Hellow fellow monks, I wrote a code to update names of variables in another code to follow a new naming rules. It does: 
read in a mapping table
read in an input file;
replace some variable names with new ones (regex);
write it to an input file;

[download]
The code looks like: 

open(MAP, "<$new_name_map_file");
while (<MAP>) {
     chomp;
     tr/A-Z/a-z/;
     @map_line = split (/\t/);
     $mapper{$map_line[0]} = $map_line[1];
}
close(MAP);
 
open(IN, "<input_file");
open(OUT, ">input_file.new");
while (<IN>) {
print "%";
     tr/A-Z/a-z/;
     foreach $key (sort keys %mapper) {
        s/\b$key\b/$mapper{$key}/g;
     }
     print OUT "$_";
}
close(IN);
clse(OUT);

[download]
I have ~15000 lines in the input file and ~8000 lines(entries) in the new naming mapping file. My script runs hours to finish it. Please let me know if you know better way to speed the code up. Please assume I can't buy any hardware:-( From a poor monk.

In reply to How to speed up multiple regex in a loop for a big data? by Anonymous Monk

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