src/CommandLine.h

   1 /*
   2  * Copyright (C) 1996-2023 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_SRC_COMMANDLINE_H
  10 #define SQUID_SRC_COMMANDLINE_H
  11
  12 #if HAVE_GETOPT_H
  13 #include <getopt.h>
  14 #endif
  15 #include <vector>
  16
  17 typedef struct option RawLongOption;
  18
  19 /// A struct option C++ wrapper, helps with option::name copying/freeing.
  20 class LongOption : public RawLongOption
  21 {
  22 public:
  23     LongOption();
  24     explicit LongOption(const RawLongOption &);
  25     LongOption(const LongOption&);
  26     LongOption &operator =(const LongOption &);
  27     ~LongOption();
  28
  29 private:
  30     void copy(const RawLongOption &);
  31 };
  32
  33 /// Manages arguments passed to a program (i.e., main(argc, argv) parameters).
  34 class CommandLine
  35 {
  36 public:
  37     /// expects main() input plus getopt_long(3) grammar rules for parsing argv
  38     CommandLine(int argc, char *argv[], const char *shortRules, const RawLongOption *longRules);
  39     CommandLine(const CommandLine &them);
  40     ~CommandLine();
  41
  42     CommandLine &operator =(const CommandLine &);
  43
  44     /// \returns whether the option with optId identifier is present
  45     /// When returning true, sets non-nil optValue to the found option's value.
  46     /// For letter options (-x) and their --long synonyms, the letter is the ID.
  47     /// For long-only --options, the ID is the configured options::val value.
  48     bool hasOption(const int optId, const char **optValue = nullptr) const;
  49
  50     /// A callback function for forEachOption(); receives parsed options.
  51     /// Must not call pushFrontOption(), hasOption() or forEachOption() -- getopt(3) uses globals!
  52     typedef void Visitor(const int optId, const char *optValue);
  53
  54     /// calls Visitor for each of the configured command line option
  55     void forEachOption(Visitor) const;
  56
  57     /// \returns argv[0], which is usually a program "name"
  58     const char *arg0() const { return argv_[0]; }
  59
  60     /// \returns main()'s argc, which is traditionally missing the last/nil item
  61     int argc() const { return static_cast<int>(argv_.size()) - 1; }
  62
  63     /// \returns main()'s argv[] which is traditionally const-wrong
  64     char **argv() const { return const_cast<char**>(argv_.data()); }
  65
  66     /// replaces argv[0] with the new value
  67     void resetArg0(const char *programName);
  68
  69     /// inserts a (possibly duplicated) option at the beginning of options (just after argv[0])
  70     void pushFrontOption(const char *name, const char *value = nullptr);
  71
  72 private:
  73     const RawLongOption *longOptions() const { return longOptions_.size() ? longOptions_.data() : nullptr; }
  74     bool nextOption(int &optId) const;
  75
  76     /// raw main() parameters, including argv[0] and a nil argv[argc]
  77     std::vector<char *> argv_;
  78
  79     /* getopt_long() grammar rules */
  80     const char *shortOptions_; ///< single-dash, single-letter (-x) option rules
  81     std::vector<LongOption> longOptions_; ///< long --option rules
  82 };
  83
  84 #endif /* SQUID_SRC_COMMANDLINE_H */
  85