SYNOPSIS

grepcidr [-V] [-c] [-v] [-e pattern | -f file]

DESCRIPTION

This manual page documents briefly the grepcidr command.

This manual page was written for the Debian distribution because the original program does not have a manual page.

grepcidr can be used to filter a list of IP addresses against one or more Classless Inter-Domain Routing (CIDR) specifications, or arbitrary networks specified by an address range. As with grep, there are options to invert matching and load patterns from a file. grepcidr is capable of comparing thousands or even millions of IPs to networks with little memory usage and in reasonable computation time.

OPTIONS

-V

Show software version

-c

Display count of the matching lines, instead of showing the lines

-v

Invert the sense of matching, to select non-matching IP addresses

-e

Specify pattern(s) on command-line

-f

Obtain CIDR and range pattern(s) from file

EXAMPLES

grepcidr -f ournetworks blocklist > abuse.log

Find our customers that show up in blocklists

grepcidr 127.0.0.0/8 iplog

Searches for any localnet IP addresses inside the iplog file

grepcidr "192.168.0.1-192.168.10.13" iplog

Searches for IPs matching indicated range in the iplog file

script | grepcidr -vf whitelist > blacklist

Create a blacklist, with whitelisted networks removed (inverse)

grepcidr -f list1 list2

Cross-reference two lists, outputs IPs common to both lists

AUTHOR

This manual page was written by Ryan Finnie [email protected] for the Debian system (but may be used by others). Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 any later version published by the Free Software Foundation.

On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL.