Q:

How to edit/update a txt file with php

After I've read a lot of similar problems with the edit/update function on a file and none of it worked I would like to ask for some help.
I am trying to edit a .txt document from php. I have tried these things:

This was the last code which I've read here and didn't work.
$data_to_write = "$_POST[subject]";
$file_path = "text/" + $row['name'];
$file_handle = fopen($file_path, 'w'); 
fwrite($file_handle, $data_to_write);
fclose($file_handle);

And this is my previous try:
$new_contents = "$_POST[subject]\n";
$path = "text/$row[name]";
file_put_contents($path, $new_contents);

I hope someone would explain me how to do this the right way. Thank you.
This is all of my code: 
<?php
if(isset($_GET['id']))
{
$edit = mysql_query("SELECT * FROM text_area WHERE text_id=$_GET[id]");
$row = mysql_fetch_assoc($edit);
$contents = file_get_contents($row['content']);
?>
<form action="" name="form" method="post">
<input type="hidden" name="id" value="<?php echo $row['text_id']; ?>" /><br />
<label for="">Заглавие:</label><br />
<input type="text" name="title" style="width:500px;" value="<?php echo $row['subject'] ?>" /><br />
<select name="opt">
<option value="0"></option>
<?php

$result = mysql_query("SELECT * FROM image_area");
while ($row = mysql_fetch_array($result))
{
        echo "<option value=" . $row['path'] . ">" . $row['name'] . "</option>
            ";  
    }

?>
</select><input type="button" name="sumbitP" value="Choose" onclick="addtext();" /><a href="../image_list.php" target="_blank">Image list</a><br />
<textarea rows="10" cols="50" name="text" id="markItUp"><?php echo $contents ?></textarea><br />
<input type="submit" name="sumbitT" value="Update" />
<input type="reset" value="Reset" />

</form>
<?php
}
?>
<?php

if(isset($_POST['id']))
{
    if(mysql_query("UPDATE text_area SET title='$_POST[subject]' WHERE text_id ='$_POST[id]'"))
    {

$data_to_write = "" . $_POST['text'];
$file_path = "text/$row[name]";
$file_handle = fopen($file_path, 'w');
fwrite($file_handle, $data_to_write);
fclose($file_handle);

        echo '<br><br><p align="center">Everything is ok</p>';
    } else {
        echo '<br><br><p align="center">Everything is not ok</p>' ;
    }
?>

Just to add something which might be useful:  I am getting this error which I can't manage to find an answer for with Google. 
Warning: fopen(text/) [function.fopen]: failed to open stream: Is a directory in

A:

You just need to change :
$file_path = "text/" + $row['name'];

to this :
$file_path = "text/" . $row['name'];

The concatenation operator in PHP is . (not +)
And make sure the directory text exists, otherwise its better to check and then write :
$data_to_write = $_POST['subject'];
$file_path = "text/" . $row['name'];

if ( !file_exists("text") )
    mkdir("text");

$file_handle = fopen($file_path, 'w'); 
fwrite($file_handle, $data_to_write);
fclose($file_handle);

A:

You can also open file in append mode using fopen() and put whatever you have at the end like
$path = dirname(__FILE__).'/newfile.txt';
$fp = fopen($path, 'a');
if(!$fp){
echo 'file is not opend';
}
fwrite($fp, 'this is simple text written');
fclose($fp);

Detail is mentioned in TechFlirt File Handling Blog here

A:

You need to use file_get_contents to get the text of your file.
$file_path= "text/" . $row['name'];
// Open the file to get existing content
$current = file_get_contents($file_path);
// Append a new person to the file

$data_to_write.= $_POST[subject]."\n";
// Write the contents back to the file
file_put_contents($file_path, $data_to_write);

See Documentation

