Converts an UTF-8 string into the best possible representation
as a STRING. The representation of characters not in STRING
is not specified; it may be as pseudo-escape sequences
\x{ABCD}, or it may be in some other form of approximation.
the newly-allocated string, or NULL if the
conversion failed. (It should not fail for any properly
formed UTF-8 string unless system limits like memory or
file descriptors are exceeded.)
Converts an UTF-8 string into the best possible representation as a STRING. The representation of characters not in STRING is not specified; it may be as pseudo-escape sequences \x{ABCD}, or it may be in some other form of approximation.