From 7894831e9078211df0b460c4d3dd1bc51ca46804 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 17 May 2018 10:45:49 +0100
Subject: [PATCH] admin.scala: Start on understanding the administration
 protocol.

---
 Makefile    |  2 ++
 admin.scala | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)
 create mode 100644 admin.scala

diff --git a/Makefile b/Makefile
index 873380a..cd8e4a4 100644
--- a/Makefile
+++ b/Makefile
@@ -53,6 +53,8 @@ TARGETS			+= jni.stamp
 TARGETS			+= sock.stamp
 sock.stamp: jni.stamp
 
+TARGETS			+= admin.stamp
+
 TARGETS			+= main.stamp
 main.stamp: jni.stamp sock.stamp
 
diff --git a/admin.scala b/admin.scala
new file mode 100644
index 0000000..85978fe
--- /dev/null
+++ b/admin.scala
@@ -0,0 +1,72 @@
+package uk.org.distorted.tripe;
+
+import scala.collection.mutable.ArrayBuffer;
+
+object Admin {
+  val RX_ORDINARY = "^[^\\\\'\"\\s]+$".r;
+  val RX_WEIRD = "[\\\\'\"]".r;
+
+  def quote(v: Seq[String]) = {
+    val b = new StringBuilder;
+    var sep = false;
+    for (s <- v) {
+      if (!sep) sep = true;
+      else b.append(' ');
+      s match {
+	case RX_ORDINARY() => b.append(s);
+	case _ =>
+	  b.append('"');
+	  b.append(RX_WEIRD.replaceAllIn(s, "\\\\$0"));
+	  b.append('"');
+      }
+    }
+    b.mkString
+  }
+
+  class InvalidQuotingException(msg: String) extends Exception(msg);
+
+  def split(s: String): Array[String] = {
+    val ab = new ArrayBuffer[String]();
+    val sb = new StringBuilder;
+
+    object State extends Enumeration {
+      val BETWEEN, WORD, SQUOTE, DQUOTE = Value;
+    }
+    import State.{Value => _, _};
+
+    val n = s.length;
+
+    def scan(pos: Int, st: State.Value, bs: Boolean)
+    {
+      if (pos >= n) {
+	if (bs)
+	  throw new InvalidQuotingException("trailing `\\'");
+	else if (st == SQUOTE || st == DQUOTE)
+	  throw new InvalidQuotingException("unmatched quote");
+	if (st != BETWEEN) ab += sb.mkString;
+      } else (st, bs, s(pos)) match {
+	case (BETWEEN, false, '\\') => scan(pos + 1, WORD, true);
+	case (_, false, '\\') => scan(pos + 1, st, true);
+	case (SQUOTE, false, ''') | (DQUOTE, false, '"') =>
+	  scan(pos + 1, WORD, false);
+	case (BETWEEN | WORD, false, ''') => scan(pos + 1, SQUOTE, false);
+	case (BETWEEN | WORD, false, '"') => scan(pos + 1, DQUOTE, false);
+	case (BETWEEN, false, ch) if ch.isWhitespace =>
+	  scan(pos + 1, st, false);
+	case (WORD, false, ch) if ch.isWhitespace =>
+	  ab += sb.mkString; sb.clear();
+	  scan(pos + 1, BETWEEN, false);
+	case (BETWEEN, _, ch) => sb.append(ch); scan(pos + 1, WORD, false);
+	case (_, _, ch) => sb.append(ch); scan(pos + 1, st, false);
+      }
+    }
+    scan(0, BETWEEN, false);
+    ab.toArray
+  }
+
+  def main(args: Array[String])
+  {
+    if (args.length != 1) println(quote(args));
+    else for (s <- split(args(0))) println(s);
+  }
+}
-- 
2.11.0