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Here's a quick and dirty way to use simple GMP functions with PHP without recompiling. It is dependent upon the use of the exec() function, so make sure you can use exec(). While in safe mode you must consider the safe_mode_exec_dir directive. And don't simply pass user input to the exec function without validating the input first!
Download and Install GMP as instructed in README and INSTALL files.
On my MAC OS X Server, I just did the following:
./configure
make
make check
make install
This installed it in the /usr/local directory. There were some errors, but not with any functions I needed.
Within the gmp-4.#.# cd into the demos directory. Then compile pexpr.c by typing:
make pexpr
This is a simple expressions parser which serves as a simple interface to some of the basic GMP functions.
You can test it then like:
./pexpr "102394874783 * 23498748";
Now you may interface with it using PHP's exec() function.
GMP Functions
简介
These functions allow you to work with arbitrary-length integers using the GNU MP library.
These functions have been added in PHP 4.0.4.
Note: Most GMP functions accept GMP number arguments, defined as resource below. However, most of these functions will also accept numeric and string arguments, given that it is possible to convert the latter to a number. Also, if there is a faster function that can operate on integer arguments, it would be used instead of the slower function when the supplied arguments are integers. This is done transparently, so the bottom line is that you can use integers in every function that expects GMP number. See also the gmp_init() function.
Warning
If you want to explicitly specify a large integer, specify it as a string. If you don't do that, PHP will interpret the integer-literal first, possibly resulting in loss of precision, even before GMP comes into play.
Note: This extension is available on Windows platforms since PHP 5.1.0.
需求
You can download the GMP library from » http://www.swox.com/gmp/. This site also has the GMP manual available.
You will need GMP version 2 or better to use these functions. Some functions may require more recent version of the GMP library.
安装
In order to have these functions available, you must compile PHP with GMP support by using the --with-gmp option.
运行时配置
本扩展模块在 php.ini 中未定义任何配置选项。
资源类型
Most GPM functions operate on or return GMP number resources.
预定义常量
以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。
范例
Example#1 Factorial function using GMP
<?php
function fact($x)
{
$return = 1;
for ($i=2; $i < $x; $i++) {
$return = gmp_mul($return, $i);
}
return $return;
}
echo gmp_strval(fact(1000)) . "\n";
?>
This will calculate factorial of 1000 (pretty big number) very fast.
参见
More mathematical functions can be found in the sections BCMath Arbitrary Precision Mathematics Functions and Mathematical Functions.
Table of Contents
- gmp_abs — Absolute value
- gmp_add — Add numbers
- gmp_and — Logical AND
- gmp_clrbit — Clear bit
- gmp_cmp — Compare numbers
- gmp_com — Calculates one's complement
- gmp_div_q — Divide numbers
- gmp_div_qr — Divide numbers and get quotient and remainder
- gmp_div_r — Remainder of the division of numbers
- gmp_div — 别名 gmp_div_q
- gmp_divexact — Exact division of numbers
- gmp_fact — Factorial
- gmp_gcd — Calculate GCD
- gmp_gcdext — Calculate GCD and multipliers
- gmp_hamdist — Hamming distance
- gmp_init — Create GMP number
- gmp_intval — Convert GMP number to integer
- gmp_invert — Inverse by modulo
- gmp_jacobi — Jacobi symbol
- gmp_legendre — Legendre symbol
- gmp_mod — Modulo operation
- gmp_mul — Multiply numbers
- gmp_neg — Negate number
- gmp_nextprime — Find next prime number
- gmp_or — Logical OR
- gmp_perfect_square — Perfect square check
- gmp_popcount — Population count
- gmp_pow — Raise number into power
- gmp_powm — Raise number into power with modulo
- gmp_prob_prime — Check if number is "probably prime"
- gmp_random — Random number
- gmp_scan0 — Scan for 0
- gmp_scan1 — Scan for 1
- gmp_setbit — Set bit
- gmp_sign — Sign of number
- gmp_sqrt — Calculate square root
- gmp_sqrtrem — Square root with remainder
- gmp_strval — Convert GMP number to string
- gmp_sub — Subtract numbers
- gmp_testbit — Tests if a bit is set
- gmp_xor — Logical XOR
add a note
User Contributed NotesGMP
john at worldmapad dot com
23-Jul-2006 02:24
23-Jul-2006 02:24
richard-slater.co.uk
22-Feb-2004 05:03
22-Feb-2004 05:03
For those (like me) who are trying to do bit masking with very large numbers, here is a useful function to do the work for you.
<?php
function isBitSet($bitMask, $bitMap)
{
return (bool) gmp_intval(gmp_div(gmp_and($bitMask, $bitMap),$bitMask));
}
?>
helvecio_oliveira at yahoo dot com dot br
16-Oct-2003 04:51
16-Oct-2003 04:51
=============================================================
A set of very nice functions to handle IP Address with gmplib:
The best way to store a range into a database is store:
dNet ..... decimal representation of a Net
dMask .... decimal representation of a Mask
All another parameters can be calculated.
<?
/*
f_ip2dec($a) ................... IP string to decimal
f_dec2ip($a) ................... decimal to IP string
f_dec2ipall($dNet,$dMask) ...... decimal Net and Mask to an Array with several IP parameters
f_dec2cidr($a) ................. decimal Mask to CIDR
f_and($a,$b) ................... and
f_or($a,$b) .................... or
f_xor($a,$b) ................... xor
f_not($a) ...................... not
f_dec2bin($a) .................. decimal to binary string
f_bin2dec($a) .................. binary string to decimal
*/
function f_and($a,$b){
$a=gmp_init(strval($a));
$b=gmp_init(strval($b));
$d=gmp_and($a,$b);
return floatval(gmp_strval($d));
}
function f_or($a,$b){
$a=gmp_init(strval($a));
$b=gmp_init(strval($b));
$d=gmp_or($a,$b);
return floatval(gmp_strval($d));
}
function f_xor($a,$b){
$a=gmp_init(strval($a));
$b=gmp_init(strval($b));
$d=gmp_xor($a,$b);
return floatval(gmp_strval($d));
}
function f_not($a){
$a=gmp_init(strval($a));
$d=gmp_strval($a,2);
$d=str_replace("1","x",$d);
$d=str_replace("0","1",$d);
$d=str_replace("x","0",$d);
$d=gmp_init($d,2);
return floatval(gmp_strval($d,10));
}
function f_dec2bin($a){
$a=gmp_init(strval($a));
return gmp_strval($a,2);
}
function f_bin2dec($a){
$a=gmp_init(strval($a),2);
return floatval(gmp_strval($a,10));
}
function f_ip2dec($a){
$d = 0.0;
$b = explode(".", $a,4);
for ($i = 0; $i < 4; $i++) {
$d *= 256.0;
$d += $b[$i];
};
return $d;
}
function f_dec2ip($a){
$b=array(0,0,0,0);
$c = 16777216.0;
$a += 0.0;
for ($i = 0; $i < 4; $i++) {
$k = (int) ($a / $c);
$a -= $c * $k;
$b[$i]= $k;
$c /=256.0;
};
$d=join('.', $b);
return($d);
}
function f_dec2cidr($a){
$a=gmp_init(strval($a));
$d=strlen(str_replace("0","",gmp_strval($a,2)));
return $d;
}
function f_dec2ipall($dNet,$dMask){
$dWildCard=f_not($dMask);
$IpAll["Net"]=f_dec2ip($dNet);
$IpAll["Mask"]=f_dec2ip($dMask);
$IpAll["WildCard"]=f_dec2ip($dWildCard);
$IpAll["Cidr"]=f_dec2cidr($dMask);
$IpAll["Bcast"]=f_dec2ip(f_or($dNet,$dWildCard));
$IpAll["nIp"]=$dWildCard+1;
$IpAll["nIpUtil"]=$dWildCard-1;
if($IpAll["nIp"] > 2){
$IpAll["IpFrom"]=f_dec2ip($dNet+1);
$IpAll["IpTo"]=f_dec2ip($dNet+$dWildCard-1);
}
else
{
$IpAll["IpFrom"]="-";
$IpAll["IpTo"]="-";
$IpAll["nIpUtil"]=0;
}
return $IpAll;
}
?>
=============================================================
GMP install steps in Mandrake 9.1:
----------------------------------------------------------
cp -r /usr/src/php-devel/extensions/gmp /tmp/gmp
cd /tmp/gmp
phpize
./configure
make install
echo "extension = gmp.so" > /etc/php/90_gmp.ini
Restart apache web server.
----------------------------------------------------------
gmp.so is in:
/usr/lib/php/extensions/
look in phpinfo, the string:
/etc/php/90_gmp.ini
Needs these tools:
autoconf
automake
libtool
m4
php430-devel-430-11mdk.rpm
all rpms that are envolved to run and compile gmp (*gmp*.rpm)
Some docs about self contained extensions:
/usr/share/doc/php430-devel-430/SELF-CONTAINED-EXTENSIONS
=============================================================