unikernel/duniverse/mirage-bootvar/parse_argv/mirage_bootvar_parse_argv.ml

@@ -0,0 +1,47 @@
+(*
+ * Copyright (c) mirage-bootvar AUTHORS
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ *)
+
+(* Split string into whitespace-separated substrings,
+   taking into account quoting *)
+
+type state = Quoted_escaped | Quoted | Escaped | Normal
+
+let chars_to_str = function
+  | [] -> []
+  | chars ->
+      let chars = List.rev chars in
+      [ String.init (List.length chars) (List.nth chars) ]
+
+let parse s =
+  let l = String.length s in
+  let rec loop acc curr state idx =
+    if idx = l then
+      if state = Normal then Ok (List.rev (chars_to_str curr @ acc))
+      else Error "bad input line - either escaped or quoted or both"
+    else
+      match (state, String.unsafe_get s idx) with
+      | Normal, ' ' -> loop (chars_to_str curr @ acc) [] state (idx + 1)
+      | Escaped, c -> loop acc (c :: curr) Normal (idx + 1)
+      | Quoted_escaped, c -> loop acc (c :: curr) Quoted (idx + 1)
+      | Quoted, '\\' -> loop acc curr Quoted_escaped (idx + 1)
+      | Quoted, '"' -> loop acc curr Normal (idx + 1)
+      | Quoted, c -> loop acc (c :: curr) Quoted (idx + 1)
+      | Normal, '\\' -> loop acc curr Escaped (idx + 1)
+      | Normal, '"' -> loop acc curr Quoted (idx + 1)
+      | Normal, c -> loop acc (c :: curr) Normal (idx + 1)
+  in
+  loop [] [] Normal 0