PHP get file line by line and compare to string

Question

I have a file which is basically a list of names in that format:

name.lastname
name.lastname
name.lastname
myname.mylastname
name.lastname

and I want to check whether a string I have is equal to one of the names (with the dot).

Thats what I tried already:


$username = "myname.mylastname"; 
$boolean = False; 
$handle = fopen("thelist.txt","r");
while (($line = fgets($handle)) !== false) {
        if ($line === $username){
            $liste = True; 
        }
    }

after that list keeps being False and I dont know why.

Thanks in advance :)

I'd check if $line is returned as a string because you are using === try == and see if that returns true. — Dylan Anlezark, Nov 24 '19 at 21:36
@DylanAnlezark I still get false unfortunatly. But what i found was that when i echo each $line, that there are spaces in between them although i wouldnt imagine that there should be spaces — BestDravenHildesheim, Nov 24 '19 at 21:40
Are you able to print out just before your if statement what `$line` is and what `$username` is and share that with us? — Dylan Anlezark, Nov 24 '19 at 21:41
@DylanAnlezark for the first part of the loop i get "alexander.schmidt omar.remmo" and then later i get "nina.wietbrock omar.remmoomar.remmo omar.remmoozan.dincer omar.remmo" — BestDravenHildesheim, Nov 24 '19 at 21:44
Sorry I don't quite understand so does "alexander.schmidt omar.remmo" = `$username`? And the other names = `$line` — Dylan Anlezark, Nov 24 '19 at 21:47
@DylanAnlezark "alexander.schmidt" is the $line and "omar.remmo" is $username. "echo $line; echo $username;" is what i wrote in my code in the loop — BestDravenHildesheim, Nov 24 '19 at 21:49
@DylanAnlezark The first one is what prints after the first go through of the loop and later is where $username and $line should be identical — BestDravenHildesheim, Nov 24 '19 at 21:51
What happens if instead of `if ($line === $username){` you hardcode the expected value of `if ("omar.remmo"=== $username){` do you then enter your if statement? — Dylan Anlezark, Nov 24 '19 at 22:04
I still thinking that it has to do with the type of the data you are getting back from `fgets($handle)` What happens if you use `if ($line.toString() === $username){` — Dylan Anlezark, Nov 24 '19 at 22:09
@DylanAnlezark then it crashes when it gets there. I dont get an error tho so i dont really know whats wrong — BestDravenHildesheim, Nov 24 '19 at 22:13
Can you add a screenshot of your echos that you are getting? — Dylan Anlezark, Nov 24 '19 at 22:23
At least you can `trim()` whitespaces or check if each char is allowed, ie in range `a-zA-Z` while accepting the dot as valid one — 1000Gbps, Nov 24 '19 at 22:27

Will B. · Accepted Answer · 2019-11-25T01:04:52.777

There are a few potential issues I see.

First $boolean = False; while $liste = True;, so you may have a potential typo in your output variable.

Second issue is that thelist.txt is not an absolute path. So the file resource may have failed to be loaded. It is highly recommended that you use an absolute path to file resources such as /full/path/to/file or __DIR__ . '/path/to/file'.

The main issue is that fgets will include the \r and \n at the end of each line in the file, that does not exist in the compared string variable. You can use trim to remove extraneous line endings and white spaces to compare with the string variable.

Example: https://3v4l.org/4VG4D

$username = "myname.mylastname"; 
$liste = false; 

$handle = fopen("thelist.txt", 'rb');
while (false !== ($line = fgets($handle))) {
    if (trim($line) === $username){
        $liste = true;
        break; //stop at first match
    }
}
fclose($handle);
var_dump($liste); //true

PHP get file line by line and compare to string

1 Answers1

Example: https://3v4l.org/4VG4D