--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/argmatch.c	Sat Oct 31 20:42:48 1992 +0000
@@ -0,0 +1,83 @@
+/* argmatch.c -- find a match for a string in an array
+   Copyright (C) 1990 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Written by David MacKenzie <djm@ai.mit.edu> */
+
+#include <stdio.h>
+#ifdef STDC_HEADERS
+#include <string.h>
+#endif
+
+extern char *program_name;
+
+/* If ARG is an unambiguous match for an element of the
+   null-terminated array OPTLIST, return the index in OPTLIST
+   of the matched element, else -1 if it does not match any element
+   or -2 if it is ambiguous (is a prefix of more than one element).  */
+
+int
+argmatch (arg, optlist)
+     char *arg;
+     char **optlist;
+{
+  int i;			/* Temporary index in OPTLIST.  */
+  int arglen;			/* Length of ARG.  */
+  int matchind = -1;		/* Index of first nonexact match.  */
+  int ambiguous = 0;		/* If nonzero, multiple nonexact match(es).  */
+  
+  arglen = strlen (arg);
+  
+  /* Test all elements for either exact match or abbreviated matches.  */
+  for (i = 0; optlist[i]; i++)
+    {
+      if (!strncmp (optlist[i], arg, arglen))
+	{
+	  if (strlen (optlist[i]) == arglen)
+	    /* Exact match found.  */
+	    return i;
+	  else if (matchind == -1)
+	    /* First nonexact match found.  */
+	    matchind = i;
+	  else
+	    /* Second nonexact match found.  */
+	    ambiguous = 1;
+	}
+    }
+  if (ambiguous)
+    return -2;
+  else
+    return matchind;
+}
+
+/* Error reporting for argmatch.
+   KIND is a description of the type of entity that was being matched.
+   VALUE is the invalid value that was given.
+   PROBLEM is the return value from argmatch.  */
+
+void
+invalid_arg (kind, value, problem)
+     char *kind;
+     char *value;
+     int problem;
+{
+  fprintf (stderr, "%s: ", program_name);
+  if (problem == -1)
+    fprintf (stderr, "invalid");
+  else				/* Assume -2.  */
+    fprintf (stderr, "ambiguous");
+  fprintf (stderr, " %s `%s'\n", kind, value);
+}