.TH "GREPCIDR" "1" 
.SH "NAME" 
grepcidr \(em Filter IP addresses matching IPv4 CIDR/network specification 
.SH "SYNOPSIS" 
.PP 
\fBgrepcidr\fR [\fB-V\fP]  [\fB-c\fP]  [\fB-v\fP]  [\fB-e \fIpattern\fR\fP | \fB-f \fIfile\fR\fP]  
.SH "DESCRIPTION" 
.PP 
This manual page documents briefly the \fBgrepcidr\fR command. 
.PP 
This manual page was written for the \fBDebian\fP distribution 
because the original program does not have a manual page. 
.PP 
\fBgrepcidr\fR 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. 
.SH "OPTIONS" 
.IP "\fB-V\fP" 10 
Show software version 
.IP "\fB-c\fP" 10 
Display count of the matching lines, instead of showing the lines 
.IP "\fB-v\fP" 10 
Invert the sense of matching, to select non-matching IP addresses 
.IP "\fB-e\fP" 10 
Specify pattern(s) on command-line 
.IP "\fB-f\fP" 10 
Obtain CIDR and range pattern(s) from file 
.SH "EXAMPLES" 
.PP 
\fI\fBgrepcidr\fP \-f ournetworks blocklist > abuse.log\fP 
.PP 
Find our customers that show up in blocklists 
.PP 
\fI\fBgrepcidr\fP 127.0.0.0/8 iplog\fP 
.PP 
Searches for any localnet IP addresses inside the iplog file 
.PP 
\fI\fBgrepcidr\fP "192.168.0.1-192.168.10.13" iplog\fP 
.PP 
Searches for IPs matching indicated range in the iplog file 
.PP 
\fI\fBscript\fP | \fBgrepcidr\fP \-vf whitelist > blacklist\fP 
.PP 
Create a blacklist, with whitelisted networks removed (inverse) 
.PP 
\fI\fBgrepcidr\fP \-f list1 list2\fP 
.PP 
Cross-reference two lists, outputs IPs common to both lists 
.SH "AUTHOR" 
.PP 
This manual page was written by Ryan Finnie ryan@finnie.org for 
the \fBDebian\fP 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. 
 
.PP 
On Debian systems, the complete text of the GNU General Public 
License can be found in /usr/share/common-licenses/GPL. 
 
.\" created by instant / docbook-to-man, Sun 04 Sep 2011, 13:49