PHP How to delete a specific line in a text file using user input?

Question

A user selects a number "$Num = $_POST['Number']" from a drop down to delete a line from a text file. Ex.

Cat
Dog
Mouse

Lets say they chose line 3. How do I delete the line in the file so it just prints:

Cat
Dog

using only the number they chose and not the actual words in the line?

Give us what you wrote – Bilel Korbosli May 08 '17 at 23:34 — Bilel Korbosli, May 08 '17 at 23:34

Dmitry Maslennikov · Accepted Answer · 2017-05-08T23:58:14.390

6

Use this:

$row_number = 0;    // Number of the line we are deleting
$file_out = file("file.txt"); // Read the whole file into an array

//Delete the recorded line
unset($file_out[$row_number]);

//Recorded in a file
file_put_contents("file.txt", implode("", $file_out));

edited May 08 '17 at 23:58

answered May 08 '17 at 23:44

Dmitry Maslennikov

338
2
8
22

loading the entire thing into memory isn't optimal for large files – Sam Dufel May 08 '17 at 23:47
Yes, it is true. But in the above question, as I understand, it's about a small amount of data. – Dmitry Maslennikov May 08 '17 at 23:49
This will print out the 2 desired lines from a new file? Because I'm trying to only use 1 file where the code actively removes the line from the file so only the two lines remain. – Cvm192 May 08 '17 at 23:56
Works great. Thanks a lot :-) – Cvm192 May 09 '17 at 00:08
How to do with a large amount of data, a big file ? – Loenix Jan 04 '21 at 16:23

PHP How to delete a specific line in a text file using user input?

1 Answers1