Combining two text files with PHP - ForEach loops - php

Question

I'm completely puzzled where to even start on this, but I need to provide a list of keywords in file A and then the same in list B.
With these too files I want to append the lines in A foreach line in file B
For example:
File A:
line1
line2
line3
File B:
test1
test2
test3
Output to a combined.txt file:
line1test1
line2test1
line3test1
line1test2 ... and so on
If you could provide me the portions of the script to research, a sample script, or even a working way to do it. I would greatly appreciate it.
Per request, here is my sample code:
<?php
$file1 = 'keywords.txt';
$file2 = 'topics.txt';
$combined = 'combined.txt';
$keywords = fopen("keywords.txt", "rb");
$topics = fopen("topics.txt", "rb");
$front = explode($topics);
$back = explode($topics);
while (!feof($keywords) ) {
file_put_contents($combined, . $front ."". $back . "\n");
fclose($keywords & $topics);
}
?>

Answer 1

Hope this helps. Comments are sprinkled throughout the code, which I hope is sufficient explanation as to what I'm doing.
<?php
// Open keywords file for reading
$keywords_file = 'keywords.txt';
$keywords_fh = fopen($keywords_file, 'r');
// Get line by line from keywords file, push into $keywords array
// Make sure to trim each line from fgets, to strip off \n at end.
$keywords = array();
while ($line = trim(fgets($keywords_fh))) {
array_push($keywords, $line);
}
fclose($keywords_fh);
// Open topics file for reading
$topics_file = 'topics.txt';
$topics_fh = fopen($topics_file, 'r');
// Get line by line from topics file, push into $topics array
// Make sure to trim each line from fgets, to strip off \n at end.
$topics = array();
while ($line = trim(fgets($topics_fh))) {
array_push($topics, $line);
}
fclose($topics_fh);
// Open combined file for writing
$combined_file = 'combined.txt';
$combined_fh = fopen($combined_file, 'w');
// Iterate through each keyword.
// For each iteration, iterate through each topic.
// Write the concatenation of keyword and topic to file.
foreach ($keywords as $keyword) {
foreach ($topics as $topic) {
fwrite($combined_fh, "$keyword$topic\n");
}
}
fclose($combined_fh);
Here are some links to PHP documentation for some of the key functions I used:
fopen
trim
fgets
fwrite
fclose

Answer 2

$f1 = explode("\n",file_get_contents("fileA.txt"));
$f2 = explode("\n",file_get_contents("fileB.txt"));
foreach ($f1 as $key => $value) {
$f3[] = $value.$f2[$key];
}
file_put_contents("fileC.txt", implode("\n",$f3));