Re: Read from multiple files change the data with a script and the write the respective output files with a different extension

I have tried a few methods unsuccessfully

You should have shown us those attempts, so we could help you understand why they failed, and how to improve them.

Anyway, a rather simple and straightforward solution to your problem, is to turn your code into a function:

sub process_file
{
  my ($original, $final) = @_;

  open( my $original_fh, "<", $original ) or die $!;
  open( my $final_fh,    ">", $final )    or die $!;

  my $first = <$original_fh>;
  print $final_fh $first;
  my @replace = $first =~ /"([^"]*)"/g;

  while (my $line = <$original_fh>) {
    print "Enter the desired number of columns: ";
          my $nr = <STDIN>;
          chomp($nr);
    $line =~ s/((\w\w\t){$nr})/$1\n/g;
    $line =~ s/\t/,/g;
    $line =~ s/(\d{2})/$replace[$1]/g;
    print $final_fh $line;
  }

  close $original_fh;
  close $final_fh;
}
[download]

And call that function on all your files (process_file("A.txt", "B.csv");).

You can get the list of files using glob ; this will return the list of files that match a given pattern: my @files = glob 'path/*.txt'; If you don't provide a path, glob will look into the current directory, which you can change with chdir.

And to change the extension, you can just use a substitution: my $new_file = $name =~ s/txt$/csv/r;

Edit: changed the last sentence, Akatsuki obviously already knows about substitutions.

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Re^2: Read from multiple files change the data with a script and the write the respective output files with a different extension by Akatsuki (Novice) on Oct 13, 2016 at 11:27 UTC
Thank you very much for your help, but after I turn my code into a function, I still can't figure out how to read all the files and replace the extension...I wrote something like this: #!/usr/bin/perl use warnings; use strict; sub process_file { my ($original, $final) = @_; open( my $original_fh, "<", $original ) or die $!; open( my $final_fh, ">", $final ) or die $!; my $first = <$original_fh>; print $final_fh $first; my @replace = $first =~ /"([^"])"/g; while (my $line = <$original_fh>) { print "Enter the desired number of columns: "; my $nr = <STDIN>; chomp($nr); $line =~ s/((\w\w\t){$nr})/$1\n/g; $line =~ s/\t/,/g; $line =~ s/(\d{2})/$replace[$1]/g; print $final_fh $line; } close $original_fh; close $final_fh; } my @files = glob '.txt'; my $new_file = $name =~ s/txt$/csv/r; process_file($files, $new_file); [download] but I know it can't run...I didn't quite understand how can I use the substitution that you wrote because I know that $name is not declared. I appreciate any advice you can give me!	[reply] [d/l]
Re^3: Read from multiple files change the data with a script and the write the respective output files with a different extension by hippo (Archbishop) on Oct 13, 2016 at 11:35 UTC
You have many files and want to process one at a time, so use a loop: `my @files = glob '*.txt'; for my $name (@files) { my $new_file = $name =~ s/txt$/csv/r; process_file($name, $new_file); }` [download]	[reply] [d/l]
Re^4: Read from multiple files change the data with a script and the write the respective output files with a different extension by Akatsuki (Novice) on Oct 13, 2016 at 13:54 UTC
If you could help me with another problem I encountered in this program I would be very grateful. I want to enter the number of columns, only once for all the files, not for every file. My original code is: `while (my $line = <$original_fh>) { print "Enter the desired number of columns: "; my $nr = <STDIN>; chomp($nr); $line =~ s/((\w\w\t){$nr})/$1\n/g; $line =~ s/\t/,/g; $line =~ s/(\d{2})/$replace[$1]/g; print $final_fh $line; }` [download] and I tried something like this unsuccessfully `while (my $line = <$original_fh>) { for my $file (@files) { print "Enter the desired number of columns: "; my $nr = <STDIN>; chomp($nr); $line =~ s/((\w\w\t){$nr})/$1\n/g; } $line =~ s/\t/,/g; $line =~ s/(\d{2})/$replace[$1]/g; print $final_fh $line; }` [download]	[reply] [d/l] [select]
Re^5: Read from multiple files change the data with a script and the write the respective output files with a different extension by hippo (Archbishop) on Oct 13, 2016 at 14:04 UTC
Re^6: Read from multiple files change the data with a script and the write the respective output files with a different extension by Akatsuki (Novice) on Oct 14, 2016 at 06:21 UTC
Re^5: Read from multiple files change the data with a script and the write the respective output files with a different extension -- plain english by Discipulus (Canon) on Oct 13, 2016 at 19:10 UTC
Re^6: Read from multiple files change the data with a script and the write the respective output files with a different extension -- plain english by Akatsuki (Novice) on Oct 14, 2016 at 06:53 UTC
Re^4: Read from multiple files change the data with a script and the write the respective output files with a different extension by Akatsuki (Novice) on Oct 13, 2016 at 12:02 UTC
Thank you very much for your help. It's all clear now.	[reply]