src/CommandLine.cc

   1 /*
   2  * Copyright (C) 1996-2020 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 #include "squid.h"
  10
  11 #include "CommandLine.h"
  12 #include "sbuf/SBuf.h"
  13
  14 static void
  15 ResetGetopt(const bool allowStderrWarnings)
  16 {
  17     opterr = allowStderrWarnings;
  18     // Resetting optind to zero instead of conventional '1' has an
  19     // advantage, since it also resets getopt(3) global state.
  20     // getopt(3) always skips argv[0], even if optind is zero
  21     optind = 0;
  22 }
  23
  24 CommandLine::CommandLine(int argC, char *argV[], const char *shortRules, const RawLongOption *longRules):
  25     argv_(),
  26     shortOptions_(shortRules ? xstrdup(shortRules) : ""),
  27     longOptions_()
  28 {
  29     assert(argC > 0); // C++ main() requirement that makes our arg0() safe
  30     assert(shortRules);
  31
  32     /* copy argV items */
  33     argv_.reserve(argC+1);
  34     for (int i = 0; i < argC; ++i)
  35         argv_.push_back(xstrdup(argV[i]));
  36     argv_.push_back(nullptr); // POSIX argv "must be terminated by a null pointer"
  37
  38     /* copy grammar rules for the long options */
  39     if (longRules) {
  40         for (auto longOption = longRules; longOption->name; ++longOption)
  41             longOptions_.emplace_back(*longOption);
  42         longOptions_.emplace_back();
  43     }
  44 }
  45
  46 CommandLine::CommandLine(const CommandLine &them):
  47     CommandLine(them.argc(), them.argv(), them.shortOptions_, them.longOptions())
  48 {
  49 }
  50
  51 CommandLine &
  52 CommandLine::operator =(const CommandLine &them)
  53 {
  54     // cannot just swap(*this, them): std::swap(T,T) may call this assignment op
  55     CommandLine tmp(them);
  56     std::swap(argv_, tmp.argv_);
  57     std::swap(shortOptions_, tmp.shortOptions_);
  58     std::swap(longOptions_, tmp.longOptions_);
  59     return *this;
  60 }
  61
  62 CommandLine::~CommandLine()
  63 {
  64     for (auto arg: argv_)
  65         xfree(arg);
  66
  67     xfree(shortOptions_);
  68 }
  69
  70 bool
  71 CommandLine::hasOption(const int optIdToFind, const char **optValue) const
  72 {
  73     ResetGetopt(false); // avoid duped warnings; forEachOption() will complain
  74     int optId = 0;
  75     while (nextOption(optId)) {
  76         if (optId == optIdToFind) {
  77             if (optValue) {
  78                 // do not need to copy the optarg string because it is a pointer into the original
  79                 // argv array (https://www.gnu.org/software/libc/manual/html_node/Using-Getopt.html)
  80                 *optValue = optarg;
  81             }
  82             return true;
  83         }
  84     }
  85     return false;
  86 }
  87
  88 void
  89 CommandLine::forEachOption(Visitor visitor) const
  90 {
  91     ResetGetopt(true);
  92     int optId = 0;
  93     while (nextOption(optId))
  94         visitor(optId, optarg);
  95 }
  96
  97 /// extracts the next option (if any)
  98 /// \returns whether the option was extracted
  99 /// throws on unknown option or missing required argument
 100 bool
 101 CommandLine::nextOption(int &optId) const
 102 {
 103     optId = getopt_long(argc(), argv(), shortOptions_, longOptions(), nullptr);
 104     if ((optId == ':' && shortOptions_[0] == ':') || optId == '?') {
 105         assert(optind > 0 && static_cast<unsigned int>(optind) < argv_.size());
 106         SBuf errMsg;
 107         errMsg.Printf("'%s': %s", argv_[optind - 1],  optId == '?' ?
 108                       "unrecognized option or missing required argument" : "missing required argument");
 109         throw TexcHere(errMsg);
 110     }
 111     return optId != -1;
 112 }
 113
 114 void
 115 CommandLine::resetArg0(const char *programName)
 116 {
 117     assert(programName);
 118     xfree(argv_[0]);
 119     argv_[0] = xstrdup(programName);
 120 }
 121
 122 void
 123 CommandLine::pushFrontOption(const char *name, const char *value)
 124 {
 125     assert(name);
 126     argv_.insert(argv_.begin() + 1, xstrdup(name));
 127     if (value)
 128         argv_.insert(argv_.begin() + 2, xstrdup(value));
 129 }
 130
 131 LongOption::LongOption() :
 132     option({nullptr, 0, nullptr, 0})
 133 {
 134 }
 135
 136 LongOption::LongOption(const RawLongOption &opt) :
 137     option({nullptr, 0, nullptr, 0})
 138 {
 139     copy(opt);
 140 }
 141
 142 LongOption::LongOption(const LongOption &opt):
 143     LongOption(static_cast<const RawLongOption &>(opt))
 144 {
 145 }
 146
 147 LongOption::~LongOption()
 148 {
 149     xfree(name);
 150 }
 151
 152 LongOption &
 153 LongOption::operator =(const LongOption &opt)
 154 {
 155     if (this != &opt)
 156         copy(static_cast<const RawLongOption &>(opt));
 157     return *this;
 158 }
 159
 160 void
 161 LongOption::copy(const RawLongOption &opt)
 162 {
 163     xfree(name);
 164     name = opt.name ? xstrdup(opt.name) : nullptr;
 165     has_arg = opt.has_arg;
 166     flag = opt.flag;
 167     val = opt.val;
 168 }
 169