#! /usr/bin/perl -w
# scr07B.pl
# How to write an external file automatically?
# Please use open (OUT, ">filename.txt") with the mark of redirection ">".
open (IN, "Infile.txt"); ### FileHandle IN opens "Infile.txt" for reading.
open (OUT, ">Outfile.txt"); ### FileHandle OUT opens "Outfile.txt" for writing.
while(<IN>){
print $_; ## For screen (terminal) monitor
print OUT $_; ## Writing all of incoming each line into "Outfile.txt" by FileHandle OUT.
}
close (IN); ### Close FileHandles IN and OUT.
close (OUT);