Ack doesn't search zero length files

[bitsed]

Some operating systems (notably Linux) provide zero length files containing system information. Ack version 1.90 doesn't work with these files since it skips searching of all zero length files. The patch below attempts to address this issue.

--- /usr/bin/ack        2009-10-19 11:14:59.919362762 -0700
+++ bin/ack     2009-10-19 11:57:05.632362838 -0700        
@@ -2481,21 +2481,24 @@                                    
                                                           
     return 1 if $opt->{v};                                

-    my $size = -s $self->{fh};
-    if ( $size == 0 ) {
-        return 0;
-    }
-    elsif ( $size > 100_000 ) {
-        return 1;
+    if ( -s $self->{fh} > 100_000 ) {
+       return 1;
     }

     my $buffer;
-    my $rc = sysread( $self->{fh}, $buffer, $size );
+    my $size;
+    my $rc;
+    do {
+        my $inbuf;
+        $size += $rc = sysread( $self->{fh}, $inbuf, 100_000 );
+        $buffer .= $inbuf;
+    } while ($rc != 0);
+
     if ( not defined $rc ) {
         App::Ack::warn( "$self->{filename}: $!" );
         return 1;
     }
-    return 0 unless $rc && ( $rc == $size );
+    return 0 unless $size;

     my $regex = $opt->{regex};
     return $buffer =~ /$regex/m;

[petdance]

I don't understand why it would be bad to not search 0-length files.

[bitsed]

I think it's not searching zero length files that don't match.

[bitsed]

This issue looks like it's a duplicate of issue 89.

[hoelzro]

Closing as duplicate of #89.