he204035 has asked for the wisdom of the Perl Monks concerning the following question:

I have some code to open a text file, and based on what is found in the text I am analyzing, place the line of text in a different file.

I am opening the receiving files as "append", but the files keep getting written over, not appended:

 
foreach $subdir(@subdirs) {
     chdir($subdir);
     @files=();
     @files = glob "*.txt";
     foreach $file(@files) {
         open(MYFILE, "<", $file);
         open($ohfivei, '>>905i.txt');
         open($ohthreei, '>>903i.txt');
         open($teni, '>>910i.txt');
         open($ohfiveo, '>>905o.txt');
         open($ohthreeo, '>>903o.txt');
         open($teno, '>>910o.txt');
         while ($line=<MYFILE>) {
          #print "$_\n";
          if($line=~(/$subdir/)) {
              ($undef, $mon, $day, $yr, $hr, $undef, $undef, $pr, $dir
+, $cc, $undef, $undef, $pegs, $undef) = split /,/, $line;
              $dt = ("$mon-$day-$yr $hr:00");
              if ($pr=="905") {
                 if($dir=="1") {
                     print $ohfivei "$dt,$cc,$pegs\n";
                 } elsif($dir=="2") {
                     print $ohfiveo "$dt,$cc,$pegs\n";
                 }
               } elsif ($pr=="903") {
                 if($dir=="1") {
                     print $ohthreei "$dt,$cc,$pegs\n";
                 } elsif($dir=="2") {
                     print $ohthreeo "$dt,$cc,$pegs\n";
                 }
               } elsif ($pr=="910") {
                     if($dir=="1") {
                     print $teni "$dt,$cc,$pegs\n";
                 } elsif($dir=="2") {
                     print $teno "$dt,$cc,$pegs\n";
                 }
               }
          }
         }
          close MYFILE;
          close $ohfivei;
          close $ohthreei;
          close $teni;
          close $ohfiveo;
          close $ohthreeo;
          close $teno;
          unlink "$file";

[download]

I have tried using an ALLCAPS filehandle instead of "$fh" format, but I get the same thing. I have also tried double-quoting the ">>", with the same results.

.

I think I may be to the point of "can't see the forest through the trees", so I thought I would ask for help.

Replies are listed 'Best First'.
Re: File APPEND/OVERWRITE
by runrig (Abbot) on Feb 08, 2012 at 22:37 UTC
    If you are not using autodie, then you should be checking the status of each of your open statements, e.g.:
    open(my $fh, ">>", $myfile) or die "Failed to open $myfile: $!";

    [download]
    Similarly, you should also check the status of chdir
[reply]
[d/l]

      I tried the "or die" and the files all seem to be opening fine...(no death notices.. :-)

      I am wondering about something...earlier in my code, I have a line of code to do a "mkdir", which I assumed would act the same as if I was doing it by hand...i.e. if a mkdir is entered on a subdirectory that already exists, it will just go in with life...:

      foreach (@text) {
   $first = substr($_,0,11);
   mkdir "$first";
   print "Copying $_ to $first.\n";
   copy($_,"$first/$_");
   unlink $_;
     }

      [download]

      I am wondering if that "mkdir" is actually re-creating the sub-directories, which if so I guess would wipe out anything that was in there previously?

[reply]
[d/l]
        I am wondering if that "mkdir" is actually re-creating the sub-directories
        Not really. Try it: 
        mkdir 'XXX';
open my $FH, '>', 'XXX/1';
close $FH; 
mkdir "XXX" or warn $!;
open my $FH, '<', 'XXX/1' or die $!;
close $FH;

        [download]
[reply]
[d/l]
Re: File APPEND/OVERWRITE
by kielstirling (Scribe) on Feb 09, 2012 at 07:00 UTC

    You may want to look at opening the output files outside the main foreach loop. I suspect this is your problem. You are opening the same file each time you loop over @files. So the amount of entrees in the list will determine the amount of open file handles. If you must do it that way at least call close within the @files loop Also you should always check for any errors when opening a file.

    i.e 
    open FH, "<file>" or die $!;

    [download]

    This simple check can give you back hours of your life ;)

[reply]
[d/l]
Re: File APPEND/OVERWRITE
by Anonymous Monk on Feb 08, 2012 at 22:36 UTC

    I am opening the receiving files as "append", but the files keep getting written over, not appended:

    Impossible :) Actually, what kind of operating system/file system are you using?

    It might be a good idea to use autodie; since you're currently not doing any error checking

[reply]

Back to Seekers of Perl Wisdom