'Return value of "open" ignored at line 188, column 3.  Check the return value of "open" for success.  (Severity: 3)'
'Readline inside "for" loop at line 51, column 16.  See page 211 of PBP.  (Severity: 4)'
'Bareword file handle opened at line 120, column 2.  See pages 202,204 of PBP.  (Severity: 5)',
'Two-argument "open" used at line 120, column 2.  See page 207 of PBP.  (Severity: 5)',
'Two-argument "open" used at line 188, column 3.  See page 207 of PBP.  (Severity: 5)'

##</code><code>##

=head1 Info

 Script to search text for ip address on a given subnet
 Subnet can be specified as x.x.x.x/x.x.x.x or x.x.x.x/xx
 Options are similar to grep:
     -c count matching lines
     -v select lines which do not match
     -f <pattern file> containing one subnet in the form above per line
 Example: ./subnet-grep.pl 10.5.1.0/24 /etc/hosts
 Example: ./subnet-grep.pl -c 192.168.1.0/255.255.255.0 input1.txt input2.txt

=cut

##</code><code>##

perldoc subnet-grep.pl