Most efficient way to write over file after reading
- by Ryan McClure
I'm reading in some data from a file, manipulating it, and then overwriting it to the same file. Until now, I've been doing it like so:
open (my $inFile, $file) or die "Could not open $file: $!";
$retString .= join ('', <$inFile>);
...
close ($inFile);
open (my $outFile, $file) or die "Could not open $file: $!";
print $outFile, $retString;
close ($inFile);
However I realized I can just use the truncate function and open the file for read/write:
open (my $inFile, '+<', $file) or die "Could not open $file: $!";
$retString .= join ('', <$inFile>);
...
truncate $inFile, 0;
print $inFile $retString;
close ($inFile);
I don't see any examples of this anywhere. It seems to work well, but am I doing it correctly? Is there a better way to do this?
