arivu198314 has asked for the wisdom of the Perl Monks concerning the following question:

I have a file with 50,000 lines of find and replace string.

for example
/Test/Sample/
/A/X/
...

Now i want to process the file with input file.

I have tried with usual method, it takes more than 1 hour.

Please advice.

|Arivu|

Replies are listed 'Best First'.
Re: Large file processing
by GrandFather (Saint) on Oct 01, 2010 at 04:06 UTC

    Show us your code. For a standard sort of "read the file line by line, edit each line and write it out" I would expect a modest size file such as you imply to be processed in a matter of seconds.

    True laziness is hard work
[reply]
      Indeed, and even faster if the entire file is loaded into memory at once, processed, and dumped.
[reply]
        My code is here. 
        #Usage: <Support-File> <Input-File>

undef $/;
open(TEXT, $ARGV[0]) or die $!;
my $text = <TEXT>;
close TEXT;

open(XML, $ARGV[1]) or die $!;
my $xml = <XML>;
close XML;

while($text =~ m/\/(.+)\/([^\/]+)\/[^\/]+$/mgi)
{
    my $FindWord = $1;
    my $ReplaceWord = $2;
    $xml =~ s/(>[^>]*\b)\Q$FindWord\E(\b[^>]*<)/$1$ReplaceWord$2/gi;
}

open(OUTXML, ">$ARGV[1]") or die $!;
print OUTXML $xml;
close OUTXML;

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