libcidr — CIDR-style IP address manipulation functions

libcidr  is  written and maintained by Matthew Fuller ⟨fullermd@over-yonder.net⟩.  Its home on the web is
       at  ⟨http://www.over-yonder.net/~fullermd/projects/libcidr⟩;  check  there  for  updates  and  additional
       documentation.

Debian                                             May 7, 2012                                        libcidr(3)

CIDR*cidr_addr_broadcast(constCIDR*cidr)
             Return a CIDR structure describing the broadcast address of the network represented by cidr.

       CIDR*cidr_addr_hostmax(constCIDR*cidr)
             Return a CIDR structure describing the "highest" host in the subnet represented by cidr.

       CIDR*cidr_addr_hostmin(constCIDR*cidr)
             Return a CIDR structure describing the "lowest" host in the subnet represented by cidr.

       CIDR*cidr_addr_network(constCIDR*cidr)
             Return a CIDR structure describing the network address of the network represented by cidr.

       CIDR*cidr_alloc(void)
             Allocate and initialize a CIDR structure.

       intcidr_contains(constCIDR*big,constCIDR*little)
             Determine  whether  little  is  a  CIDR block entirely contained within the block described by big.
             Return 0 if so, else non-zero.

       CIDR*cidr_dup(constCIDR*cidr)
             Return a duplicate of cidr.

       intcidr_equals(constCIDR*first,constCIDR*second)
             Determine whether first and second describe the same CIDR block.  Return 0 if they  do,  else  non-
             zero.

       voidcidr_free(CIDR*cidr)
             Free the memory used by a CIDR*.

       CIDR*cidr_from_inaddr(conststructin_addr*in)
             Generate a CIDR* based on a structin_addr.

       CIDR*cidr_from_in6addr(conststructin6_addr*in)
             Generate a CIDR* based on a structin6_addr.

       CIDR*cidr_from_str(constchar*str)
             Parse str and return a CIDR* representing it.

       uint8_t*cidr_get_addr(constCIDR*cidr)
             Return the address in an array of binary octets.

       uint8_t*cidr_get_mask(constCIDR*cidr)
             Return the netmask in an array of binary octets.

       intcidr_get_pflen(constCIDR*cidr)
             Return the length of the netmask prefix of cidr.

       intcidr_get_proto(constCIDR*cidr)
             Return the protocol of an address.

       intcidr_is_v4mapped(constCIDR*addr)
             Checks if an IPv6 address is in the IPv4-mapped range.

       CIDR**cidr_net_subnets(constCIDR*cidr)
             Return  a  2-element  array  of  CIDR*'s  representing the two immediate subnets of the network
             described by cidr.  That is to say, the two networks, within cidr,  which  have  a  netmask  1  bit
             longer.

       CIDR*cidr_net_supernet(constCIDR*cidr)
             Return a CIDR* describing the "parent" network of cidr.  That is, the network with a netmask 1 bit
             shorter, which wholly contains cidr.

       constchar*cidr_numaddr(constCIDR*cidr)
             Return  a  pointer to a static string giving the number of total addresses available in the network
             described by cidr.  Do not attempt to alter or free(3) this string.

       constchar*cidr_numaddr_pflen(intpflen)
             Return a pointer to a static string giving the number of total addresses  available  in  a  network
             having  a  prefix  length  of pflen.  Do not attempt to alter or free(3) this string.  You probably
             don't want to call this function manually often.

       constchar*cidr_numhost(constCIDR*cidr)
             Return a pointer to a static string giving the number of addresses available for hosts available in
             the network described by cidr.  Do not attempt to alter or free(3) this string.

       constchar*cidr_numhost_pflen(intpflen)
             Return a pointer to a static string giving the number of addresses available for hosts in a network
             having a prefix length of pflen.  Do not attempt to alter or free(3)  this  string.   You  probably
             don't want to call this function manually often.

       structin_addr*cidr_to_inaddr(constCIDR*cidr,structin_addr*in)
             Fill in a structin_addr with the address given in cidr.  A user-supplied structin_addr is used if
             passed in; if a null pointer is passed, a new one will be allocated, filled in, and returned.

       structin6_addr*cidr_to_in6addr(constCIDR*cidr,structin6_addr*in)
             Fill  in a structin6_addr with the address given in cidr.  A user-supplied structin6_addr is used
             if passed in; if a null pointer is passed, a new one will be allocated, filled in, and returned.

       char*cidr_to_str(constCIDR*cidr,intflags)
             Return a string version of the passed-in cidr, as described by flags.  By default, it will print in
             the standard address form for whatever address family cidr represents, followed  by  a  slash,  and
             then the prefix length of the netmask.

       constchar*cidr_version(void)
             Return a static string containing version information.

       libcidr — CIDR-style IP address manipulation functions

libcidr  is a C library implementing a variety of functions to manipulate IP addresses and netblocks.  It
       handles both IPv4 and IPv6 networks, will transform them to  and  from  text  strings  in  a  variety  of
       formats,  cram them into and lever them out of in_addr and in6_addr structures, and give you all sorts of
       stats about them.  Functions are provided also to tell you a few things about the network any given  CIDR
       block  is in, what its parent and child networks are, and so on.  If you're really nice, libcidr may even
       cook you breakfast.

       The primary documentation for libcidr is maintained elsewhere, with a full description of the  functions,
       their  options,  and  their return values.  Your installation probably has a copy of the reference manual
       installed somewhere, perhaps in /usr/share/libcidr/docs.  Documentation is also available on the  webpage
       (see below).  This manpage is provided as a quick reference.

#include<libcidr.h>
       Library libcidr (-lcidr)