src/misc/getoptdata.cpp

   1 /* $Id: getoptdata.cpp 23245 2011-11-17 21:18:24Z rubidium $ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD 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, version 2.
   6  * OpenTTD 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.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file getoptdata.cpp Library for parsing command line options. */
  11
  12 #include "../stdafx.h"
  13 #include "getoptdata.h"
  14
  15 #include "../safeguards.h"
  16
  17 /**
  18  * Find the next option.
  19  * @return Function returns one
  20  * - An option letter if it found another option.
  21  * - -1 if option processing is finished. Inspect #argv and #numleft to find the command line arguments.
  22  * - -2 if an error was encountered.
  23  */
  24 int GetOptData::GetOpt()
  25 {
  26         const OptionData *odata;
  27
  28         char *s = this->cont;
  29         if (s == NULL) {
  30                 if (this->numleft == 0) return -1; // No arguments left -> finished.
  31
  32                 s = this->argv[0];
  33                 if (*s != '-') return -1; // No leading '-' -> not an option -> finished.
  34
  35                 this->argv++;
  36                 this->numleft--;
  37
  38                 /* Is it a long option? */
  39                 for (odata = this->options; odata->flags != ODF_END; odata++) {
  40                         if (odata->longname != NULL && !strcmp(odata->longname, s)) { // Long options always use the entire argument.
  41                                 this->cont = NULL;
  42                                 goto set_optval;
  43                         }
  44                 }
  45
  46                 s++; // Skip leading '-'.
  47         }
  48
  49         /* Is it a short option? */
  50         for (odata = this->options; odata->flags != ODF_END; odata++) {
  51                 if (odata->shortname != '\0' && *s == odata->shortname) {
  52                         this->cont = (s[1] != '\0') ? s + 1 : NULL;
  53
  54 set_optval: // Handle option value of *odata .
  55                         this->opt = NULL;
  56                         switch (odata->flags) {
  57                                 case ODF_NO_VALUE:
  58                                         return odata->id;
  59
  60                                 case ODF_HAS_VALUE:
  61                                 case ODF_OPTIONAL_VALUE:
  62                                         if (this->cont != NULL) { // Remainder of the argument is the option value.
  63                                                 this->opt = this->cont;
  64                                                 this->cont = NULL;
  65                                                 return odata->id;
  66                                         }
  67                                         /* No more arguments, either return an error or a value-less option. */
  68                                         if (this->numleft == 0) return (odata->flags == ODF_HAS_VALUE) ? -2 : odata->id;
  69
  70                                         /* Next argument looks like another option, let's not return it as option value. */
  71                                         if (odata->flags == ODF_OPTIONAL_VALUE && this->argv[0][0] == '-') return odata->id;
  72
  73                                         this->opt = this->argv[0]; // Next argument is the option value.
  74                                         this->argv++;
  75                                         this->numleft--;
  76                                         return odata->id;
  77
  78                                 default: NOT_REACHED();
  79                         }
  80                 }
  81         }
  82
  83         return -2; // No other ways to interpret the text -> error.
  84 }
  85