open F,$F or die "$F: $!";
my $prev;
my $this="";
+my $line;
while (<F>) {
+ $line=$.;
chomp;
if (!/^$/) {
$this.="$_\n";
local *TD;
my $td="diff -u $ta $tb|";
open TD,$td or die "$td: $!";
- <TD>=~/^\Q--- / or die $_;
- <TD>=~/^\Q+++ / or die $_;
+ <TD>=~/^\Q--- / or die "line $line: $_";
+ <TD>=~/^\Q+++ / or die "line $line: $_";
while (<TD>) {
next if /^[@ ]/;
print;