Converts all upper case ASCII letters to lower case ASCII letters.
a string
length of str in bytes, or -1 if str is nul-terminated
a newly-allocated string, with all the upper case characters in str converted to lower case, with semantics that exactly match g_ascii_tolower(). (Note that this is unlike the old g_strdown(), which modified the string in place.)
Converts all upper case ASCII letters to lower case ASCII letters.