phpjs/experimental/filesystem/fgets.js

php.js offers community built php functions in javascript

function fgets(handle, length) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: fopen('http://kevin.vanzonneveld.net/pj_test_supportfile_1.htm', 'r');
  // *     example 1: fgets(handle, 1);
  // *     returns 1: '<'

  var start = 0,
      fullline = '',
      endlinePos = -1,
      content = '';

  if (!this.php_js || !this.php_js.resourceData || !this.php_js.resourceDataPointer || length !== undefined && !length) {
    return false;
  }

  start = this.php_js.resourceDataPointer[handle.id];

  if (start === undefined || !this.php_js.resourceData[handle.id][start]) {
    return false; // Resource was already closed or already reached the end of the file
  }

  content = this.php_js.resourceData[handle.id].slice(start);

  endlinePos = content.search(/\r\n?|\n/) + start + 1;
  fullline = this.php_js.resourceData[handle.id].slice(start, endlinePos + 1);
  if (fullline === '') {
    fullline = this.php_js.resourceData[handle.id].slice(start); // Get to rest of the file
  }

  length = (length === undefined || fullline.length < length) ? fullline.length : Math.floor(length / 2) || 1; // two bytes per character (or surrogate), but ensure at least one

  this.php_js.resourceDataPointer[handle.id] += length;
  return this.php_js.resourceData[handle.id].substr(start, length);
}