Write, Edit and Delete in a Text file

[Sanjib Sinha]

I want to add text to a file, getting it printed out in index.php and later want to edit/delete per row. I give codes page wise. first the form to take data:

add.php:

<?php
?>
<form method="post" action="add_data.php">
<fieldset>
<legend>Student List</legend>
Name : <input type="text" name="uname" /><br>
Content : <input type="text" name="age" />
<br>
<input type="submit" name="submit" value="send" />
</fieldset>
</form>

 

Next adding text to a file: add_data.php:

<?php
$id = 1;
if (file_exists("data.txt"))
{
$fp = fopen("data.txt", 'r');
$str = fread($fp, filesize("data.txt"));
$str_arr = explode("|", $str);
foreach ($str_arr as $rec)
{
	if ($rec)
	{
		$id++;
	}
}
}

$mode = (file_exists("data.txt"))? "a" : "w";

$fp = fopen("data.txt", $mode);
$line = $id . "--" . $_POST['uname'] . "--" . $_POST['age'] . "|";
$res = fwrite($fp, $line);
fclose($fp);

header("location:index.php");


?>

In the index.php, I'd like to fetch data and edit them per row:

<?php
$fp = fopen("data.txt", 'r');
$str = fread($fp, filesize("data.txt"));
$str_arr = explode("|", $str);
echo "<table border='1'>";
echo "<tr><td>ID</td><td>Name</td><td>Age</td><td>Option</td></tr>";

foreach ($str_arr as $rec)
{
	if ($rec)
	{
		$rec_arr = explode("--", $rec);
		echo "<tr>";
		foreach ($rec_arr as $col)
		{
			echo "<td>$col</td>";
		}
		print "<td><a href=\"edit.php?id=$id\">Edit</a>/<a href=\"delete.php?id=$id\">Delete</a></td></tr>";
	}
}
echo "</table>";

echo "<a href=\"add.php\">Add Data</a>";

?>

 

Next I want to Edit per row: edit.php:

<?php

$fp = fopen("data.txt", 'r');
$str = fread($fp, filesize("data.txt"));
$str_arr = explode("|", $str);

foreach ($str_arr as $rec)
{
if ($rec)
{
	$rec_arr = explode("--", $rec);		
	$id = $rec_arr[0];
	$name = $rec_arr[1];
	$age = $rec_arr[2];
	if ($id == $_REQUEST["id"])
	{
		echo "<form action='edit_data.php' method='post'>";
		echo "Name :<input type='text' name='uname' value='$name' /><br>";
		echo "Age: <input type='text' name='age' value=$age /><br>";
		echo "<input type='hidden' name='uid' value=$id />";
		echo "<input type='submit' value='Edit'>";
		echo "</form>";
	}		
}
}


?>

 

From edit.php to edit_data.php where I practically try to edit per row:

<?php

$fp = fopen("data.txt", 'r');
$str = fread($fp, filesize("data.txt"));
$str_arr = explode("|", $str);

foreach ($str_arr as $rec)
{
if ($rec)
{
	$rec_arr = explode("--", $rec);
	$id = $rec_arr[0];
	$name = $rec_arr[1];
	$age = $rec_arr[2];

	if ($id == $_POST['uid'])
	{
		$new_str = $id . "--" . $_POST['uname'] . "--" . $_POST['age'] . "|";
	}
	else 
	{
		$new_str = $id . "--" . $name . "--" . $age . "|"; 
	}
}
}

fclose($fp);

$fp = fopen("data.txt", 'w');
fwrite($fp, $new_str);
fclose($fp);


?>

 

The mechanism is simple. Taking datas from a form, explode them to an array and get them into col/row pattern to edit and delete them. But my problem is when I want to edit in index.php page, specially in this part:

print "<td><a href=\"edit.php?id=$id\">Edit</a>

It says, undefined index. But I try to catch this $id in the edit.php page, in this manner, as you see in my code:

foreach ($str_arr as $rec)
{
if ($rec)
{
	$rec_arr = explode("--", $rec);		
	$id = $rec_arr[0];
	$name = $rec_arr[1];
	$age = $rec_arr[2];
	if ($id == $_REQUEST["id"])
	{
		echo "<form action='edit_data.php' method='post'>";
		echo "Name :<input type='text' name='uname' value='$name' /><br>";
		echo "Age: <input type='text' name='age' value=$age /><br>";
		echo "<input type='hidden' name='uid' value=$id />";
		echo "<input type='submit' value='Edit'>";
		echo "</form>";
	}		
}
}

 

Have I done any mistake here? If anyone points out, I'll be obliged.