saving to text file with submit button - php

Question

I have this code that displays contents of a particular file. I would like to add a submit button that when clicked saves the changes in to a file. Can anyone help me or give some examples that i can use to create this button. i have tried couple of example that i found on the web but could get it to work. is the solution hidden somewhere with $_POST. her is the code.
<?php
$relPath = 'test_file_1.php';
$fileHandle = fopen($relPath, 'r') or die("Failed to open file $relPath go and make me a sandwich! "); ;
while(!feof($fileHandle)){
$line = fgets($fileHandle);
$lineArr = explode('=', $line);
if (count($lineArr) !=2){
continue;
}
$part1 = trim($lineArr[0]);
$part2 = trim($lineArr[1]);
$simbols = array("$", "[", "]", "'", ";");
//echo "<pre>$part1 $part2</pre>";
echo '<form>
<pre><input type="text" name="content_prt1" size="50" value="' .str_replace($simbols, "",$part1).'"> <input type="text" name="content_prt2" size="50" value="' .str_replace($simbols, "",$part2).'"></pre>
<form />';
}
echo '<input type="submit" value="Submit">';
fclose($fileHandle) or die ("Error closing file!");
?>
EDIT
code for the updatefile.php
<?php
if(isset($_REQUEST['submit1'])){
$handle = fopen("test_file_1.php", "a") or die ("Error opening file!");;
$file_contents = $_REQUEST["content_prt1" . "content_prt1"];
fwrite($handle, $file_contents);
fclose($handle);
}
?>
the code stops at error opening file

Answer 1

If you look at the at purely submitting point of view then put the submit button inside the <form> tags
Also, the closing form tags must be form and not from. The updatefile.php I refer to is the file that you post the input box type text to that will update the file of the database field. Remember to close the file before writing to it again. Hope this helps.
<?php
$relPath = 'test_file_1.php';
$fileHandle = fopen($relPath, 'r') or die("Failed to open file $relPath go and make me a sandwich! ");
echo '<form action="updatefile.php" method="POST">';
while(!feof($fileHandle))
{
$line = fgets($fileHandle);
$lineArr = explode('=', $line);
if (count($lineArr) !=2){
continue;
}
$part1 = trim($lineArr[0]);
$part2 = trim($lineArr[1]);
$vowels = array("$", "[", "]", "'", ";");
echo '<pre><input type="text" name="content_prt1" size="50" value="' .str_replace($vowels, "",$part1).'">
<input type="text" name="content_prt2" size="50" value="' .str_replace($vowels, "",$part2).'">
</pre>';
}
echo '<input type="submit" value="Submit">';
echo '<form>';
fclose($fileHandle) or die ("Error closing file!");
?>

Answer 2

You can't submit more than one form with a single submit button. You'll have to echo the <form> tags outside of the loop so that only one form gets created.
The other problem is you have multiple inputs that are named the same, so $_POST will contain only the value of the last input of each name. You probably mean to append [] to the names of the inputs, e.g. name="content_prt1[]". This way, PHP will create an array of those inputs' values in $_POST['content_prt1'].
Finally, note that what you have so far may pose an HTML injection risk (when displaying the page) unless you're certain that the text coming out of the file doesn't contain characters like < and >. To mitigate this, you can use htmlentities when echoing the text into the inputs.