From a5a9c91cb6f18159e39c87143ece06a4ceb8d7df Mon Sep 17 00:00:00 2001
From: emma <emma@tebibyte.media>
Date: Tue, 4 Jun 2024 14:28:19 -0600
Subject: [PATCH] getopt.rs(3): optind support

---
 src/getopt.rs | 49 ++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 36 insertions(+), 13 deletions(-)

diff --git a/src/getopt.rs b/src/getopt.rs
index b146400..79879df 100644
--- a/src/getopt.rs
+++ b/src/getopt.rs
@@ -18,6 +18,21 @@
 
 use std::ffi::{ c_int, c_char, CString, CStr };
 
+
+/* binding to getopt(3p) */
+extern "C" {
+	static mut optarg: *mut c_char;
+	static mut _opterr: c_int;
+	static mut optind: c_int;
+	static mut optopt: c_int;
+
+	fn getopt(
+		___argc: c_int,
+		___argv: *const *mut c_char,
+		__shortopts: *const c_char,
+	) -> c_int;
+}
+
 pub struct Opt {
 	pub arg: Option<String>,
 	pub ind: i32,
@@ -50,7 +65,7 @@ impl GetOpt for Vec<String> {
         let opts = CString::new(optstring).unwrap().into_raw();
         let len = self.len() as c_int;
 
-        unsafe { // TODO: enable optind modification
+        unsafe {
             match getopt(len, argv_ptr, opts) { 
 				/* From getopt(3p):
 				 *
@@ -103,16 +118,24 @@ impl GetOpt for Vec<String> {
         }
     }
 }
-/* binding to getopt(3p) */
-extern "C" {
-	static mut optarg: *mut c_char;
-	static mut _opterr: c_int;
-	static mut optind: c_int;
-	static mut optopt: c_int;
 
-	fn getopt(
-		___argc: c_int,
-		___argv: *const *mut c_char,
-		__shortopts: *const c_char,
-	) -> c_int;
-}
+/* From getopt(3p):
+ *
+ * The variable optind is the index of the next element of the argv[]
+ * vector to be processed. It shall be initialized to 1 by the system, and
+ * getopt() shall update it when it finishes with each element of argv[].
+ * If the application sets optind to zero before calling getopt(), the 
+ * behavior is unspecified. When an element of argv[] contains multiple
+ * option characters, it is unspecified how getopt() determines which
+ * options have already been processed.
+ *
+ * This API can be utilized using unsafe blocks and dereferencing:
+ *
+ * use getopt::OPTIND;
+ *
+ * unsafe { while *OPTIND < 5 {
+ *	println!("{}", *OPTIND); // 1..4
+ *	*OPTIND += 1;
+ * }}
+ */
+pub static mut OPTIND: *mut i32 = unsafe { std::ptr::addr_of_mut!(optind) };