mdw@git.distorted.org.uk Git - mLib/blob - trace/traceopt.c

   1 /* -*-c-*-
   2  *
   3  * Parsing tracing options
   4  *
   5  * (c) 1999 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include <stdio.h>
  31 #include <string.h>
  32 #include <stdlib.h>
  33
  34 #include "macros.h"
  35 #include "report.h"
  36 #include "trace.h"
  37
  38 /*----- Main code ---------------------------------------------------------*/
  39
  40 /* --- @traceopt@ --- *
  41  *
  42  * Arguments:   @const trace_opt *t@ = pointer to trace options table
  43  *              @const char *p@ = option string supplied by user
  44  *              @unsigned f@ = initial tracing flags
  45  *              @unsigned bad@ = forbidden tracing flags
  46  *
  47  * Returns:     Trace flags as set by user.
  48  *
  49  * Use:         Parses an option string from the user and sets the
  50  *              appropriate trace flags.  If the argument is null or a single
  51  *              `?' character, a help message is displayed.
  52  */
  53
  54 unsigned traceopt(const trace_opt *t, const char *p,
  55                   unsigned f, unsigned bad)
  56 {
  57   unsigned sense = 1;
  58
  59   /* --- Dump out help text --- */
  60
  61   if (!p || STRCMP(p, ==, "?")) {
  62     const trace_opt *tt;
  63     puts("Trace options:");
  64     for (tt = t; tt->ch; tt++) {
  65       if (!(tt->f & ~bad) || !tt->help)
  66         continue;
  67       printf("  `%c': %s\n", tt->ch, tt->help);
  68     }
  69     return (f);
  70   }
  71
  72   /* --- Parse the string properly --- */
  73
  74   f = 0;
  75   while (*p) {
  76     switch (*p) {
  77       case '+':
  78         sense = 1;
  79         break;
  80       case '-':
  81         sense = 0;
  82         break;
  83       default: {
  84         const trace_opt *tt;
  85         for (tt = t; tt->ch; tt++) {
  86           if (!(tt->f & ~bad))
  87             continue;
  88           if (tt->ch == *p) {
  89             if (sense)
  90               f |= (tt->f & ~bad);
  91             else
  92               f &= ~(tt->f & ~bad);
  93             goto ok;
  94           }
  95         }
  96         moan("unknown trace option `%c'", *p);
  97       ok:;
  98       } break;
  99     }
 100     p++;
 101   }
 102
 103   return (f);
 104 }
 105
 106 /*----- That's all, folks -------------------------------------------------*/