I've had to put up with that sort of loop lots of times -- yes, it has a klugy feel to it, but it still seems easier, simpler, clearer, etc, than alternatives, so I just live with it.

Other things can be done in general to streamline your code a little bit -- fewer variables, fewer lines of code, less open/close overhead on the temp file: 

open( DAT, '<', 'export.dat' )
    or die "Open for read failed on export.dat: $!";
my $tmp;  # file handle

while ( <DAT> ) {
    next unless ( /\S/ );
    if ( /^1/ ) {
        if ( defined( $tmp )) {
            output_data( $tmp );
        }
        open( $tmp, '+>', 'export.tmp' )  # open read/write, truncate 
+first
            or die "Open failed for export.tmp: $!";
    }
    print $tmp $_;
}
output_data( $tmp );

sub output_data
{
    my $fh = shift;
    seek( $fh, 0, 0 );  # rewind to start of file
    # do stuff with export.tmp contents...
    close $fh;
}

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In reply to Re: Ugly variable-length record handling by graff
in thread Ugly variable-length record handling by Melly

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