Function patternToSQLRegex

src/fe_utils/string_utils.c:1180–1346

* Transform a possibly qualified shell-style object name pattern into up to * three SQL-style regular expressions, converting quotes, lower-casing * unquoted letters, and adjusting shell-style wildcard characters into regexp * notation. * * If the dbnamebuf and schemabuf arguments are non-NULL, and the pattern * contains two or more dbname/schema/name separators, we parse the portions of *

 * pattern.
 */
void
patternToSQLRegex(int encoding, PQExpBuffer dbnamebuf, PQExpBuffer schemabuf,
				  PQExpBuffer namebuf, const char *pattern, bool force_escape,
				  bool want_literal_dbname, int *dotcnt)
{
	PQExpBufferData buf[3];
	PQExpBufferData left_literal;
	PQExpBuffer curbuf;
	PQExpBuffer maxbuf;
	int			i;
	bool		inquotes;
	bool		left;
	const char *cp;

	Assert(pattern != NULL);
	Assert(namebuf != NULL);

	/* callers should never expect "dbname.relname" format */
	Assert(dbnamebuf == NULL || schemabuf != NULL);
	Assert(dotcnt != NULL);

	*dotcnt = 0;
	inquotes = false;
	cp = pattern;

	if (dbnamebuf != NULL)
		maxbuf = &buf[2];
	else if (schemabuf != NULL)
		maxbuf = &buf[1];
	else
		maxbuf = &buf[0];

	curbuf = &buf[0];
	if (want_literal_dbname)
	{
		left = true;
		initPQExpBuffer(&left_literal);
	}
	else
		left = false;
	initPQExpBuffer(curbuf);
	appendPQExpBufferStr(curbuf, "^(");
	while (*cp)
	{
		char		ch = *cp;

		if (ch == '"')
		{
			if (inquotes && cp[1] == '"')
			{
				/* emit one quote, stay in inquotes mode */
				appendPQExpBufferChar(curbuf, '"');
				if (left)
					appendPQExpBufferChar(&left_literal, '"');
				cp++;
			}
			else
				inquotes = !inquotes;