How can strpos() or stripos() functions be correctly utilized in PHP to search for specific substrings in a string from a CSV file?

To search for specific substrings in a string from a CSV file using strpos() or stripos() functions in PHP, you can read the CSV file line by line and then use strpos() or stripos() to search for the desired substring in each line. You can loop through each line of the CSV file, use strpos() or stripos() to check if the substring exists in the line, and perform any necessary actions based on the result.

<?php

// Open the CSV file for reading
$file = fopen('data.csv', 'r');

// Loop through each line of the CSV file
while (($line = fgetcsv($file)) !== false) {
    // Check if the desired substring exists in the line
    if (stripos($line[0], 'search_string') !== false) {
        // Perform actions if the substring is found
        echo 'Substring found in line: ' . implode(',', $line) . PHP_EOL;
    }
}

// Close the CSV file
fclose($file);

?>