Re: edit / seek woes

On Aug 29, Brent Clark said:

Would someone be so kind as to please over look me code and if possible, point out where I am going wrong.

Would you be so kind as to explain what happens with it that you didn't expect to happen? (Or what doesn't happen that you'd expected to happen.)

open(HDATFILE, "+< $fileName.dat") or die "Cant open file $fileName.dat $!";
flock (HDATFILE, LOCK_EX) or die "Cant lock file $fileName.dat $!";


Make sure you're including the Fcntl module for the LOCK_EX constant.

my $writePos = 0;
while (<HDATFILE>){
	my $readPos = tell HDATFILE;

	if(m/^p11[016]/io){

	$found110 = 'y' unless m/^p110/i;
	$found111 = 'y' unless m/^p111/i;
	$found116 = 'y' unless m/^p116/i;

	seek HDATFILE, $writePos, 0;
	print HDATFILE &compareRmNames($fileName, $_);
	$writePos = tell HDATFILE;
	seek HDATFILE, $readPos, 0;

Unless you are writing the EXACT SAME NUMBER OF BYTES to the file, you are going to either over-write or under-write content.

You're probably better off using a temporary file, or Perl's "in-place" editing.

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