mb_str_pad

gistfile1.txt

// This function need the mb_string;
// This function is based on the native str_pad from PHP (https://github.com/php/php-src/blob/master/ext/standard/string.c#L5332);

const STR_PAD_INSERT_ALL = 4;

function mb_str_pad(string $input, int $pad_length, string $pad_string, int $pad_type, string $pad_encoding = 'utf8') : string {

    $result = '';
    $pad_insert_all = 0;
    $pad_inset_limit = 1;
    $pad_str_len = mb_strlen($pad_string, $pad_encoding);
    $input_len = mb_strlen($input, $pad_encoding);

    if ($pad_length < 0 || $pad_length <= $input_len) {
        return $input;
    }

    if(($pad_type & STR_PAD_INSERT_ALL) === STR_PAD_INSERT_ALL){
        $pad_insert_all = PHP_INT_MAX;
        $pad_inset_limit = null;
        $pad_type -= STR_PAD_INSERT_ALL;
    }

    if ($pad_str_len === 0) {
        trigger_error ( "Padding string cannot be empty", E_WARNING);
        return $input;
    }

    if ($pad_type < STR_PAD_LEFT || $pad_type > STR_PAD_BOTH) {
        trigger_error ("Padding type has to be STR_PAD_LEFT, STR_PAD_RIGHT, or STR_PAD_BOTH", E_WARNING);
        return $input;
    }

    $num_pad_chars = $pad_length - $input_len;
    if ($num_pad_chars >= PHP_INT_MAX) {
        trigger_error ("Padding length is too long", E_WARNING);
        return $input;
    }

    switch ($pad_type) {
        case STR_PAD_RIGHT:
            $left_pad = 0;
            $right_pad = $num_pad_chars;
            break;

        case STR_PAD_LEFT:
            $left_pad = $num_pad_chars;
            $right_pad = 0;
            break;

        case STR_PAD_BOTH:
            $left_pad = floor($num_pad_chars / 2);
            $right_pad = $num_pad_chars - $left_pad;
            break;
    }

    for ($i = 0; $i < $left_pad; $i++){
        $result .= mb_substr($pad_string, ($i % $pad_str_len) &~$pad_insert_all, $pad_inset_limit, $pad_encoding);
    }

    $result .= $input;

    for ($i = 0; $i < $right_pad; $i++){
        $result .= mb_substr($pad_string, ($i % $pad_str_len) &~$pad_insert_all, $pad_inset_limit, $pad_encoding);
    }

    return $result;
}

gistfile2.txt

# Native str_pad:

$result = str_pad('漢字', 19, 'ç', STR_PAD_BOTH); 
//= ççç漢字ççç�



# Custom mb_str_pad with multi-byte input and single multi-byte character pad:

$result = mb_str_pad('漢字', 19, 'ç', STR_PAD_BOTH, 'utf8');
//= çççççççç漢字ççççççççç

$result = mb_str_pad('漢字', 20, 'ç', STR_PAD_LEFT, 'utf8');
//= ççççççççççççççççç漢字

$result = mb_str_pad('漢字', 20, 'ç', STR_PAD_RIGHT, 'utf8');
//= 漢字çççççççççççççççççç



# Custom mb_str_pad with multi-byte input and multiples multi-bytes characters pad:

$result = mb_str_pad('漢字', 19, '$¬¬', STR_PAD_BOTH, 'utf8');
//= $¬¬$¬¬$¬漢字$¬¬$¬¬$¬¬

$result = mb_str_pad('漢字', 19, '$¬¬', STR_PAD_BOTH | STR_PAD_INSERT_ALL, 'utf8');
//= $¬¬$¬¬$¬¬$¬¬$¬¬$¬¬$¬¬$¬¬漢字$¬¬$¬¬$¬¬$¬¬$¬¬$¬¬$¬¬$¬¬$¬¬