Hi Monks,

I have written the following script to read the second column of many tab delimited files (~200) and merge them side by side in an output file. The input files have three columns, tab delimited separated and 6.9 million lines each. It will take forever, if I want to read and write 6.9 million lines. Do you have any other better solution to do it quicker and more efficient. 

#!/usr/bin/perl -w
my(@handles);
unlink"Results.txt"; #would loop if already present

for(<*.TI>){
  open($handles[@handles],$_);
}
open(OUTFILE,">Results.txt");

my$atleastone=1;
while($atleastone){
  $atleastone=0;
  for my$op(@handles){
    if($_=readline($op)){
      my@col=split;
      $col[1]+=0;  #otherwise you print nothing but a \t if column 2 i
+s undef
      print OUTFILE"$col[1]\t";
      $atleastone=1;
    }else{
      print OUTFILE"0\t";
    }
  }
  print OUTFILE"\n";
}
undef@handles; #closes all files
close(OUTFILE);

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In reply to Merging Many Files Side by Side by sesemin

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