source/core/getopt.cpp

   1 #include "getopt.h"
   2
   3 using namespace std;
   4
   5 namespace Msp {
   6
   7 GetOpt::GetOpt():
   8         help(false)
   9 {
  10         add_option("help", help, NO_ARG).set_help("Displays this help");
  11 }
  12
  13 GetOpt::~GetOpt()
  14 {
  15         for(list<OptBase *>::iterator i=opts.begin(); i!=opts.end(); ++i)
  16                 delete *i;
  17 }
  18
  19 GetOpt::OptBase &GetOpt::get_option(char s)
  20 {
  21         for(list<OptBase *>::iterator i=opts.begin(); i!=opts.end(); ++i)
  22                 if((*i)->get_short()==s)
  23                         return **i;
  24         throw usage_error(string("Unknown option -")+s);
  25 }
  26
  27 GetOpt::OptBase &GetOpt::get_option(const string &l)
  28 {
  29         for(list<OptBase *>::iterator i=opts.begin(); i!=opts.end(); ++i)
  30                 if((*i)->get_long()==l)
  31                         return **i;
  32         throw usage_error(string("Unknown option --")+l);
  33 }
  34
  35 void GetOpt::operator()(unsigned argc, const char *const *argv)
  36 {
  37         try
  38         {
  39                 unsigned i = 1;
  40                 for(; i<argc;)
  41                 {
  42                         if(argv[i][0]=='-')
  43                         {
  44                                 if(argv[i][1]=='-')
  45                                 {
  46                                         if(!argv[i][2])
  47                                                 break;
  48
  49                                         i += process_long(argv+i);
  50                                 }
  51                                 else
  52                                         i += process_short(argv+i);
  53                         }
  54                         else
  55                                 args.push_back(argv[i++]);
  56                 }
  57
  58                 for(; i<argc; ++i)
  59                         args.push_back(argv[i]);
  60         }
  61         catch(const usage_error &e)
  62         {
  63                 throw usage_error(e.what(), "Usage: "+generate_usage(argv[0]));
  64         }
  65
  66         if(help)
  67                 throw usage_error(string("Help for ")+argv[0]+":", generate_help());
  68 }
  69
  70 unsigned GetOpt::process_long(const char *const *argp)
  71 {
  72         // Skip the --
  73         const char *arg = argp[0]+2;
  74
  75         // See if the argument contains an =
  76         unsigned equals = 0;
  77         for(; arg[equals] && arg[equals]!='='; ++equals) ;
  78
  79         OptBase &opt = get_option(string(arg, equals));
  80
  81         if(arg[equals])
  82                 // Process the part after the = as option argument
  83                 opt.process(arg+equals+1);
  84         else if(opt.get_arg_type()==REQUIRED_ARG)
  85         {
  86                 if(!argp[1])
  87                         throw usage_error("--"+string(arg)+" requires an argument");
  88
  89                 // Process the next argument as option argument
  90                 opt.process(argp[1]);
  91                 return 2;
  92         }
  93         else
  94                 opt.process();
  95
  96         return 1;
  97 }
  98
  99 unsigned GetOpt::process_short(const char *const *argp)
 100 {
 101         // Skip the -
 102         const char *arg = argp[0]+1;
 103
 104         // Loop through all characters in the argument
 105         for(; *arg; ++arg)
 106         {
 107                 OptBase &opt = get_option(*arg);
 108
 109                 if(arg[1] && opt.get_arg_type()!=NO_ARG)
 110                 {
 111                         // Need an option argument and we have characters left - use them
 112                         opt.process(arg+1);
 113                         return 1;
 114                 }
 115                 else if(opt.get_arg_type()==REQUIRED_ARG)
 116                 {
 117                         if(!argp[1])
 118                                 throw usage_error("-"+string(1, *arg)+" requires an argument");
 119
 120                         // Use the next argument as option argument
 121                         opt.process(argp[1]);
 122                         return 2;
 123                 }
 124                 else
 125                         opt.process();
 126         }
 127
 128         return 1;
 129 }
 130
 131 string GetOpt::generate_usage(const string &argv0) const
 132 {
 133         ostringstream line;
 134
 135         line<<argv0;
 136         for(list<OptBase *>::const_iterator i=opts.begin(); i!=opts.end(); ++i)
 137         {
 138                 line<<" [";
 139                 if((*i)->get_short())
 140                 {
 141                         line<<'-'<<(*i)->get_short();
 142                         if(!(*i)->get_long().empty())
 143                                 line<<'|';
 144                         else if((*i)->get_arg_type()==OPTIONAL_ARG)
 145                                 line<<'['<<(*i)->get_metavar()<<']';
 146                         else if((*i)->get_arg_type()==REQUIRED_ARG)
 147                                 line<<' '<<(*i)->get_metavar();
 148                 }
 149                 if(!(*i)->get_long().empty())
 150                 {
 151                         line<<"--"<<(*i)->get_long();
 152
 153                         if((*i)->get_arg_type()==OPTIONAL_ARG)
 154                                 line<<"[="<<(*i)->get_metavar()<<']';
 155                         else if((*i)->get_arg_type()==REQUIRED_ARG)
 156                                 line<<'='<<(*i)->get_metavar();
 157                 }
 158                 line<<']';
 159         }
 160
 161         return line.str();
 162 }
 163
 164 string GetOpt::generate_help() const
 165 {
 166         bool any_short = false;
 167         for(list<OptBase *>::const_iterator i=opts.begin(); (!any_short && i!=opts.end()); ++i)
 168                 any_short = (*i)->get_short();
 169
 170         string::size_type maxw = 0;
 171         list<string> switches;
 172         for(list<OptBase *>::const_iterator i=opts.begin(); i!=opts.end(); ++i)
 173         {
 174                 ostringstream swtch;
 175                 if((*i)->get_short())
 176                 {
 177                         swtch<<'-'<<(*i)->get_short();
 178                         if(!(*i)->get_long().empty())
 179                                 swtch<<", ";
 180                         else if((*i)->get_arg_type()==OPTIONAL_ARG)
 181                                 swtch<<'['<<(*i)->get_metavar()<<']';
 182                         else if((*i)->get_arg_type()==REQUIRED_ARG)
 183                                 swtch<<' '<<(*i)->get_metavar();
 184                 }
 185                 else if(any_short)
 186                         swtch<<"    ";
 187                 if(!(*i)->get_long().empty())
 188                 {
 189                         swtch<<"--"<<(*i)->get_long();
 190
 191                         if((*i)->get_arg_type()==OPTIONAL_ARG)
 192                                 swtch<<"[="<<(*i)->get_metavar()<<']';
 193                         else if((*i)->get_arg_type()==REQUIRED_ARG)
 194                                 swtch<<'='<<(*i)->get_metavar();
 195                 }
 196                 switches.push_back(swtch.str());
 197                 maxw = max(maxw, switches.back().size());
 198         }
 199
 200         string result;
 201         list<string>::const_iterator j = switches.begin();
 202         for(list<OptBase *>::const_iterator i=opts.begin(); i!=opts.end(); ++i, ++j)
 203         {
 204                 result += "  "+*j;
 205                 result += string(maxw+2-j->size(), ' ');
 206                 result += (*i)->get_help();
 207                 result += '\n';
 208         }
 209
 210         return result;
 211 }
 212
 213
 214 GetOpt::OptBase::OptBase(char s, const std::string &l, ArgType a):
 215         shrt(s),
 216         lng(l),
 217         arg_type(a),
 218         seen_count(0),
 219         metavar("ARG")
 220 { }
 221
 222 GetOpt::OptBase &GetOpt::OptBase::set_help(const string &h)
 223 {
 224         help = h;
 225         return *this;
 226 }
 227
 228 GetOpt::OptBase &GetOpt::OptBase::set_help(const string &h, const string &m)
 229 {
 230         help = h;
 231         metavar = m;
 232         return *this;
 233 }
 234
 235 void GetOpt::OptBase::process()
 236 {
 237         if(arg_type==REQUIRED_ARG)
 238                 throw usage_error("--"+lng+" requires an argument");
 239         ++seen_count;
 240
 241         store();
 242 }
 243
 244 void GetOpt::OptBase::process(const string &arg)
 245 {
 246         if(arg_type==NO_ARG)
 247                 throw usage_error("--"+lng+" takes no argument");
 248         ++seen_count;
 249
 250         store(arg);
 251 }
 252
 253 } // namespace Msp