shell-ip-address(3)

NAME

ipv4_ip_subnet, ipv4_mask2prefix, ipv4_prefix2mask, valid_ipv4 - functions to validate the IPv4 address

SYNOPSIS

    • ipv4_ip_subnet ipaddr subnet
    • ipv4_mask2prefix value
    • ipv4_prefix2mask value
    • valid_ipv4 ipaddr

DESCRIPTION

  ipv4_ip_subnet
Function checks that IP address is in subnet.

Example:
    ipv4_ip_subnet 172.16.1.2 172.16.1.0/24; echo res=$?
    res=0
    ipv4_ip_subnet 172.16.3.2 172.16.1.0/24; echo res=$?
    res=1

  ipv4_mask2prefix
Function counts the leading 1 bits in the routing mask.

Example:
    ipv4_mask2prefix 255.255.0.0
    16
    ipv4_prefix2mask 255.255.255.0
    24

  ipv4_prefix2mask
Function converts routing prefix to netmask.

Example:
    ipv4_prefix2mask 16
    255.255.0.0
    ipv4_prefix2mask 24
    255.255.255.0

  valid_ipv4
Function checks that given option value is a valid IPv4 address.

ENVIRONMENT

regex_byte - Regexp for single octet in an IPv4 address.

regex_ipaddr - Regexp for 4-byte address.

regex_ipv4 - Regexp for IPv4 address (see <http://en.wikipedia.org/wiki/IP_address>). Some first-octet values have special meanings:

    • First octet 127 represents the local computer, regardless of what network it is really in. This is useful when testing internal operations.
    • First octet 224 and above are reserved for special purposes such as multicasting.

Octets 0 and 255 are not acceptable values in some situations, but 0 can be used as the second and/or third octet (e.g. 10.2.0.100).

AUTHOR
Authors and contributors of the programs included in the libshell package are listed in the COPYING file.

BUGS
Report bugs to the authors.