将字符串添加到文件的特定行之后

已经有很长一段时间了，但对于将来遇到这种情况的任何人都很有用…

$f = fopen("path/to/file", "r+");
$oldstr = file_get_contents("path/to/file");
$str_to_insert = "Write the string to insert here";
$specificLine = "Specify the line here";

// read lines with fgets() until you have reached the right one
//insert the line and than write in the file.

while (($buffer = fgets($f)) !== false) {
    if (strpos($buffer, $specificLine) !== false) {
        $pos = ftell($f); 
        $newstr = substr_replace($oldstr, $str_to_insert, $pos, 0);
        file_put_contents("path/to/file", $newstr);
        break;
    }
}
fclose($f);

这是一种方法，有点冗长，但使所有修改都内联:

$f = fopen("test.txt", "tr+");
// read lines with fgets() until you have reached the right one
$pos = ftell($f);                   // save current position
$trailer = stream_get_contents($f); // read trailing data
fseek($f, $pos);                    // go back
ftruncate($f, $pos);                // truncate the file at current position
fputs($f, "my strings'n");          // add line
fwrite($f, $trailer);               // restore trailing data

如果文件特别大，则需要一个中间文件

还有一种方法是使用file()函数。In返回特定文件每行内容的数组。从那里，您可以操作数组并将该值附加到特定的行上。考虑这个例子:

// Sample file content (original)
// line 1
// line 2
// line 3
// line 4
// line 5
// line 6

$replacement = "Hello World";
$specific_line = 3; // sample value squeeze it on this line
$contents = file('file.txt', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
if($specific_line > sizeof($contents)) {
    $specific_line = sizeof($contents) + 1;
}
array_splice($contents, $specific_line-1, 0, array($replacement)); // arrays start at zero index
$contents = implode("'n", $contents);
file_put_contents('file.txt', $contents);
// Sample output
// line 1
// line 2
// Hello World
// line 3
// line 4
// line 5
// line 6

下面是我的代码

 function doit($search,$file,$insert)
{
$array = explode("'n", file_get_contents($file));
$max=count($array);
for($a=0;$a<$max;$a++)
{if($array[$a]==$search) {
$array = array_slice($array, 0, $a+1, true) +
array($insert) +
array_slice($array, $a+1);
 break;}}
 $myfile = fopen($file, "w");
 $max=count($array);
 var str='';
 for($a=0;$a<$max;$a++)
 {str.=$array[$a].''n';}
 fclose($myfile);
 }

您必须提供文件路径($file)，新行文本($insert)和行文本($search)，之后将插入新行