Separate function for parsing user trace specs.

[mLib] / traceopt.c

diff --git a/traceopt.c b/traceopt.c
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+/* -*-c-*-
+ *
+ * $Id: traceopt.c,v 1.1 1999/10/22 22:40:08 mdw Exp $
+ *
+ * Parsing tracing options
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------* 
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ * 
+ * mLib 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 Library General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: traceopt.c,v $
+ * Revision 1.1  1999/10/22 22:40:08  mdw
+ * Separate function for parsing user trace specs.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "report.h"
+#include "trace.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @traceopt@ --- *
+ *
+ * Arguments:  @trace_opt *t@ = pointer to trace options table
+ *             @const char *p@ = option string supplied by user
+ *             @unsigned f@ = initial tracing flags
+ *             @unsigned bad@ = forbidden tracing flags
+ *
+ * Returns:    Trace flags as set by user.
+ *
+ * Use:                Parses an option string from the user and sets the
+ *             appropriate trace flags.  If the argument is null or a single
+ *             `?' character, a help message is displayed.
+ */
+
+unsigned traceopt(trace_opt *t, const char *p, unsigned f, unsigned bad)
+{
+  unsigned sense = 1;
+
+  /* --- Dump out help text --- */
+
+  if (!p || strcmp(p, "?")) {
+    puts("Trace options:");
+    while (t->ch) {
+      if (t->f & bad || !t->help)
+       continue;
+      printf("  `%c': %s\n", t->ch, t->help);
+    }
+    return (f);
+  }
+
+  /* --- Parse the string properly --- */
+
+  f = 0;
+  while (*p) {
+    switch (*p) {
+      case '+':
+       sense = 1;
+       break;
+      case '-':
+       sense = 0;
+       break;
+      default: {
+       trace_opt *tt;
+       for (tt = t; tt->ch; tt++) {
+         if (tt->f & bad)
+           continue;
+         if (tt->ch == *p) {
+           if (sense)
+             f |= (tt->f & ~bad);
+           else
+             f &= ~(tt->f & ~bad);
+         }
+         goto ok;
+       }
+       moan("unknown trace option `%c'", *p);
+      ok:;
+      } break;
+    }
+    p++;
+  }
+
+  return (f);
+}
+
+/*----- That's all, folks -------------------------------------------------*/