php function fgets() unexpectet result - php

Question

#!/usr/bin/php
<?php
define("KPA_PEOPLE","/devel/pic/snk_db2/KPA-migration/Keywords/gettingTheKeywordsAndFiles/KPA_People.txt");
$hndl_kpa_people=fopen(KPA_PEOPLE,"r+") or die("Failed opening ".KPA_PEOPLE);
while($line=fgets($hndl_kpa_people)!==FALSE){
echo "\nline: ".$line."\n";
}
?>
Context:
The file looks like this in the file system:
-rw-r--r-- 1 snkdb snkdb 6096 dec 25 14:08 KPA_People.txt
(I'm the user snkdb)
The file's contents looks like:
et|2
Elisabet|3
okända|4...
The result looks like:
line: 1
line: 1
line: 1...
the expected result was:
et|2
Elisabet|3
okända|4...
as far as I understand the "while($line=fgets($hndl_kpa_people)!==FALSE)"
follows the convention in the manual and looks like it works in earlier scripts.
Any thoughts would be appreciated!

Answer 1

In the following line:
while($line=fgets($hndl_kpa_people)!==FALSE)
PHP is first evaluating the expression fgets($hndl_kpa_people)!==FALSE and then assigns it to the variable $line.
Furthermore, it is redundant to evaluate if something inside the while loop is different from false, since while loop runs while the condition it's evaluating is true.
So the line should be:
while($line = fgets($hndl_kpa_people))
You can read more on Operator Precedence in the official documentation: https://www.php.net/manual/en/language.operators.precedence.php
You can read more about while loop here: https://www.php.net/manual/en/control-structures.while.php
Edit: Since there is a confusion in the comments whether reading an empty line will return false - it will not. Take the following simple example:
<?php
$file = fopen('sample.txt', "r+");
$counter = 0;
while ($line = fgets($file)) {
print_r("Counter: $counter - Line: " . $line);
$counter++;
}
fclose($file);
with the following sample file:
test 123
test 234
test 345
The result from execution is:
Counter: 0 - Line: test 123
Counter: 1 - Line:
Counter: 2 - Line: test 234
Counter: 3 - Line: test 345