I think it's no longer necessary to worry about trailing nulls. This was fixed in Feb 2002 (see bug 10133)
gmp_strval
(PHP 4 >= 4.0.4, PHP 5)
gmp_strval — GMP 数を文字列に変換する
説明
string gmp_strval ( resource gmpnumber [, int base] )GMP 数を base を基数とする文字列表現に 変換します。デフォルトの基数は 10 です。基数として使用可能な値は 2 から 36 までです。
例 760. GMP 数を文字列に変換する
<?php
$a = gmp_init("0x41682179fbf5");
printf("10 進数: %s, 36 進数: %s", gmp_strval($a), gmp_strval($a,36));
?>
gmp_strval
php at richardneill dot org
20-Sep-2006 08:47
20-Sep-2006 08:47
caldwell at utm dot NoSpamPlease dot edu
23-Jul-2001 12:17
23-Jul-2001 12:17
Warning: gmp_strval may return a null terminated string (e.g., gmp_strval(gmp_init(8)) has two characters. This is because gmp is built for speed, so uses estimates based on things it can get quickly, like the number of bits in N. So since 8 is a 4 bit number, it will be allocated ceil(log10(2^4))=ceil(4*0.30103....) = 2 characters. The gmp folks feel it is the caller's responsibility (in this case the PHP interface) to check whether or not all the characters were required. PHP might have done this for us (and may in the future), but for now, you need to check (if it matters to you--it sure did in my program!).