added option.cc and option.h

2 files changed, 183 insertions, 0 deletions

diff --git a/option.cc b/option.cc
new file mode 100644
index 00000000..586037b1
--- /dev/null
+++ b/option.cc
@@ -0,0 +1,132 @@
+#include "option.h"
+
+#include <iostream>
+#include <cstdarg>
+
+option_handler::option_handler(const std::string& label,
+			       const std::string& opt_chars,
+			       const bool         _multiple)
+  : handled(false), multiple(_multiple)
+{
+  option_t opt;
+
+  for (const char * q = label.c_str(); *q; q++)
+    if (*q == '_')
+      opt.long_opt += '-';
+    else
+      opt.long_opt += *q;
+
+  handlers.insert(option_handler_pair(opt.long_opt, this));
+
+  if (! opt_chars.empty()) {
+    if (opt_chars[0] != ':')
+      opt.short_opt = opt_chars[0];
+
+    if (opt_chars[opt_chars.length() - 1] == ':')
+      opt.wants_arg = true;
+  }
+
+  opt.handler = this;
+
+  options.push_back(opt);
+}
+
+bool process_option(const std::string& opt, const char * arg)
+{
+  option_handler_map::iterator handler = option_handler::handlers.find(opt);
+  if (handler != option_handler::handlers.end() &&
+      (! (*handler).second->handled || (*handler).second->multiple)) {
+    (*handler).second->handle_option(arg);
+    (*handler).second->handled = true;
+    return true;
+  }
+  return false;
+}
+
+static inline void process_option(const option_t& opt,
+				  const char * arg = NULL) {
+  if (! opt.handler->handled || opt.handler->multiple) {
+    opt.handler->handle_option(arg);
+    opt.handler->handled = true;
+  }
+}
+
+void process_arguments(std::vector<char *>& args, int argc, char ** argv)
+{
+  int index = 1;
+  for (char ** i = argv + 1; index < argc; i++, index++) {
+    if ((*i)[0] != '-') {
+      args.push_back(*i);
+      continue;
+    }
+
+    // --long-option
+  again:
+    if ((*i)[1] == '-') {
+      for (std::vector<option_t>::iterator j
+	     = option_handler::options.begin();
+	   j != option_handler::options.end();
+	   j++)
+	if ((*j).wants_arg) {
+	  if (const char * p = std::strchr(*i + 2, '=')) {
+	    if ((*j).long_opt == std::string(*i + 2, p - (*i + 2))) {
+	      process_option(*j, p + 1);
+	      goto next;
+	    }
+	  }
+	  else if ((*j).long_opt == *i + 2) {
+	    process_option(*j, argv[++index]);
+	    goto next;
+	  }
+	}
+	else if ((*j).long_opt == *i + 2) {
+	  process_option(*j);
+	  goto next;
+	}
+
+      std::cerr << "Error: illegal option " << *i << std::endl;
+      std::exit(1);
+    } else {
+      for (std::vector<option_t>::iterator j
+	     = option_handler::options.begin();
+	   j != option_handler::options.end();
+	   j++)
+	if ((*i)[1] == (*j).short_opt) {
+	  if ((*j).wants_arg) {
+	    process_option(*j, argv[++index]);
+	    goto next;
+	  } else {
+	    process_option(*j);
+	    if ((*i)[2]) {
+	      std::strcpy(*i + 1, *i + 2);
+	      goto again;
+	    }
+	    goto next;
+	  }
+	}
+
+      std::cerr << "Error: illegal option -- " << (*i)[1] << std::endl;
+      std::exit(1);
+    }
+
+   next:
+    ;
+  }
+}
+
+void process_environment(char ** envp)
+{
+  for (char ** p = envp; *p; p++)
+    if (std::strncmp(*p, "LEDGER_", 7) == 0) {
+      std::string opt;
+      char * q;
+      for (q = *p + 7; *q && *q != '='; q++)
+	if (*q == '_')
+	  opt += '-';
+	else
+	  opt += std::tolower(*q);
+
+      if (*q == '=')
+	process_option(opt, q + 1);
+    }
+}
diff --git a/option.h b/option.h
new file mode 100644
index 00000000..33b54933
--- /dev/null
+++ b/option.h
@@ -0,0 +1,51 @@
+#ifndef _OPTION_H
+#define _OPTION_H
+
+#include <map>
+#include <vector>
+#include <string>
+
+struct option_handler;
+
+struct option_t {
+  char		   short_opt;
+  std::string	   long_opt;
+  bool		   wants_arg;
+  option_handler * handler;
+
+  option_t() : short_opt(0), wants_arg(false) {}
+};
+
+typedef std::map<const std::string, option_handler *>  option_handler_map;
+typedef std::pair<const std::string, option_handler *> option_handler_pair;
+
+struct option_handler {
+  bool handled;
+  bool multiple;
+
+  static std::vector<option_t> options;
+  static option_handler_map    handlers;
+
+  option_handler(const std::string& label,
+		 const std::string& opt_chars,
+		 const bool         _multiple);
+
+  virtual void handle_option(const char * arg = NULL) = 0;
+};
+
+bool process_option(const std::string& opt, const char * arg = NULL);
+void process_arguments(std::vector<char *>& args, int argc, char ** argv);
+void process_environment(char ** envp);
+
+#define DEF_OPT_HANDLERS()				\
+  std::vector<option_t> option_handler::options;	\
+  option_handler_map    option_handler::handlers
+
+#define OPT_BEGIN(tag, chars, multi)				\
+  static struct tag ## _handler : public option_handler {	\
+    tag ## _handler() : option_handler(#tag, chars, multi) {}	\
+    virtual void handle_option(const char * optarg)
+
+#define OPT_END(tag) } tag ## _handler_obj
+
+#endif // _OPTION_H