PHP和Javascript：使用Javascript变量获取文件内容

Question

Could someone help me to understand why this isn't working?

var uname = "<?php echo strtolower($_GET['un']) ?>";
var source = "<?php echo file_get_contents('accounts/"+uname+"') ?>";
console.log(source);

I've been trying for a while to get this working and it just doesn't seem to. Before I added in the source variable, it was working fine and displayed the un variable on the page.

Thanks.

Answer 1

You are mixing client side and server side technologies... +uname+ looks like a JavaScript variable within a PHP command... The JavaScript variable isn't available until the page is rendered.

Try...

var source = "<?php echo file_get_contents('accounts/'. $_GET['un']) ?>";

Answer 2

You set uname as a javascript variable and then you try to read it with php.

var source = "<?php echo file_get_contents('accounts/'.strtolower($_GET['un'])) ?>";
console.log(source);

I must say that this is not safe for a public usage in anyway.

Answer 3

I just want to point out that you don't need PHP to access variables in your query string, as some already mentioned, you are mixing technologies here. Also note that your questions example has security issues and I'm pretty sure that these will persist as you need to sanitize the input in the script you call!

Your complete example can be done in javascript. I'll use jQuery for the ajax call (you can omit it ofc and handle the ajax call yourself obviously - I'm just being lazy ;-) ) and an MDN snippte for query string retrieval.

// populate a variable with your query string (window.location.search) - courtesy of MDN
var oGetVars = new (function (sSearch) {
  var rNull = /^\s*$/, rBool = /^(true|false)$/i;
  function buildValue(sValue) {
    if (rNull.test(sValue)) { return null; }
    if (rBool.test(sValue)) { return sValue.toLowerCase() === "true"; }
    if (isFinite(sValue)) { return parseFloat(sValue); }
    if (isFinite(Date.parse(sValue))) { return new Date(sValue); }
    return sValue;
  }
  if (sSearch.length > 1) {
    for (var aItKey, nKeyId = 0, aCouples = sSearch.substr(1).split("&"); nKeyId < aCouples.length; nKeyId++) {
      aItKey = aCouples[nKeyId].split("=");
      this[unescape(aItKey[0])] = aItKey.length > 1 ? buildValue(unescape(aItKey[1])) : null;
    }
  }
})(window.location.search);

// with jQuery
$.ajax({
    url: "accounts/" + oGetVars.un,
    success: function(data, textStatus, jqXHR) {
        console.log(data);
    }
});

// plain javascript
var xhr = new XMLHttpRequest();
xhr.open("GET", "accounts/" + oGetVars.un, true);
xhr.onreadystatechange = function () {
    if(http.readyState == 4 && http.status == 200) {
        console.log(this.responseText);
    }
};
xhr.send();

[edit] Update the example with a plain javascript XMLHttpRequest call.

Answer 4

Try this:

<?php $uname = strtolower($_GET['un']); ?>
var source = "<?php echo file_get_contents('accounts/'.$uname) ?>";