posix: add package

core/sys/posix/iconv.odin

@@ -0,0 +1,50 @@
+package posix
+
+import "core:c"
+
+when ODIN_OS == .Darwin {
+	// NOTE: iconv is in a different library
+	foreign import lib "system:iconv"
+} else {
+	foreign import lib "system:c"
+}
+
+// iconv.h - codeset conversion facility
+
+iconv_t :: distinct rawptr
+
+foreign lib {
+	/*
+	Convert the sequence of characters from one codeset, in the array specified by inbuf,
+	into a sequence of corresponding characters in another codeset, in the array specified by outbuf.
+
+	Returns: -1 (setting errno) on failure, the number of non-identical conversions performed on success
+
+	[[ More; https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv.html ]]
+	*/
+	iconv :: proc(
+		cd:          iconv_t,
+		inbuf:       ^[^]byte,
+		inbytesleft: ^c.size_t,
+		outbuf:      ^[^]byte,
+		outbyteslen: ^c.size_t,
+	) -> c.size_t ---
+
+	/*
+	Deallocates the conversion descriptor cd and all other associated resources allocated by iconv_open().
+
+	[[ More; https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv_close.html ]]
+	*/
+	iconv_close :: proc(cd: iconv_t) -> result ---
+
+	/*
+	Returns a conversion descriptor that describes a conversion from the codeset specified by the
+	string pointed to by the fromcode argument to the codeset specified by the string pointed to by
+	the tocode argument.
+
+	Returns: -1 (setting errno) on failure, a conversion descriptor on success
+
+	[[ More; https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv_open.html ]]
+	*/
+	iconv_open :: proc(tocode: cstring, fromcode: cstring) -> iconv_t ---
+}