Function proposal: nl2p

I wrote this very simple function (modification from nl2br actually) to
convert newlines to well formatted HTML paragraphs instead of line
breaks, allowing better formatting of a dynamic output. It's not the
most perfect piece of code ever written, but it works and it can be
quite useful.

The <br /> tag does not have as much possibilities as the <p> tag when
it comes to CSS, which gave me the idea to write this function.

--
Louis-Philippe Huberdeau

--- BEGIN ---

/* {{{ proto string nl2p(string str)
Converts newlines to HTML paragraphs for standard compliance /
PHP_FUNCTION(nl2p)
{
/ in brief this inserts </p>\n<p> before matched regexp \n\r?|\r\n? ,
<p> before the string and </p> after the string */
zval **zstr;
char *tmp, *str;
int new_length;
char *end, *target;
int repl_cnt = 0;
int seen_other_char = 0;

if (ZEND_NUM_ARGS() != 1 || zend_get_parameters_ex(1, &zstr) == FAILURE) {
	WRONG_PARAM_COUNT;
}

convert_to_string_ex(zstr);

str = Z_STRVAL_PP(zstr);
end = str + Z_STRLEN_PP(zstr);

/* it is really faster to scan twice and allocate mem once insted 

scanning once
and constantly reallocing */
while (str < end) {
if( seen_other_char ) {
if (str == '\r') {
if ((str+1) == '\n') {
str++;
}
repl_cnt++;

			seen_other_char = 0;
		} else if (*str == '\n') {
			if (*(str+1) == '\r') {
				str++;
			}
			repl_cnt++;

			seen_other_char = 0;
		}
	} else if( *str != '\n' && *str != '\r' ) {
		seen_other_char = 1;
	}
	
	str++;
}

if (repl_cnt == 0) {
	RETURN_STRINGL(Z_STRVAL_PP(zstr), Z_STRLEN_PP(zstr), 1);
}

new_length = Z_STRLEN_PP(zstr) + repl_cnt * (sizeof("\n</p>\n<p>") - 1) 

• sizeof("\n<p>\n") + sizeof("\n</p>");
  tmp = target = emalloc(new_length + 1);

  str = Z_STRVAL_PP(zstr);

  *target++ = '\n';
  *target++ = '<';
  *target++ = 'p';
  *target++ = '>';
  *target++ = '\n';

  seen_other_char = 0;

  while (str < end) {
  switch (*str) {
  case '\r':
  case '\n':
  if( seen_other_char ) {
  *target++ = '\n';
  *target++ = '<';
  *target++ = '/';
  *target++ = 'p';
  *target++ = '>';
  *target++ = '\n';
  *target++ = '<';
  *target++ = 'p';
  *target++ = '>';

    			if ((*str == '\r' && *(str+1) == '\n') || (*str == '\n' && *(str+1) 
  

== '\r')) {
*target++ = *str++;
}

				seen_other_char = 0;
			}

			*target++ = *str;
			break;
		default:
			seen_other_char = 1;
			*target++ = *str;
	}

	str++;
}

*target++ = '\n';
*target++ = '<';
*target++ = '/';
*target++ = 'p';
*target++ = '>';
*target++ = '\n';

*target = '\0';

RETURN_STRINGL(tmp, new_length, 0);

}
/* }}} */

--- END