Variable does not want to work

[davidx714]

Hello everyone. I am trying to learn PHP and I am stuck.

 

I have a text file that has the numbers 1 through 9, each listed on its own line. I want to read each line of the file, and write it to a new text file UNLESS one of the numbers is passed through the URL.

 

So for example, if the url variable is 8, then it will read the first file and write

1

2

3

4

5

6

7

9

To the second file.

 

Here is what I got:

 

 

<?php

 

$linknum = $_GET['linknum'];

 

 

//----This works if $xx = 8;

//$xx = 8;

 

//----but it does not work if $xx = $linknum;

$xx = $linknum;

 

$data = file ("Source_file.txt");

$b = fopen("New_File.txt", "w+");

foreach ($data as $zz) {

if ($zz != $xx){

fwrite($b, $zz);

}

}

 

?>

 

 

Please help me!

[Pikachu2000]

It would be helpful to see the form you're using to submit the data to this script.

[Pikachu2000]

On second look, nevermind. I see you're simply passing the value in the URL. I just changed it a little to read the values from an an array, and then echo the result instead of writing a file and tested it locally, and it seems to work just fine.

[davidx714]

Forgive my ignorance ... I just started learning ... can you show me what you did to get it to work?

[oni-kun]

$b = fopen("New_File.txt", "w+"); 

 

w+ will clear the entire file and its contents, and place the pointer at the beginning of the file. Do you mean "w"?

[davidx714]

I just tried "w" and the same thing happens:

 

It works if $xx = 8; but it does not work if $xx = $linknum;

 

[anupamsaha]

Please try using "rb+" instead of "w".

 

Hope this will help.

 

Thanks.

[frankienrg]

well well, i thinks it's the way you pass the variable that doesn't work:

 

the url should be: http://www.somedomain.com/index.php?linknum=8

[Pikachu2000]

I just figured out what is going on here. If you typecast the $xx variable as an integer when you assign its value from $linknum, it works just fine. I also made the code a little more compact by eliminating redundancy in assigning values to variables.

<?php
$xx = (int) $_GET['linknum']; // typecast as an integer here, now the != comparison works when value is passed via URL.
$data = file ("Source_file.txt");
$b = fopen("New_File.txt", "w+");
foreach ($data as $zz) {
if ($zz != $xx){
	fwrite($b, $zz);
}
}
?>

[davidx714]

Pikachu2000! YES! That did it. Thank you very much!!!

[Pikachu2000]

No problem at all . . .