IP2LONG(3) 1 IP2LONG(3)ip2long - Converts a string containing an (IPv4) Internet Protocol dotted address into a proper addressSYNOPSIS
int ip2long (string $ip_address)
DESCRIPTION
The function ip2long(3) generates an IPv4 Internet network address from its Internet standard format (dotted string) representation.
ip2long(3) will also work with non-complete IP addresses. Read http://publibn.boul-
der.ibm.com/doc_link/en_US/a_doc_lib/libs/commtrf2/inet_addr.htm for more info.
PARAMETERS
o $ip_address
- A standard format address.
RETURN VALUES
Returns the IPv4 address or FALSE if $ip_address is invalid.
CHANGELOG
+--------+---------------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------------------------+
|5.2.10 | |
| | |
| | Prior to this version, ip2long(3) would some- |
| | times return a valid number even if passed an |
| | value which was not an (IPv4) Internet Protocol |
| | dotted address. |
| | |
+--------+---------------------------------------------------+
EXAMPLES
Example #1
ip2long(3) Example
<?php
$ip = gethostbyname('www.example.com');
$out = "The following URLs are equivalent:<br />
";
$out .= 'http://www.example.com/, http://' . $ip . '/, and http://' . sprintf("%u", ip2long($ip)) . "/<br />
";
echo $out;
?>
Example #2
Displaying an IP address
This second example shows how to print a converted address with the printf(3) function in both PHP 4 and PHP 5:
<?php
$ip = gethostbyname('www.example.com');
$long = ip2long($ip);
if ($long == -1 || $long === FALSE) {
echo 'Invalid IP, please try again';
} else {
echo $ip . "
"; // 192.0.34.166
echo $long . "
"; // -1073732954
printf("%u
", ip2long($ip)); // 3221234342
}
?>
NOTES
Note
Because PHP's integer type is signed, and many IP addresses will result in negative integers on 32-bit architectures, you need to
use the "%u" formatter of sprintf(3) or printf(3) to get the string representation of the unsigned IP address.
Note
ip2long(3) will return FALSE for the IP 255.255.255.255 in PHP 5 <= 5.0.2. It was fixed in PHP 5.0.3 where it returns -1 (same as
PHP 4).
SEE ALSO long2ip(3), sprintf(3).
PHP Documentation Group IP2LONG(3)
Check Out this Related Man Page
INET_ADDR(P) POSIX Programmer's Manual INET_ADDR(P)
NAME
inet_addr, inet_ntoa - IPv4 address manipulation
SYNOPSIS
#include <arpa/inet.h>
in_addr_t inet_addr(const char *cp);
char *inet_ntoa(struct in_addr in);
DESCRIPTION
The inet_addr() function shall convert the string pointed to by cp, in the standard IPv4 dotted decimal notation, to an integer value suit-
able for use as an Internet address.
The inet_ntoa() function shall convert the Internet host address specified by in to a string in the Internet standard dot notation.
The inet_ntoa() function need not be reentrant. A function that is not required to be reentrant is not required to be thread-safe.
All Internet addresses shall be returned in network order (bytes ordered from left to right).
Values specified using IPv4 dotted decimal notation take one of the following forms:
a.b.c.d
When four parts are specified, each shall be interpreted as a byte of data and assigned, from left to right, to the four bytes of an
Internet address.
a.b.c When a three-part address is specified, the last part shall be interpreted as a 16-bit quantity and placed in the rightmost two
bytes of the network address. This makes the three-part address format convenient for specifying Class B network addresses as
"128.net.host" .
a.b When a two-part address is supplied, the last part shall be interpreted as a 24-bit quantity and placed in the rightmost three bytes
of the network address. This makes the two-part address format convenient for specifying Class A network addresses as "net.host" .
a When only one part is given, the value shall be stored directly in the network address without any byte rearrangement.
All numbers supplied as parts in IPv4 dotted decimal notation may be decimal, octal, or hexadecimal, as specified in the ISO C standard
(that is, a leading 0x or 0X implies hexadecimal; otherwise, a leading '0' implies octal; otherwise, the number is interpreted as decimal).
RETURN VALUE
Upon successful completion, inet_addr() shall return the Internet address. Otherwise, it shall return ( in_addr_t)(-1).
The inet_ntoa() function shall return a pointer to the network address in Internet standard dot notation.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
The return value of inet_ntoa() may point to static data that may be overwritten by subsequent calls to inet_ntoa().
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
endhostent() , endnetent() , the Base Definitions volume of IEEE Std 1003.1-2001, <arpa/inet.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE
and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained
online at http://www.opengroup.org/unix/online.html .
IEEE /The Open Group 2003 INET_ADDR(P)