use strict;
#
# This script takes two file names, and copies the first one to the second.
#
if($#ARGV != 1) {
print STDERR "You must specify exactly two arguments.\n";
exit 4;
}
# If the output exists, confirm. This uses two standard string functions,
# substring and lower-case.
if( -e $ARGV[1]) {
print "Do you really want to overwrite $ARGV[1]? ";
my $resp = <STDIN>;
chomp $resp;
if(lc(substr($resp, 0, 1)) ne 'y') { exit 0; }
}
# Open the files.
open(INFILE, $ARGV[0]) or die "Cannot open $ARGV[0]: $!.\n";
open(OUTFILE, ">$ARGV[1]") or die "Cannot write $ARGV[1]: $!.\n";
while(my $l = <INFILE>) {
print OUTFILE $l;
}
close INFILE;
close OUTFILE;