用php替换文本文件中的值答案

【问题标题】：Replace valuie in text file with php用php替换文本文件中的值
【发布时间】：2017-08-01 09:58:32
【问题描述】：

我有一个具有以下设计的文本文件：

约翰·史密斯|1|john@smith.com|nopassword|admin
汤姆·史密斯|3|tom@smith.com|admin123|用户
....

等等。每个字段都由“|”分隔。我需要做的是替换值，例如此文本文件中用户的密码或帐户类型。

汤姆·史密斯|5|tom@smith.com|admin1234|admin

我成功找到了该行并使用explode() 将其吐出，但是如何修改该值并将其写回到文本文件中？

$name = $_POST['name'];
$mydb = file('./DB/users.txt');
foreach($mydb as $line) {
    if(stristr($line,$name)) $pieces = explode("|", $line);
    $position = str_replace(array("\r\n","\r"),"",$pieces[1]);
    $email = str_replace(array("\r\n","\r"),"",$pieces[2]);
    $password = str_replace(array("\r\n","\r"),"",$pieces[3]);
    $atype = str_replace(array("\r\n","\r"),"",$pieces[4]);

【问题讨论】：

你能把你现有的代码放在这里吗？
您是要全部修改，还是只修改一个？
另外，您是否考虑过使用数据库？这看起来更像是数据库的工作。
$name = $_POST['name']; $mydb = file('./DB/users.txt'); foreach($mydb as $line) { if(stristr($line,$name)) $pieces = explode("|", $line); $position = str_replace(array("\r\n","\r"),"",$pieces[1]); $email = str_replace(array("\r\n","\r"),"",$pieces[2]); $password = str_replace(array("\r\n","\r"),"",$pieces[3]); $atype = str_replace(array("\r\n","\r"),"",$pieces[4]); }
一个数据库没关系，但这更容易使应用程序在工作中具有可移植性。

标签： php string file text replace

【解决方案1】：

有多种方法可以做到这一点。这是一种方法。我评论了代码以解释它是如何工作的。

$name = $_POST['name'];

// use FILE_IGNORE_NEW_LINES so you won't have to deal with the line breaks
$mydb = file('./DB/users.txt', FILE_IGNORE_NEW_LINES);

// use a reference (&$line) so the code in your foreach loop modifies the $mydb array
foreach ($mydb as &$line) {
    if (stristr($line,$name)) {

        // assign the elements of the row to variables
        list($name, $number, $email, $password, $type) = explode('|', $line);

        // change whatever you need to change
        $password = 'new password';
        $type = 'new type';

        // overwrite the line with the modified values
        $line = implode('|', [$name, $number, $email, $password, $type]);

        // optional: break out of the loop if you only want to do the replacement
        // for the first item found that matches $_POST['name']
        break;
    }
};

// overwrite the file after the loop
file_put_contents('./DB/users.txt',  implode("\n", $mydb));

【讨论】：

【解决方案2】：

PHP 提供了读取、写入和附加到文件的选项。

您需要打开文件，读取所有内容，然后覆盖文件。您将使用追加获得重复的条目。

这是来自https://www.w3schools.com/php/php_file_create.asp的示例代码：

<?php
  $myfile = fopen("newfile.txt", "w") or die("Unable to open file!");
  $txt = "John Doe\n";
  fwrite($myfile, $txt);
  $txt = "Jane Doe\n";
  fwrite($myfile, $txt);
  fclose($myfile);
?>

对于您的代码：

<?php
  $name = $_POST['name'];
  $mydb = file('./DB/users.txt'); 

  $output = array();
  foreach($mydb as $line) { 
    if(stristr($line,$name)) {
      $pieces = explode("|", $line); 
      $position = str_replace(array("\r\n","\r"),"",$pieces[1]); 
      $email = str_replace(array("\r\n","\r"),"",$pieces[2]); 
      $password = str_replace(array("\r\n","\r"),"",$pieces[3]); 
      $atype = str_replace(array("\r\n","\r"),"",$pieces[4]); 

      // Glue the variables back together and overwrite $line so that it gets up in the array
      $line = $name & "|" $position & "|" $email & "|" $password & "|" $atype & "\r";
    }
    // put everything in the $output array so that it can be writen to file after this loop
    array_push($output, $line);
  }
  fclose($mydb);

  // Write your output to file
  $mydb = fopen('./DB/users.txt', "w") or die("Unable to open file!");
  foreach($output as $line) { 
    fwrite($mydb, $line);
  }
  fclose($mydb);
?>

【讨论】：