Counts the number of lines in a container where character count per line is known or approximate.

line_count.php

<?php

/**
 * Counts the number of lines in a container where character count per line is known or approximate.
 * It assumes that words can be broken.
 *
 * @param string $text
 * @param int    $perLine
 *
 * @return int
 */
function lineCount($text, $perLine = 90)
{
    $lines = 0;
    $prev  = 0;
    $next  = 0;
    while (isset($text[$next]) && false !== ($next = strpos($text, "\n", $next))) {
        $lines += (int)ceil(($next - $prev) / $perLine);
        $prev = ++$next;
    }

    $l = strlen($text);
    if ($prev < $l - 1) {
        $lines += (int)ceil(($l - 1 - $prev) / $perLine);
    }

    return $lines;
}