The interchange function of gb2312 and utf-8 without Iconv library

The function of a copy of Gb2312.txt (184799 bytes) does appear to be a bit too large and is also converted by Unicode.
This table is 51965 bytes, much smaller.
It is also useful for situations where the ICONV function library cannot be used.

<?php
Use of the comparison table
$filename = "Gb2utf8.txt";
$fp = fopen ($filename, "R");
while (! feof ($fp)) {
List ($GB, $utf 8) = Fgetcsv ($fp, 10);
$charset [$GB] = $utf 8;
}
Fclose ($FP);
Read the comparison table above to the array standby

/** gb2312 to Utf-8 **/
function Gb2utf8 ($text, & $charset) {
Extracts the composition of the text, the Chinese character is an element, the continuous non-Chinese character is an element
Preg_match_all ("/(?: [\x80-\xff].) | [\x01-\x7f]+/", $text, $tmp);
$tmp = $tmp [0];
The separation of Chinese characters
$ar = Array_intersect ($tmp, Array_keys ($charset));
Replace encoding
foreach ($ar as $k => $v)
$tmp [$k] = $charset [$v];
Returns the string after the code change
Return join (", $tmp);
}

/** Utf-8 to gb2312 **/
function UTF82GB ($text, & $charset) {
$p = "/[xf0-xf7][x80-xbf]{3}| [Xe0-xef] [X80-XBF] {2}| [XC2-XDF] [x80-xbf]| [x01-x7f]+/];
Preg_match_all ($p, $text, $r);
$utf 8 = Array_flip ($charset);
foreach ($r [0] as $k => $v)
if (Isset ($utf 8[$v]))
$r [0][$k] = $utf 8[$v];
Return join (', $r [0]);
}

Test
$s = Gb2utf8 (' This is the test of the comparison table ', $charset);
Echo utf82gb ($s, $charset);
?>