in reply to Comparing two files

Ofcourse you could use Algorithm::Diff... 
#!/usr/bin/perl

use Algorithm::Diff qw(diff LCS);
use strict;

my @seq1 = ("A".."N");
my @seq2 = ("F".."Z");
my @diff = ();
my @lcs = ();
if (@diff = diff( \@seq1, \@seq2 ))  { }
# Not equal
# Same for (@lcs = diff( \@seq1, \@seq2 ))

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Greetz
Beatnik
... Quidquid perl dictum sit, altum viditur.

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Re: Re: Comparing two files
by Anonymous Monk on May 26, 2001 at 01:09 UTC
    Thanks guys for pitching in.I tried using the Array::compare. Here's my test.I took 15 folders containing the same 285 files.I ran File::compare,diff and array::compare.It took me 14 secs for the first,10min 30 sec for the second and close to 8 min for the third. I need something that's as fast as file::compare but tone that can take care of the whitespace and case issues. Is there any c function or the likes that are available that can be called from my perl code? Ram
[reply]

      I suggest you check elsewhere in this very thread to see something that will likely be very fast while still being very easy to write. [ I've really grown to like sorting replies by reputation (see your User Settings) ]

      Update: Though, if you want to ignore blank lines, then that won't work. So here: 

      my( $lineA, $lineB );
while( 1 ) {
    $lineA= do { while(<FILE1>){ last if /\S/ }; $_ };
    $lineB= do { while(<FILE2>){ last if /\S/ }; $_ };
    last   if  ! defined $lineA  ||  ! defined $lineB;
    for( $lineA, $lineB ) {
        s/\s+/ /g;
        s/^ //;
        s/ $//;
        $_= lc $_;
    }
    last   if  $lineA ne $lineB;
}
if(  defined($lineA)  ||  defined($lineB)  ) {
   warn "The files are different!\n";
}

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              - tye (but my friends call me "Tye")
[reply]
[d/l]
      The reason why Algorithm::Diff is slow, is because is has a totally different purpose (but can be used to do what you need). Algorithm::Diff is an implementation of UNIX's diff, which basically shows you the difference between files. Diff is used with patch when bugs are found/fixed.

      Anyway, more information is available on the Algorithm::Diff POD, Dominus has a page on it, and ofcourse, you can check the diff manpages

      Greetz
      Beatnik
      ... Quidquid perl dictum sit, altum viditur.
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