Php sample code for intercepting n characters starting at a certain position in the GBK document

The following is a small compilation of the n-character method for intercepting a GBK document by using php at a certain position. I think this is quite good. now I will share it with you and give you a reference. Let's take a look at the following small series to bring you a php method to intercept the GBK document at a certain position starting with n characters. I think this is quite good. now I will share it with you and give you a reference. Let's take a look at it with Xiaobian.

Cut. php:

#!/usr/bin/php
 = $file_size) exit;$fp = fopen(INPUT_FILE, 'rb');$point = 0; //current byte position$string = ''; while(ftell($fp) < $file_size) {  if($point >= $pos + $len) break;$byte = fread($fp, 1);   //php version >= 5.4  $char = unpack('C', $byte)[1];  if($char <= 0x7f) {    //single byte    if($point >= $pos) $string .= $byte;    $point += 1;    continue;  } else {    //double bytes    if($point >= $pos) {      $string .= $byte.fread($fp, 1);     } else {      fseek($fp, 1, SEEK_CUR);    }    $point += 1;    continue;  }  }fclose($fp);file_put_contents(OUTPUT_FILE, $string);?>

SOURCE file t.txt content:

Dkei20 Wang nnso

Test Command:

./cut.php 6 1

View results:

hexdump -C t.txt && hexdump -C a.txt

The above is a detailed description of the sample code for php to capture the n characters starting at a certain position in the GBK document. For more information, see other related articles in the first PHP community!