This function returns a copy of the string represented by string with embedded backslash (\), quote ("), and dollar sign ($) characters escaped with \ to form a valid ACL string operand. Each literal new line character in the string is replaced with the sequence \n. The resulting string is delimited with double quotes. For example, quote('String with \ and $ embedded') would return "String with \\ and \$ embedded".

If the flags parameter is 0x01 then dollar signs are not escaped, allowing variable substitution to be performed on the resulting string.