How to read a file line by line in PHP - php

Question

I have an archive txt in this format.
$line[0] = 50009828720001007029552330034 20181009MG551 0119195102P000000002624400000000000000000000000000000000000000000000000262440000N
In this line I can get many information of a determinated document.
Example: When I use the functions below I can get the number of document, date of document, and another information.
$numDoc[0] = (string)substr($line[0], 46, 5); // THE NUMBER OF DOCUMENT IS 011919
$dateDoc[0] = (string)substr($line[0], 30, 8); // DATE OF DOCUMENT IS 20181009
How I can structure my archive to easy print the information ordered like this.
NUMBER OF DOCUMENT - DATE DOCUMENT
What the easy way to ordered this information, is a small application does not allow user make anything, just upload this archive .txt.
My question is about structure the informations for easy acess, like bellow:
doc1{
number = xxx
date = xxx
generic = xxx
}

Answer 1

I assume you need a way to make it more dynamic than manually typing [0] then [1] and so on?
You can loop the txtfile with foreach and assign new array items with [].
$file = fopen("path of txt");
foreach($file as $line){
$numDoc[] = substr($line, 46, 5);
$dateDoc[] = substr($line, 30, 8);
}
The code above will loop through the document and create two arrays with the dates and the document number.
I would probably make it an multidimensional array instead to keep all in one place.
foreach($file as $line){
$array["numdoc"][] = substr($line, 46, 5);
$array["dateDoc"][] = substr($line, 30, 8);
}