MySQL PHP: PDO connection not working when getting credentials from file() - php

Question

I've already searched for an answer to this questions, but all that I found didn't work for me. I've a problem with the pdo connection in php.
When I enter the mysql datas directly into the pdo statement, it works properly. But when I use variables instead, it doesn't. I already looked up how to include variables into a pdo statement, but it didn't work.
This is the code, when it works:
$host = 'localhost';
$username = 'root';
$password = 'password';
$dbname = 'Database';
$con = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
And here is the code, when it doesn't work:
$file = "mysqldatas.txt";
$lines = file($file);
$host = $lines[1];
$username = $lines[2];
$password = $lines[3];
$dbname = $lines[4];
$con = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
As you can see, I try to read the datas from a text file the second time. But I don't see where the difference between 'localhost', and $lines[1] is, because when I echo the $lines[1], the output is localhost, as it should be.
Please help me guys, this is really annoying. It would be great, if you could also explain why it makes a difference between directly entering the hostname, or using a variable, that holds the hostname (as I said, I used echo, and it said localhost).
Thank you for your help guys!
Bye.

Answer 1

The actual issue is that the file() will also get newlines with each line, unless the FILE_IGNORE_NEW_LINES is used (or some sort of trim() function). So you'll need to use
$lines = file($file, FILE_IGNORE_NEW_LINES);
instead. From the manual of file(), it tells us that
Note:
Each line in the resulting array will include the line ending, unless FILE_IGNORE_NEW_LINES is used, so you still need to use rtrim() if you do not want the line ending present.
trim() is also a possibility instead of this flag.
There's a few other, different possibilities to separate credentials and connections, the most common one is to either use a file connection.php which creates the object, where you just include that, and use that wherever you need a connection, or creating your own .ini file with the credentials, and getting it via parse_ini_file().
connection.php
$host = 'localhost';
$username = 'root';
$password = 'password';
$dbname = 'Database';
$con = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
Other files
require "path/to/connection.php";
$con->prepare(...);
Then there's usage of .ini files. You can create a config.ini file, and get the values from parse_ini_file()
config.ini
host = localhost
dbname = Database
user = root
password = password
type = mysql
Connection
$config = parse_ini_file("config.ini");
$con = new PDO($config['type'].":host=".$config['host'].";dbname=".$config['dbname'], $config['username'], $config['password']);
References
http://php.net/manual/en/function.file.php
http://php.net/manual/en/function.trim.php or http://php.net/manual/en/function.rtrim.php
http://php.net/manual/en/function.parse-ini-file.php

Answer 2

pretty sure you are getting newlines when you use the file function. try this:
$file = "mysqldatas.txt";
$lines = file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$host = $lines[1];
$username = $lines[2];
$password = $lines[3];
$dbname = $lines[4];
$con = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);

Answer 3

From http://php.net/manual/en/function.file.php :
Return Values ¶
Returns the file in an array. Each element of the array corresponds to a line in the file, with the newline still attached. Upon failure, file() returns FALSE.