Compare 2 text files and get internal id - php

Question

I tried comparing 2 text files with data separated by -, in one case one file gets all data and in another case only has the data for change with the same id in this case this file it's called db_tmp.txt
The structure in both files it's this :
File txt ( the first it´s the id ) db/text.txt
1a34-Mark Jhonson
1a56-Jhon Smith
1a78-Mary Walter
The file for comparing, has for example the data for change, same id but different content - db_tmp.txt
1a56-Tom Tom
I created a function for comparing both files to detect if the same id and change exists:
<?php
$cron_file = file("db_tmp.txt");
$cron_compare = file("db/test.txt");
function cron($file_temp, $file_target)
{
for ($fte = 0; $fte < sizeof($file_temp); $fte++) {
$exp_id_tmp = explode("-", $file_temp[$fte]);
$cr_temp[] = "" . $exp_id_tmp[0] . "";
}
for ($ftt = 0; $ftt < sizeof($file_target); $ftt++) {
$exp_id_targ = explode("-", $file_target[$ftt]);
$cr_target[] = "" . $exp_id_targ[0] . "";
}
$diff = array_diff($cr_target, $cr_temp);
$it = 0;
foreach ($diff as $diff2 => $key) {
echo $diff2;
echo "--- $key";
print "<br>";
}
}
cron($cron_file, $cron_compare);
?>
If the same id exists in tmp, i must detect the entry in the other file and change to the value of the tmp, i try but can't get this to work, the function works but not for everything, if anyone can help me, that would be perfect, because i don´t know how continue this and save.

Answer 1

If you want to match according to id, a simple foreach would suffice, then just check during the loop if they have the same key. Consider this example:
// sample data from file('db_text.txt');
$contents_from_text = array('1a34-Mark Jhonson','1a56-Jhon Smith', '1a87-Mary Walter');
// reformat
$text = array();
foreach($contents_from_text as $element) {
list($key, $value) = explode('-', $element);
$text[$key] = $value;
}
$tmp = array();
// sample data from file('db_tmp.txt');
$contents_from_tmp = array('1a56-Tom Tom', '1a32-Magic Johnson', '1a23-Michael Jordan', '1a34-Larry Bird');
foreach($contents_from_tmp as $element) {
list($key, $value) = explode('-', $element);
$tmp[$key] = $value;
}
// compare
foreach($tmp as $key => $value) {
foreach($text as $index => $element) {
if($key == $index) {
$tmp[$key] = $element;
}
}
}
$contents_from_tmp = $tmp;
print_r($contents_from_tmp);
Sample Output