomduster]

The magic diamond-operator <> only works if you stuff the filenames into @ARGV.

My reading of I/O Operators has me believing that using the diamond operator for globbing works as the OP seems to expect. Here's what I get with a simple test:

-> ls
file1.txt       file2.txt       file3.txt
-> perl -le '@files = <file*>; print @files;'
file1.txt file2.txt file3.txt

I may have missed something, but it looks to me that kelder's expectation of how globbing works with <> is right. Is there a platform difference to worry about? (OP is on a Mac, above test runs the same on a Mac and under NetBSD.)

[kelder]

This worked out great:

use File::DosGlob qw(bsd_glob); # to get sane whitespace semantics

my $pattern = '/home/kelder/files/*.txt';

@ARGV = glob $pattern;

Only there is a new problem; my output file list reads like this:

Ai0.txt
Ai1.txt
Ai2.txt
...
Ai10.txt
Ai11.txt

What ends up happening is that in my "results" file, where I print my counts, the order of the inputs is messed up.

Output:
File1
File10
File11
File2

How do I fix this ordering? Can I input the files in the order they are in the directory with another method? Thanks for all of the help so far!!

[Corion]

Maybe you want to sort your output? You don't tell us in what order you want it sorted, so I'm going to recommend tye's [ Natural Sort ]: Sorting a string with numbers.

[kelder]

Sorting would be very useful, only I want to be able to sort the input files before I use their input- can I use the sort function on  @ARGV=glob $mypattern?