posix: add package

core/sys/posix/sys_utsname.odin

@@ -0,0 +1,55 @@
+package posix
+
+import "core:c"
+
+when ODIN_OS == .Darwin {
+	foreign import lib "system:System.framework"
+} else {
+	foreign import lib "system:c"
+}
+
+// sys/utsname.h = system name structure
+
+foreign lib {
+	/*
+	Stores information identifying the current system in the given structure.
+
+	Returns: non-negative on success, -1 (setting errno) on failure
+
+	NOTE: have a look at `core:sys/info` for similar/better system information.
+	
+	Example:
+		uname: posix.utsname
+		posix.uname(&uname)
+		fmt.printfln("%#v", uname)
+
+	Possible Output:
+		utsname{
+			sysname = Darwin,
+			nodename = Laytans-MacBook-Pro.local,
+			release = 23.5.0,
+			version = Darwin Kernel Version 23.5.0: Wed May  1 20:16:51 PDT 2024; root:xnu-11331.111.3~1/RELEASE_ARM64_T8103,
+			machine = arm64,
+		}
+
+	[[ More; https://pubs.opengroup.org/onlinepubs/9699919799/functions/uname.html ]]
+	*/
+	uname :: proc(uname: ^utsname) -> c.int ---
+}
+
+when ODIN_OS == .Darwin || ODIN_OS == .FreeBSD || ODIN_OS == .NetBSD || ODIN_OS == .OpenBSD {
+
+	@(private)
+	_SYS_NAMELEN :: 256
+
+	utsname :: struct {
+		sysname:  [_SYS_NAMELEN]c.char `fmt:"s,0"`, /* [PSX] name of OS */
+		nodename: [_SYS_NAMELEN]c.char `fmt:"s,0"`, /* [PSX] name of this network node */
+		release:  [_SYS_NAMELEN]c.char `fmt:"s,0"`, /* [PSX] release level */
+		version:  [_SYS_NAMELEN]c.char `fmt:"s,0"`, /* [PSX] version level */
+		machine:  [_SYS_NAMELEN]c.char `fmt:"s,0"`, /* [PSX] hardware type */
+	}
+
+} else {
+	#panic("posix is unimplemented for the current target")
+}