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Mephisto/optionparser.h
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/*
* The Lean Mean C++ Option Parser
*
* Copyright (C) 2012-2017 Matthias S. Benkmann
*
* The "Software" in the following 2 paragraphs refers to this file containing
* the code to The Lean Mean C++ Option Parser.
* The "Software" does NOT refer to any other files which you
* may have received alongside this file (e.g. as part of a larger project that
* incorporates The Lean Mean C++ Option Parser).
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software, to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to permit
* persons to whom the Software is furnished to do so, subject to the following
* conditions:
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/*
* NOTE: It is recommended that you read the processed HTML doxygen documentation
* rather than this source. If you don't know doxygen, it's like javadoc for C++.
* If you don't want to install doxygen you can find a copy of the processed
* documentation at
*
* http://optionparser.sourceforge.net/
*
*/
/**
* @file
*
* @brief This is the only file required to use The Lean Mean C++ Option Parser.
* Just \#include it and you're set.
*
* The Lean Mean C++ Option Parser handles the program's command line arguments
* (argc, argv).
* It supports the short and long option formats of getopt(), getopt_long()
* and getopt_long_only() but has a more convenient interface.
*
* @par Feedback:
* Send questions, bug reports, feature requests etc. to: <tt><b>optionparser-feedback(a)lists.sourceforge.net</b></tt>
*
* @par Highlights:
* <ul style="padding-left:1em;margin-left:0">
* <li> It is a header-only library. Just <code>\#include "optionparser.h"</code> and you're set.
* <li> It is freestanding. There are no dependencies whatsoever, not even the
* C or C++ standard library.
* <li> It has a usage message formatter that supports column alignment and
* line wrapping. This aids localization because it adapts to
* translated strings that are shorter or longer (even if they contain
* Asian wide characters).
* <li> Unlike getopt() and derivatives it doesn't force you to loop through
* options sequentially. Instead you can access options directly like this:
* <ul style="margin-top:.5em">
* <li> Test for presence of a switch in the argument vector:
* @code if ( options[QUIET] ) ... @endcode
* <li> Evaluate --enable-foo/--disable-foo pair where the last one used wins:
* @code if ( options[FOO].last()->type() == DISABLE ) ... @endcode
* <li> Cumulative option (-v verbose, -vv more verbose, -vvv even more verbose):
* @code int verbosity = options[VERBOSE].count(); @endcode
* <li> Iterate over all --file=&lt;fname> arguments:
* @code for (Option* opt = options[FILE]; opt; opt = opt->next())
* fname = opt->arg; ... @endcode
* <li> If you really want to, you can still process all arguments in order:
* @code
* for (int i = 0; i < p.optionsCount(); ++i) {
* Option& opt = buffer[i];
* switch(opt.index()) {
* case HELP: ...
* case VERBOSE: ...
* case FILE: fname = opt.arg; ...
* case UNKNOWN: ...
* @endcode
* </ul>
* </ul> @n
* Despite these features the code size remains tiny.
* It is smaller than <a href="http://uclibc.org">uClibc</a>'s GNU getopt() and just a
* couple 100 bytes larger than uClibc's SUSv3 getopt(). @n
* (This does not include the usage formatter, of course. But you don't have to use that.)
*
* @par Download:
* Tarball with examples and test programs:
* <a style="font-size:larger;font-weight:bold" href="http://sourceforge.net/projects/optionparser/files/optionparser-1.6.tar.gz/download">optionparser-1.6.tar.gz</a> @n
* Just the header (this is all you really need):
* <a style="font-size:larger;font-weight:bold" href="http://optionparser.sourceforge.net/optionparser.h">optionparser.h</a>
*
* @par Changelog:
* <b>Version 1.6:</b> Fix for MSC compiler. @n
* <b>Version 1.5:</b> Fixed 2 warnings about potentially uninitialized variables. @n
* Added const version of Option::next(). @n
* <b>Version 1.4:</b> Fixed 2 printUsage() bugs that messed up output with small COLUMNS values. @n
* <b>Version 1.3:</b> Compatible with Microsoft Visual C++. @n
* <b>Version 1.2:</b> Added @ref option::Option::namelen "Option::namelen" and removed the extraction
* of short option characters into a special buffer. @n
* Changed @ref option::Arg::Optional "Arg::Optional" to accept arguments if they are attached
* rather than separate. This is what GNU getopt() does and how POSIX recommends
* utilities should interpret their arguments.@n
* <b>Version 1.1:</b> Optional mode with argument reordering as done by GNU getopt(), so that
* options and non-options can be mixed. See
* @ref option::Parser::parse() "Parser::parse()".
*
*
* @par Example program:
* (Note: @c option::* identifiers are links that take you to their documentation.)
* @code
* #error EXAMPLE SHORTENED FOR READABILITY. BETTER EXAMPLES ARE IN THE .TAR.GZ!
* #include <iostream>
* #include "optionparser.h"
*
* enum optionIndex { UNKNOWN, HELP, PLUS };
* const option::Descriptor usage[] =
* {
* {UNKNOWN, 0,"" , "" ,option::Arg::None, "USAGE: example [options]\n\n"
* "Options:" },
* {HELP, 0,"" , "help",option::Arg::None, " --help \tPrint usage and exit." },
* {PLUS, 0,"p", "plus",option::Arg::None, " --plus, -p \tIncrement count." },
* {UNKNOWN, 0,"" , "" ,option::Arg::None, "\nExamples:\n"
* " example --unknown -- --this_is_no_option\n"
* " example -unk --plus -ppp file1 file2\n" },
* {0,0,0,0,0,0}
* };
*
* int main(int argc, char* argv[])
* {
* argc-=(argc>0); argv+=(argc>0); // skip program name argv[0] if present
* option::Stats stats(usage, argc, argv);
* option::Option options[stats.options_max], buffer[stats.buffer_max];
* option::Parser parse(usage, argc, argv, options, buffer);
*
* if (parse.error())
* return 1;
*
* if (options[HELP] || argc == 0) {
* option::printUsage(std::cout, usage);
* return 0;
* }
*
* std::cout << "--plus count: " <<
* options[PLUS].count() << "\n";
*
* for (option::Option* opt = options[UNKNOWN]; opt; opt = opt->next())
* std::cout << "Unknown option: " << opt->name << "\n";
*
* for (int i = 0; i < parse.nonOptionsCount(); ++i)
* std::cout << "Non-option #" << i << ": " << parse.nonOption(i) << "\n";
* }
* @endcode
*
* @par Option syntax:
* @li The Lean Mean C++ Option Parser follows POSIX <code>getopt()</code> conventions and supports
* GNU-style <code>getopt_long()</code> long options as well as Perl-style single-minus
* long options (<code>getopt_long_only()</code>).
* @li short options have the format @c -X where @c X is any character that fits in a char.
* @li short options can be grouped, i.e. <code>-X -Y</code> is equivalent to @c -XY.
* @li a short option may take an argument either separate (<code>-X foo</code>) or
* attached (@c -Xfoo). You can make the parser accept the additional format @c -X=foo by
* registering @c X as a long option (in addition to being a short option) and
* enabling single-minus long options.
* @li an argument-taking short option may be grouped if it is the last in the group, e.g.
* @c -ABCXfoo or <code> -ABCX foo </code> (@c foo is the argument to the @c -X option).
* @li a lone minus character @c '-' is not treated as an option. It is customarily used where
* a file name is expected to refer to stdin or stdout.
* @li long options have the format @c --option-name.
* @li the option-name of a long option can be anything and include any characters.
* Even @c = characters will work, but don't do that.
* @li [optional] long options may be abbreviated as long as the abbreviation is unambiguous.
* You can set a minimum length for abbreviations.
* @li [optional] long options may begin with a single minus. The double minus form is always
* accepted, too.
* @li a long option may take an argument either separate (<code> --option arg </code>) or
* attached (<code> --option=arg </code>). In the attached form the equals sign is mandatory.
* @li an empty string can be passed as an attached long option argument: <code> --option-name= </code>.
* Note the distinction between an empty string as argument and no argument at all.
* @li an empty string is permitted as separate argument to both long and short options.
* @li Arguments to both short and long options may start with a @c '-' character. E.g.
* <code> -X-X </code>, <code>-X -X</code> or <code> --long-X=-X </code>. If @c -X
* and @c --long-X take an argument, that argument will be @c "-X" in all 3 cases.
* @li If using the built-in @ref option::Arg::Optional "Arg::Optional", optional arguments must
* be attached.
* @li the special option @c -- (i.e. without a name) terminates the list of
* options. Everything that follows is a non-option argument, even if it starts with
* a @c '-' character. The @c -- itself will not appear in the parse results.
* @li the first argument that doesn't start with @c '-' or @c '--' and does not belong to
* a preceding argument-taking option, will terminate the option list and is the
* first non-option argument. All following command line arguments are treated as
* non-option arguments, even if they start with @c '-' . @n
* NOTE: This behaviour is mandated by POSIX, but GNU getopt() only honours this if it is
* explicitly requested (e.g. by setting POSIXLY_CORRECT). @n
* You can enable the GNU behaviour by passing @c true as first argument to
* e.g. @ref option::Parser::parse() "Parser::parse()".
* @li Arguments that look like options (i.e. @c '-' followed by at least 1 character) but
* aren't, are NOT treated as non-option arguments. They are treated as unknown options and
* are collected into a list of unknown options for error reporting. @n
* This means that in order to pass a first non-option
* argument beginning with the minus character it is required to use the
* @c -- special option, e.g.
* @code
* program -x -- --strange-filename
* @endcode
* In this example, @c --strange-filename is a non-option argument. If the @c --
* were omitted, it would be treated as an unknown option. @n
* See @ref option::Descriptor::longopt for information on how to collect unknown options.
*
*/
#ifndef OPTIONPARSER_H_
#define OPTIONPARSER_H_
#ifdef _MSC_VER
#include <intrin.h>
#pragma intrinsic(_BitScanReverse)
#endif
/** @brief The namespace of The Lean Mean C++ Option Parser. */
namespace option
{
#ifdef _MSC_VER
struct MSC_Builtin_CLZ
{
static int builtin_clz(unsigned x)
{
unsigned long index;
_BitScanReverse(&index, x);
return 32-index; // int is always 32bit on Windows, even for target x64
}
};
#define __builtin_clz(x) MSC_Builtin_CLZ::builtin_clz(x)
#endif
class Option;
/**
* @brief Possible results when checking if an argument is valid for a certain option.
*
* In the case that no argument is provided for an option that takes an
* optional argument, return codes @c ARG_OK and @c ARG_IGNORE are equivalent.
*/
enum ArgStatus
{
//! The option does not take an argument.
ARG_NONE,
//! The argument is acceptable for the option.
ARG_OK,
//! The argument is not acceptable but that's non-fatal because the option's argument is optional.
ARG_IGNORE,
//! The argument is not acceptable and that's fatal.
ARG_ILLEGAL
};
/**
* @brief Signature of functions that check if an argument is valid for a certain type of option.
*
* Every Option has such a function assigned in its Descriptor.
* @code
* Descriptor usage[] = { {UNKNOWN, 0, "", "", Arg::None, ""}, ... };
* @endcode
*
* A CheckArg function has the following signature:
* @code ArgStatus CheckArg(const Option& option, bool msg); @endcode
*
* It is used to check if a potential argument would be acceptable for the option.
* It will even be called if there is no argument. In that case @c option.arg will be @c NULL.
*
* If @c msg is @c true and the function determines that an argument is not acceptable and
* that this is a fatal error, it should output a message to the user before
* returning @ref ARG_ILLEGAL. If @c msg is @c false the function should remain silent (or you
* will get duplicate messages).
*
* See @ref ArgStatus for the meaning of the return values.
*
* While you can provide your own functions,
* often the following pre-defined checks (which never return @ref ARG_ILLEGAL) will suffice:
*
* @li @c Arg::None @copybrief Arg::None
* @li @c Arg::Optional @copybrief Arg::Optional
*
*/
typedef ArgStatus (*CheckArg)(const Option& option, bool msg);
/**
* @brief Describes an option, its help text (usage) and how it should be parsed.
*
* The main input when constructing an option::Parser is an array of Descriptors.
* @par Example:
* @code
* enum OptionIndex {CREATE, ...};
* enum OptionType {DISABLE, ENABLE, OTHER};
*
* const option::Descriptor usage[] = {
* { CREATE, // index
* OTHER, // type
* "c", // shortopt
* "create", // longopt
* Arg::None, // check_arg
* "--create Tells the program to create something." // help
* }
* , ...
* };
* @endcode
*/
struct Descriptor
{
/**
* @brief Index of this option's linked list in the array filled in by the parser.
*
* Command line options whose Descriptors have the same index will end up in the same
* linked list in the order in which they appear on the command line. If you have
* multiple long option aliases that refer to the same option, give their descriptors
* the same @c index.
*
* If you have options that mean exactly opposite things
* (e.g. @c --enable-foo and @c --disable-foo ), you should also give them the same
* @c index, but distinguish them through different values for @ref type.
* That way they end up in the same list and you can just take the last element of the
* list and use its type. This way you get the usual behaviour where switches later
* on the command line override earlier ones without having to code it manually.
*
* @par Tip:
* Use an enum rather than plain ints for better readability, as shown in the example
* at Descriptor.
*/
const unsigned index;
/**
* @brief Used to distinguish between options with the same @ref index.
* See @ref index for details.
*
* It is recommended that you use an enum rather than a plain int to make your
* code more readable.
*/
const int type;
/**
* @brief Each char in this string will be accepted as a short option character.
*
* The string must not include the minus character @c '-' or you'll get undefined
* behaviour.
*
* If this Descriptor should not have short option characters, use the empty
* string "". NULL is not permitted here!
*
* See @ref longopt for more information.
*/
const char* const shortopt;
/**
* @brief The long option name (without the leading @c -- ).
*
* If this Descriptor should not have a long option name, use the empty
* string "". NULL is not permitted here!
*
* While @ref shortopt allows multiple short option characters, each
* Descriptor can have only a single long option name. If you have multiple
* long option names referring to the same option use separate Descriptors
* that have the same @ref index and @ref type. You may repeat
* short option characters in such an alias Descriptor but there's no need to.
*
* @par Dummy Descriptors:
* You can use dummy Descriptors with an
* empty string for both @ref shortopt and @ref longopt to add text to
* the usage that is not related to a specific option. See @ref help.
* The first dummy Descriptor will be used for unknown options (see below).
*
* @par Unknown Option Descriptor:
* The first dummy Descriptor in the list of Descriptors,
* whose @ref shortopt and @ref longopt are both the empty string, will be used
* as the Descriptor for unknown options. An unknown option is a string in
* the argument vector that is not a lone minus @c '-' but starts with a minus
* character and does not match any Descriptor's @ref shortopt or @ref longopt. @n
* Note that the dummy descriptor's @ref check_arg function @e will be called and
* its return value will be evaluated as usual. I.e. if it returns @ref ARG_ILLEGAL
* the parsing will be aborted with <code>Parser::error()==true</code>. @n
* if @c check_arg does not return @ref ARG_ILLEGAL the descriptor's
* @ref index @e will be used to pick the linked list into which
* to put the unknown option. @n
* If there is no dummy descriptor, unknown options will be dropped silently.
*
*/
const char* const longopt;
/**
* @brief For each option that matches @ref shortopt or @ref longopt this function
* will be called to check a potential argument to the option.
*
* This function will be called even if there is no potential argument. In that case
* it will be passed @c NULL as @c arg parameter. Do not confuse this with the empty
* string.
*
* See @ref CheckArg for more information.
*/
const CheckArg check_arg;
/**
* @brief The usage text associated with the options in this Descriptor.
*
* You can use option::printUsage() to format your usage message based on
* the @c help texts. You can use dummy Descriptors where
* @ref shortopt and @ref longopt are both the empty string to add text to
* the usage that is not related to a specific option.
*
* See option::printUsage() for special formatting characters you can use in
* @c help to get a column layout.
*
* @attention
* Must be UTF-8-encoded. If your compiler supports C++11 you can use the "u8"
* prefix to make sure string literals are properly encoded.
*/
const char* help;
};
/**
* @brief A parsed option from the command line together with its argument if it has one.
*
* The Parser chains all parsed options with the same Descriptor::index together
* to form a linked list. This allows you to easily implement all of the common ways
* of handling repeated options and enable/disable pairs.
*
* @li Test for presence of a switch in the argument vector:
* @code if ( options[QUIET] ) ... @endcode
* @li Evaluate --enable-foo/--disable-foo pair where the last one used wins:
* @code if ( options[FOO].last()->type() == DISABLE ) ... @endcode
* @li Cumulative option (-v verbose, -vv more verbose, -vvv even more verbose):
* @code int verbosity = options[VERBOSE].count(); @endcode
* @li Iterate over all --file=&lt;fname> arguments:
* @code for (Option* opt = options[FILE]; opt; opt = opt->next())
* fname = opt->arg; ... @endcode
*/
class Option
{
Option* next_;
Option* prev_;
public:
/**
* @brief Pointer to this Option's Descriptor.
*
* Remember that the first dummy descriptor (see @ref Descriptor::longopt) is used
* for unknown options.
*
* @attention
* @c desc==NULL signals that this Option is unused. This is the default state of
* elements in the result array. You don't need to test @c desc explicitly. You
* can simply write something like this:
* @code
* if (options[CREATE])
* {
* ...
* }
* @endcode
* This works because of <code> operator const Option*() </code>.
*/
const Descriptor* desc;
/**
* @brief The name of the option as used on the command line.
*
* The main purpose of this string is to be presented to the user in messages.
*
* In the case of a long option, this is the actual @c argv pointer, i.e. the first
* character is a '-'. In the case of a short option this points to the option
* character within the @c argv string.
*
* Note that in the case of a short option group or an attached option argument, this
* string will contain additional characters following the actual name. Use @ref namelen
* to filter out the actual option name only.
*
*/
const char* name;
/**
* @brief Pointer to this Option's argument (if any).
*
* NULL if this option has no argument. Do not confuse this with the empty string which
* is a valid argument.
*/
const char* arg;
/**
* @brief The length of the option @ref name.
*
* Because @ref name points into the actual @c argv string, the option name may be
* followed by more characters (e.g. other short options in the same short option group).
* This value is the number of bytes (not characters!) that are part of the actual name.
*
* For a short option, this length is always 1. For a long option this length is always
* at least 2 if single minus long options are permitted and at least 3 if they are disabled.
*
* @note
* In the pathological case of a minus within a short option group (e.g. @c -xf-z), this
* length is incorrect, because this case will be misinterpreted as a long option and the
* name will therefore extend to the string's 0-terminator or a following '=" character
* if there is one. This is irrelevant for most uses of @ref name and @c namelen. If you
* really need to distinguish the case of a long and a short option, compare @ref name to
* the @c argv pointers. A long option's @c name is always identical to one of them,
* whereas a short option's is never.
*/
int namelen;
/**
* @brief Returns Descriptor::type of this Option's Descriptor, or 0 if this Option
* is invalid (unused).
*
* Because this method (and last(), too) can be used even on unused Options with desc==0, you can (provided
* you arrange your types properly) switch on type() without testing validity first.
* @code
* enum OptionType { UNUSED=0, DISABLED=0, ENABLED=1 };
* enum OptionIndex { FOO };
* const Descriptor usage[] = {
* { FOO, ENABLED, "", "enable-foo", Arg::None, 0 },
* { FOO, DISABLED, "", "disable-foo", Arg::None, 0 },
* { 0, 0, 0, 0, 0, 0 } };
* ...
* switch(options[FOO].last()->type()) // no validity check required!
* {
* case ENABLED: ...
* case DISABLED: ... // UNUSED==DISABLED !
* }
* @endcode
*/
int type() const
{
return desc == nullptr ? 0 : desc->type;
}
/**
* @brief Returns Descriptor::index of this Option's Descriptor, or -1 if this Option
* is invalid (unused).
*/
int index() const
{
return desc == nullptr ? -1 : (int)desc->index;
}
/**
* @brief Returns the number of times this Option (or others with the same Descriptor::index)
* occurs in the argument vector.
*
* This corresponds to the number of elements in the linked list this Option is part of.
* It doesn't matter on which element you call count(). The return value is always the same.
*
* Use this to implement cumulative options, such as -v, -vv, -vvv for
* different verbosity levels.
*
* Returns 0 when called for an unused/invalid option.
*/
int count()
{
int c = (desc == nullptr ? 0 : 1);
Option* p = first();
while (!p->isLast())
{
++c;
p = p->next_;
};
return c;
}
/**
* @brief Returns true iff this is the first element of the linked list.
*
* The first element in the linked list is the first option on the command line
* that has the respective Descriptor::index value.
*
* Returns true for an unused/invalid option.
*/
bool isFirst() const
{
return isTagged(prev_);
}
/**
* @brief Returns true iff this is the last element of the linked list.
*
* The last element in the linked list is the last option on the command line
* that has the respective Descriptor::index value.
*
* Returns true for an unused/invalid option.
*/
bool isLast() const
{
return isTagged(next_);
}
/**
* @brief Returns a pointer to the first element of the linked list.
*
* Use this when you want the first occurrence of an option on the command line to
* take precedence. Note that this is not the way most programs handle options.
* You should probably be using last() instead.
*
* @note
* This method may be called on an unused/invalid option and will return a pointer to the
* option itself.
*/
Option* first()
{
Option* p = this;
while (!p->isFirst())
p = p->prev_;
return p;
}
/**
* @brief Returns a pointer to the last element of the linked list.
*
* Use this when you want the last occurrence of an option on the command line to
* take precedence. This is the most common way of handling conflicting options.
*
* @note
* This method may be called on an unused/invalid option and will return a pointer to the
* option itself.
*
* @par Tip:
* If you have options with opposite meanings (e.g. @c --enable-foo and @c --disable-foo), you
* can assign them the same Descriptor::index to get them into the same list. Distinguish them by
* Descriptor::type and all you have to do is check <code> last()->type() </code> to get
* the state listed last on the command line.
*/
Option* last()
{
return first()->prevwrap();
}
/**
* @brief Returns a pointer to the previous element of the linked list or NULL if
* called on first().
*
* If called on first() this method returns NULL. Otherwise it will return the
* option with the same Descriptor::index that precedes this option on the command
* line.
*/
Option* prev()
{
return isFirst() ? nullptr : prev_;
}
/**
* @brief Returns a pointer to the previous element of the linked list with wrap-around from
* first() to last().
*
* If called on first() this method returns last(). Otherwise it will return the
* option with the same Descriptor::index that precedes this option on the command
* line.
*/
Option* prevwrap()
{
return untag(prev_);
}
/**
* @brief Returns a pointer to the next element of the linked list or NULL if called
* on last().
*
* If called on last() this method returns NULL. Otherwise it will return the
* option with the same Descriptor::index that follows this option on the command
* line.
*/
Option* next()
{
return isLast() ? nullptr : next_;
}
/**
* const version of Option::next().
*/
const Option* next() const
{
return isLast() ? nullptr : next_;
}
/**
* @brief Returns a pointer to the next element of the linked list with wrap-around from
* last() to first().
*
* If called on last() this method returns first(). Otherwise it will return the
* option with the same Descriptor::index that follows this option on the command
* line.
*/
Option* nextwrap()
{
return untag(next_);
}
/**
* @brief Makes @c new_last the new last() by chaining it into the list after last().
*
* It doesn't matter which element you call append() on. The new element will always
* be appended to last().
*
* @attention
* @c new_last must not yet be part of a list, or that list will become corrupted, because
* this method does not unchain @c new_last from an existing list.
*/
void append(Option* new_last)
{
Option* p = last();
Option* f = first();
p->next_ = new_last;
new_last->prev_ = p;
new_last->next_ = tag(f);
f->prev_ = tag(new_last);
}
/**
* @brief Casts from Option to const Option* but only if this Option is valid.
*
* If this Option is valid (i.e. @c desc!=NULL), returns this.
* Otherwise returns NULL. This allows testing an Option directly
* in an if-clause to see if it is used:
* @code
* if (options[CREATE])
* {
* ...
* }
* @endcode
* It also allows you to write loops like this:
* @code for (Option* opt = options[FILE]; opt; opt = opt->next())
* fname = opt->arg; ... @endcode
*/
operator const Option*() const
{
return desc ? this : nullptr;
}
/**
* @brief Casts from Option to Option* but only if this Option is valid.
*
* If this Option is valid (i.e. @c desc!=NULL), returns this.
* Otherwise returns NULL. This allows testing an Option directly
* in an if-clause to see if it is used:
* @code
* if (options[CREATE])
* {
* ...
* }
* @endcode
* It also allows you to write loops like this:
* @code for (Option* opt = options[FILE]; opt; opt = opt->next())
* fname = opt->arg; ... @endcode
*/
operator Option*()
{
return desc ? this : nullptr;
}
/**
* @brief Creates a new Option that is a one-element linked list and has NULL
* @ref desc, @ref name, @ref arg and @ref namelen.
*/
Option() :
desc(nullptr), name(nullptr), arg(nullptr), namelen(0)
{
prev_ = tag(this);
next_ = tag(this);
}
/**
* @brief Creates a new Option that is a one-element linked list and has the given
* values for @ref desc, @ref name and @ref arg.
*
* If @c name_ points at a character other than '-' it will be assumed to refer to a
* short option and @ref namelen will be set to 1. Otherwise the length will extend to
* the first '=' character or the string's 0-terminator.
*/
Option(const Descriptor* desc_, const char* name_, const char* arg_)
{
init(desc_, name_, arg_);
}
/**
* @brief Makes @c *this a copy of @c orig except for the linked list pointers.
*
* After this operation @c *this will be a one-element linked list.
*/
void operator=(const Option& orig)
{
init(orig.desc, orig.name, orig.arg);
}
/**
* @brief Makes @c *this a copy of @c orig except for the linked list pointers.
*
* After this operation @c *this will be a one-element linked list.
*/
Option(const Option& orig)
{
init(orig.desc, orig.name, orig.arg);
}
private:
/**
* @internal
* @brief Sets the fields of this Option to the given values (extracting @c name if necessary).
*
* If @c name_ points at a character other than '-' it will be assumed to refer to a
* short option and @ref namelen will be set to 1. Otherwise the length will extend to
* the first '=' character or the string's 0-terminator.
*/
void init(const Descriptor* desc_, const char* name_, const char* arg_)
{
desc = desc_;
name = name_;
arg = arg_;
prev_ = tag(this);
next_ = tag(this);
namelen = 0;
if (name == nullptr)
return;
namelen = 1;
if (name[0] != '-')
return;
while (name[namelen] != 0 && name[namelen] != '=')
++namelen;
}
static Option* tag(Option* ptr)
{
return (Option*) ((unsigned long long) ptr | 1);
}
static Option* untag(Option* ptr)
{
return (Option*) ((unsigned long long) ptr & ~1ull);
}
static bool isTagged(Option* ptr)
{
return ((unsigned long long) ptr & 1);
}
};
/**
* @brief Functions for checking the validity of option arguments.
*
* @copydetails CheckArg
*
* The following example code
* can serve as starting place for writing your own more complex CheckArg functions:
* @code
* struct Arg: public option::Arg
* {
* static void printError(const char* msg1, const option::Option& opt, const char* msg2)
* {
* fprintf(stderr, "ERROR: %s", msg1);
* fwrite(opt.name, opt.namelen, 1, stderr);
* fprintf(stderr, "%s", msg2);
* }
*
* static option::ArgStatus Unknown(const option::Option& option, bool msg)
* {
* if (msg) printError("Unknown option '", option, "'\n");
* return option::ARG_ILLEGAL;
* }
*
* static option::ArgStatus Required(const option::Option& option, bool msg)
* {
* if (option.arg != 0)
* return option::ARG_OK;
*
* if (msg) printError("Option '", option, "' requires an argument\n");
* return option::ARG_ILLEGAL;
* }
*
* static option::ArgStatus NonEmpty(const option::Option& option, bool msg)
* {
* if (option.arg != 0 && option.arg[0] != 0)
* return option::ARG_OK;
*
* if (msg) printError("Option '", option, "' requires a non-empty argument\n");
* return option::ARG_ILLEGAL;
* }
*
* static option::ArgStatus Numeric(const option::Option& option, bool msg)
* {
* char* endptr = 0;
* if (option.arg != 0 && strtol(option.arg, &endptr, 10)){};
* if (endptr != option.arg && *endptr == 0)
* return option::ARG_OK;
*
* if (msg) printError("Option '", option, "' requires a numeric argument\n");
* return option::ARG_ILLEGAL;
* }
* };
* @endcode
*/
struct Arg
{
//! @brief For options that don't take an argument: Returns ARG_NONE.
static ArgStatus None(const Option&, bool)
{
return ARG_NONE;
}
//! @brief Returns ARG_OK if the argument is attached and ARG_IGNORE otherwise.
static ArgStatus Optional(const Option& option, bool)
{
if (option.arg && option.name[option.namelen] != 0)
return ARG_OK;
else
return ARG_IGNORE;
}
};
/**
* @brief Determines the minimum lengths of the buffer and options arrays used for Parser.
*
* Because Parser doesn't use dynamic memory its output arrays have to be pre-allocated.
* If you don't want to use fixed size arrays (which may turn out too small, causing
* command line arguments to be dropped), you can use Stats to determine the correct sizes.
* Stats work cumulative. You can first pass in your default options and then the real
* options and afterwards the counts will reflect the union.
*/
struct Stats
{
/**
* @brief Number of elements needed for a @c buffer[] array to be used for
* @ref Parser::parse() "parsing" the same argument vectors that were fed
* into this Stats object.
*
* @note
* This number is always 1 greater than the actual number needed, to give
* you a sentinel element.
*/
unsigned buffer_max;
/**
* @brief Number of elements needed for an @c options[] array to be used for
* @ref Parser::parse() "parsing" the same argument vectors that were fed
* into this Stats object.
*
* @li This number is always 1 greater than the actual number needed, to give
* you a sentinel element.
* @li This number depends only on the @c usage, not the argument vectors, because
* the @c options array needs exactly one slot for each possible Descriptor::index.
*/
unsigned options_max;
/**
* @brief Creates a Stats object with counts set to 1 (for the sentinel element).
*/
Stats() :
buffer_max(1), options_max(1) // 1 more than necessary as sentinel
{
}
/**
* @brief Creates a new Stats object and immediately updates it for the
* given @c usage and argument vector. You may pass 0 for @c argc and/or @c argv,
* if you just want to update @ref options_max.
*
* @note
* The calls to Stats methods must match the later calls to Parser methods.
* See Parser::parse() for the meaning of the arguments.
*/
Stats(bool gnu, const Descriptor usage[], int argc, const char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false) :
buffer_max(1), options_max(1) // 1 more than necessary as sentinel
{
add(gnu, usage, argc, argv, min_abbr_len, single_minus_longopt);
}
//! @brief Stats(...) with non-const argv.
Stats(bool gnu, const Descriptor usage[], int argc, char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false) :
buffer_max(1), options_max(1) // 1 more than necessary as sentinel
{
add(gnu, usage, argc, const_cast<const char**>(argv), min_abbr_len, single_minus_longopt);
}
//! @brief POSIX Stats(...) (gnu==false).
Stats(const Descriptor usage[], int argc, const char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false) :
buffer_max(1), options_max(1) // 1 more than necessary as sentinel
{
add(false, usage, argc, argv, min_abbr_len, single_minus_longopt);
}
//! @brief POSIX Stats(...) (gnu==false) with non-const argv.
Stats(const Descriptor usage[], int argc, char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false) :
buffer_max(1), options_max(1) // 1 more than necessary as sentinel
{
add(false, usage, argc, const_cast<const char**>(argv), min_abbr_len, single_minus_longopt);
}
/**
* @brief Updates this Stats object for the
* given @c usage and argument vector. You may pass 0 for @c argc and/or @c argv,
* if you just want to update @ref options_max.
*
* @note
* The calls to Stats methods must match the later calls to Parser methods.
* See Parser::parse() for the meaning of the arguments.
*/
void add(bool gnu, const Descriptor usage[], int argc, const char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false);
//! @brief add() with non-const argv.
void add(bool gnu, const Descriptor usage[], int argc, char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false)
{
add(gnu, usage, argc, const_cast<const char**>(argv), min_abbr_len, single_minus_longopt);
}
//! @brief POSIX add() (gnu==false).
void add(const Descriptor usage[], int argc, const char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false)
{
add(false, usage, argc, argv, min_abbr_len, single_minus_longopt);
}
//! @brief POSIX add() (gnu==false) with non-const argv.
void add(const Descriptor usage[], int argc, char** argv, int min_abbr_len = 0, //
bool single_minus_longopt = false)
{
add(false, usage, argc, const_cast<const char**>(argv), min_abbr_len, single_minus_longopt);
}
private:
class CountOptionsAction;
};
/**
* @brief Checks argument vectors for validity and parses them into data
* structures that are easier to work with.
*
* @par Example:
* @code
* int main(int argc, char* argv[])
* {
* argc-=(argc>0); argv+=(argc>0); // skip program name argv[0] if present
* option::Stats stats(usage, argc, argv);
* option::Option options[stats.options_max], buffer[stats.buffer_max];
* option::Parser parse(usage, argc, argv, options, buffer);
*
* if (parse.error())
* return 1;
*
* if (options[HELP])
* ...
* @endcode
*/
class Parser
{
int op_count; //!< @internal @brief see optionsCount()
int nonop_count; //!< @internal @brief see nonOptionsCount()
const char** nonop_args; //!< @internal @brief see nonOptions()
bool err; //!< @internal @brief see error()
public:
/**
* @brief Creates a new Parser.
*/
Parser() :
op_count(0), nonop_count(0), nonop_args(nullptr), err(false)
{
}
/**
* @brief Creates a new Parser and immediately parses the given argument vector.
* @copydetails parse()
*/
Parser(bool gnu, const Descriptor usage[], int argc, const char** argv, Option options[], Option buffer[],
int min_abbr_len = 0, bool single_minus_longopt = false, int bufmax = -1) :
op_count(0), nonop_count(0), nonop_args(nullptr), err(false)
{
parse(gnu, usage, argc, argv, options, buffer, min_abbr_len, single_minus_longopt, bufmax);
}
//! @brief Parser(...) with non-const argv.
Parser(bool gnu, const Descriptor usage[], int argc, char** argv, Option options[], Option buffer[],
int min_abbr_len = 0, bool single_minus_longopt = false, int bufmax = -1) :
op_count(0), nonop_count(0), nonop_args(nullptr), err(false)
{
parse(gnu, usage, argc, const_cast<const char**>(argv), options, buffer, min_abbr_len, single_minus_longopt, bufmax);
}
//! @brief POSIX Parser(...) (gnu==false).
Parser(const Descriptor usage[], int argc, const char** argv, Option options[], Option buffer[], int min_abbr_len = 0,
bool single_minus_longopt = false, int bufmax = -1) :
op_count(0), nonop_count(0), nonop_args(nullptr), err(false)
{
parse(false, usage, argc, argv, options, buffer, min_abbr_len, single_minus_longopt, bufmax);
}
//! @brief POSIX Parser(...) (gnu==false) with non-const argv.
Parser(const Descriptor usage[], int argc, char** argv, Option options[], Option buffer[], int min_abbr_len = 0,
bool single_minus_longopt = false, int bufmax = -1) :
op_count(0), nonop_count(0), nonop_args(nullptr), err(false)
{
parse(false, usage, argc, const_cast<const char**>(argv), options, buffer, min_abbr_len, single_minus_longopt, bufmax);
}
/**
* @brief Parses the given argument vector.
*
* @param gnu if true, parse() will not stop at the first non-option argument. Instead it will
* reorder arguments so that all non-options are at the end. This is the default behaviour
* of GNU getopt() but is not conforming to POSIX. @n
* Note, that once the argument vector has been reordered, the @c gnu flag will have
* no further effect on this argument vector. So it is enough to pass @c gnu==true when
* creating Stats.
* @param usage Array of Descriptor objects that describe the options to support. The last entry
* of this array must have 0 in all fields.
* @param argc The number of elements from @c argv that are to be parsed. If you pass -1, the number
* will be determined automatically. In that case the @c argv list must end with a NULL
* pointer.
* @param argv The arguments to be parsed. If you pass -1 as @c argc the last pointer in the @c argv
* list must be NULL to mark the end.
* @param options Each entry is the first element of a linked list of Options. Each new option
* that is parsed will be appended to the list specified by that Option's
* Descriptor::index. If an entry is not yet used (i.e. the Option is invalid),
* it will be replaced rather than appended to. @n
* The minimum length of this array is the greatest Descriptor::index value that
* occurs in @c usage @e PLUS ONE.
* @param buffer Each argument that is successfully parsed (including unknown arguments, if they
* have a Descriptor whose CheckArg does not return @ref ARG_ILLEGAL) will be stored in this
* array. parse() scans the array for the first invalid entry and begins writing at that
* index. You can pass @c bufmax to limit the number of options stored.
* @param min_abbr_len Passing a value <code> min_abbr_len > 0 </code> enables abbreviated long
* options. The parser will match a prefix of a long option as if it was
* the full long option (e.g. @c --foob=10 will be interpreted as if it was
* @c --foobar=10 ), as long as the prefix has at least @c min_abbr_len characters
* (not counting the @c -- ) and is unambiguous.
* @n Be careful if combining @c min_abbr_len=1 with @c single_minus_longopt=true
* because the ambiguity check does not consider short options and abbreviated
* single minus long options will take precedence over short options.
* @param single_minus_longopt Passing @c true for this option allows long options to begin with
* a single minus. The double minus form will still be recognized. Note that
* single minus long options take precedence over short options and short option
* groups. E.g. @c -file would be interpreted as @c --file and not as
* <code> -f -i -l -e </code> (assuming a long option named @c "file" exists).
* @param bufmax The greatest index in the @c buffer[] array that parse() will write to is
* @c bufmax-1. If there are more options, they will be processed (in particular
* their CheckArg will be called) but not stored. @n
* If you used Stats::buffer_max to dimension this array, you can pass
* -1 (or not pass @c bufmax at all) which tells parse() that the buffer is
* "large enough".
* @attention
* Remember that @c options and @c buffer store Option @e objects, not pointers. Therefore it
* is not possible for the same object to be in both arrays. For those options that are found in
* both @c buffer[] and @c options[] the respective objects are independent copies. And only the
* objects in @c options[] are properly linked via Option::next() and Option::prev().
* You can iterate over @c buffer[] to
* process all options in the order they appear in the argument vector, but if you want access to
* the other Options with the same Descriptor::index, then you @e must access the linked list via
* @c options[]. You can get the linked list in options from a buffer object via something like
* @c options[buffer[i].index()].
*/
void parse(bool gnu, const Descriptor usage[], int argc, const char** argv, Option options[], Option buffer[],
int min_abbr_len = 0, bool single_minus_longopt = false, int bufmax = -1);
//! @brief parse() with non-const argv.
void parse(bool gnu, const Descriptor usage[], int argc, char** argv, Option options[], Option buffer[],
int min_abbr_len = 0, bool single_minus_longopt = false, int bufmax = -1)
{
parse(gnu, usage, argc, const_cast<const char**>(argv), options, buffer, min_abbr_len, single_minus_longopt, bufmax);
}
//! @brief POSIX parse() (gnu==false).
void parse(const Descriptor usage[], int argc, const char** argv, Option options[], Option buffer[],
int min_abbr_len = 0, bool single_minus_longopt = false, int bufmax = -1)
{
parse(false, usage, argc, argv, options, buffer, min_abbr_len, single_minus_longopt, bufmax);
}
//! @brief POSIX parse() (gnu==false) with non-const argv.
void parse(const Descriptor usage[], int argc, char** argv, Option options[], Option buffer[], int min_abbr_len = 0,
bool single_minus_longopt = false, int bufmax = -1)
{
parse(false, usage, argc, const_cast<const char**>(argv), options, buffer, min_abbr_len, single_minus_longopt, bufmax);
}
/**
* @brief Returns the number of valid Option objects in @c buffer[].
*
* @li The returned value always reflects the number of Options in the buffer[] array used for
* the most recent call to parse().
* @li The count (and the buffer[]) includes unknown options if they are collected
* (see Descriptor::longopt).
*/
int optionsCount()
{
return op_count;
}
/**
* @brief Returns the number of non-option arguments that remained at the end of the
* most recent parse() that actually encountered non-option arguments.
*
* @note
* A parse() that does not encounter non-option arguments will leave this value
* as well as nonOptions() undisturbed. This means you can feed the Parser a
* default argument vector that contains non-option arguments (e.g. a default filename).
* Then you feed it the actual arguments from the user. If the user has supplied at
* least one non-option argument, all of the non-option arguments from the default
* disappear and are replaced by the user's non-option arguments. However, if the
* user does not supply any non-option arguments the defaults will still be in
* effect.
*/
int nonOptionsCount()
{
return nonop_count;
}
/**
* @brief Returns a pointer to an array of non-option arguments (only valid
* if <code>nonOptionsCount() >0 </code>).
*
* @li parse() does not copy arguments, so this pointer points into the actual argument
* vector as passed to parse().
* @li As explained at nonOptionsCount() this pointer is only changed by parse() calls
* that actually encounter non-option arguments. A parse() call that encounters only
* options, will not change nonOptions().
*/
const char** nonOptions()
{
return nonop_args;
}
/**
* @brief Returns <b><code>nonOptions()[i]</code></b> (@e without checking if i is in range!).
*/
const char* nonOption(int i)
{
return nonOptions()[i];
}
/**
* @brief Returns @c true if an unrecoverable error occurred while parsing options.
*
* An illegal argument to an option (i.e. CheckArg returns @ref ARG_ILLEGAL) is an
* unrecoverable error that aborts the parse. Unknown options are only an error if
* their CheckArg function returns @ref ARG_ILLEGAL. Otherwise they are collected.
* In that case if you want to exit the program if either an illegal argument
* or an unknown option has been passed, use code like this
*
* @code
* if (parser.error() || options[UNKNOWN])
* exit(1);
* @endcode
*
*/
bool error()
{
return err;
}
private:
friend struct Stats;
class StoreOptionAction;
struct Action;
/**
* @internal
* @brief This is the core function that does all the parsing.
* @retval false iff an unrecoverable error occurred.
*/
static bool workhorse(bool gnu, const Descriptor usage[], int numargs, const char** args, Action& action,
bool single_minus_longopt, bool print_errors, int min_abbr_len);
/**
* @internal
* @brief Returns true iff @c st1 is a prefix of @c st2 and
* in case @c st2 is longer than @c st1, then
* the first additional character is '='.
*
* @par Examples:
* @code
* streq("foo", "foo=bar") == true
* streq("foo", "foobar") == false
* streq("foo", "foo") == true
* streq("foo=bar", "foo") == false
* @endcode
*/
static bool streq(const char* st1, const char* st2)
{
while (*st1 != 0)
if (*st1++ != *st2++)
return false;
return (*st2 == 0 || *st2 == '=');
}
/**
* @internal
* @brief Like streq() but handles abbreviations.
*
* Returns true iff @c st1 and @c st2 have a common
* prefix with the following properties:
* @li (if min > 0) its length is at least @c min characters or the same length as @c st1 (whichever is smaller).
* @li (if min <= 0) its length is the same as that of @c st1
* @li within @c st2 the character following the common prefix is either '=' or end-of-string.
*
* Examples:
* @code
* streqabbr("foo", "foo=bar",<anything>) == true
* streqabbr("foo", "fo=bar" , 2) == true
* streqabbr("foo", "fo" , 2) == true
* streqabbr("foo", "fo" , 0) == false
* streqabbr("foo", "f=bar" , 2) == false
* streqabbr("foo", "f" , 2) == false
* streqabbr("fo" , "foo=bar",<anything>) == false
* streqabbr("foo", "foobar" ,<anything>) == false
* streqabbr("foo", "fobar" ,<anything>) == false
* streqabbr("foo", "foo" ,<anything>) == true
* @endcode
*/
static bool streqabbr(const char* st1, const char* st2, long long min)
{
const char* st1start = st1;
while (*st1 != 0 && (*st1 == *st2))
{
++st1;
++st2;
}
return (*st1 == 0 || (min > 0 && (st1 - st1start) >= min)) && (*st2 == 0 || *st2 == '=');
}
/**
* @internal
* @brief Returns true iff character @c ch is contained in the string @c st.
*
* Returns @c true for @c ch==0 .
*/
static bool instr(char ch, const char* st)
{
while (*st != 0 && *st != ch)
++st;
return *st == ch;
}
/**
* @internal
* @brief Rotates <code>args[-count],...,args[-1],args[0]</code> to become
* <code>args[0],args[-count],...,args[-1]</code>.
*/
static void shift(const char** args, int count)
{
for (int i = 0; i > -count; --i)
{
const char* temp = args[i];
args[i] = args[i - 1];
args[i - 1] = temp;
}
}
};
/**
* @internal
* @brief Interface for actions Parser::workhorse() should perform for each Option it
* parses.
*/
struct Parser::Action
{
virtual ~Action() {}
/**
* @brief Called by Parser::workhorse() for each Option that has been successfully
* parsed (including unknown
* options if they have a Descriptor whose Descriptor::check_arg does not return
* @ref ARG_ILLEGAL.
*
* Returns @c false iff a fatal error has occured and the parse should be aborted.
*/
virtual bool perform(Option&)
{
return true;
}
/**
* @brief Called by Parser::workhorse() after finishing the parse.
* @param numargs the number of non-option arguments remaining
* @param args pointer to the first remaining non-option argument (if numargs > 0).
*
* @return
* @c false iff a fatal error has occurred.
*/
virtual bool finished(int numargs, const char** args)
{
(void) numargs;
(void) args;
return true;
}
};
/**
* @internal
* @brief An Action to pass to Parser::workhorse() that will increment a counter for
* each parsed Option.
*/
class Stats::CountOptionsAction: public Parser::Action
{
unsigned* buffer_max;
public:
/**
* Creates a new CountOptionsAction that will increase @c *buffer_max_ for each
* parsed Option.
*/
CountOptionsAction(unsigned* buffer_max_) :
buffer_max(buffer_max_)
{
}
bool perform(Option&)
{
if (*buffer_max == 0x7fffffff)
return false; // overflow protection: don't accept number of options that doesn't fit signed int
++*buffer_max;
return true;
}
};
/**
* @internal
* @brief An Action to pass to Parser::workhorse() that will store each parsed Option in
* appropriate arrays (see Parser::parse()).
*/
class Parser::StoreOptionAction: public Parser::Action
{
Parser& parser;
Option* options;
Option* buffer;
int bufmax; //! Number of slots in @c buffer. @c -1 means "large enough".
public:
/**
* @brief Creates a new StoreOption action.
* @param parser_ the parser whose op_count should be updated.
* @param options_ each Option @c o is chained into the linked list @c options_[o.desc->index]
* @param buffer_ each Option is appended to this array as long as there's a free slot.
* @param bufmax_ number of slots in @c buffer_. @c -1 means "large enough".
*/
StoreOptionAction(Parser& parser_, Option options_[], Option buffer_[], int bufmax_) :
parser(parser_), options(options_), buffer(buffer_), bufmax(bufmax_)
{
// find first empty slot in buffer (if any)
int bufidx = 0;
while ((bufmax < 0 || bufidx < bufmax) && buffer[bufidx])
++bufidx;
// set parser's optionCount
parser.op_count = bufidx;
}
bool perform(Option& option)
{
if (bufmax < 0 || parser.op_count < bufmax)
{
if (parser.op_count == 0x7fffffff)
return false; // overflow protection: don't accept number of options that doesn't fit signed int
buffer[parser.op_count] = option;
int idx = buffer[parser.op_count].desc->index;
if (options[idx])
options[idx].append(buffer[parser.op_count]);
else
options[idx] = buffer[parser.op_count];
++parser.op_count;
}
return true; // NOTE: an option that is discarded because of a full buffer is not fatal
}
bool finished(int numargs, const char** args)
{
// only overwrite non-option argument list if there's at least 1
// new non-option argument. Otherwise we keep the old list. This
// makes it easy to use default non-option arguments.
if (numargs > 0)
{
parser.nonop_count = numargs;
parser.nonop_args = args;
}
return true;
}
};
inline void Parser::parse(bool gnu, const Descriptor usage[], int argc, const char** argv, Option options[],
Option buffer[], int min_abbr_len, bool single_minus_longopt, int bufmax)
{
StoreOptionAction action(*this, options, buffer, bufmax);
err = !workhorse(gnu, usage, argc, argv, action, single_minus_longopt, true, min_abbr_len);
}
inline void Stats::add(bool gnu, const Descriptor usage[], int argc, const char** argv, int min_abbr_len,
bool single_minus_longopt)
{
// determine size of options array. This is the greatest index used in the usage + 1
int i = 0;
while (usage[i].shortopt != nullptr)
{
if (usage[i].index + 1 >= options_max)
options_max = (usage[i].index + 1) + 1; // 1 more than necessary as sentinel
++i;
}
CountOptionsAction action(&buffer_max);
Parser::workhorse(gnu, usage, argc, argv, action, single_minus_longopt, false, min_abbr_len);
}
inline bool Parser::workhorse(bool gnu, const Descriptor usage[], int numargs, const char** args, Action& action,
bool single_minus_longopt, bool print_errors, int min_abbr_len)
{
// protect against NULL pointer
if (args == nullptr)
numargs = 0;
int nonops = 0;
while (numargs != 0 && *args != nullptr)
{
const char* param = *args; // param can be --long-option, -srto or non-option argument
// in POSIX mode the first non-option argument terminates the option list
// a lone minus character is a non-option argument
if (param[0] != '-' || param[1] == 0)
{
if (gnu)
{
++nonops;
++args;
if (numargs > 0)
--numargs;
continue;
}
else
break;
}
// -- terminates the option list. The -- itself is skipped.
if (param[1] == '-' && param[2] == 0)
{
shift(args, nonops);
++args;
if (numargs > 0)
--numargs;
break;
}
bool handle_short_options;
const char* longopt_name;
if (param[1] == '-') // if --long-option
{
handle_short_options = false;
longopt_name = param + 2;
}
else
{
handle_short_options = true;
longopt_name = param + 1; //for testing a potential -long-option
}
bool try_single_minus_longopt = single_minus_longopt;
bool have_more_args = (numargs > 1 || numargs < 0); // is referencing argv[1] valid?
do // loop over short options in group, for long options the body is executed only once
{
int idx = 0;
const char* optarg = nullptr;
/******************** long option **********************/
if (handle_short_options == false || try_single_minus_longopt)
{
idx = 0;
while (usage[idx].longopt != nullptr && !streq(usage[idx].longopt, longopt_name))
++idx;
if (usage[idx].longopt == nullptr && min_abbr_len > 0) // if we should try to match abbreviated long options
{
int i1 = 0;
while (usage[i1].longopt != nullptr && !streqabbr(usage[i1].longopt, longopt_name, min_abbr_len))
++i1;
if (usage[i1].longopt != nullptr)
{ // now test if the match is unambiguous by checking for another match
int i2 = i1 + 1;
while (usage[i2].longopt != nullptr && !streqabbr(usage[i2].longopt, longopt_name, min_abbr_len))
++i2;
if (usage[i2].longopt == nullptr) // if there was no second match it's unambiguous, so accept i1 as idx
idx = i1;
}
}
// if we found something, disable handle_short_options (only relevant if single_minus_longopt)
if (usage[idx].longopt != nullptr)
handle_short_options = false;
try_single_minus_longopt = false; // prevent looking for longopt in the middle of shortopt group
optarg = longopt_name;
while (*optarg != 0 && *optarg != '=')
++optarg;
if (*optarg == '=') // attached argument
++optarg;
else
// possibly detached argument
optarg = (have_more_args ? args[1] : nullptr);
}
/************************ short option ***********************************/
if (handle_short_options)
{
if (*++param == 0) // point at the 1st/next option character
break; // end of short option group
idx = 0;
while (usage[idx].shortopt != nullptr && !instr(*param, usage[idx].shortopt))
++idx;
if (param[1] == 0) // if the potential argument is separate
optarg = (have_more_args ? args[1] : nullptr);
else
// if the potential argument is attached
optarg = param + 1;
}
const Descriptor* descriptor = &usage[idx];
if (descriptor->shortopt == nullptr) /************** unknown option ********************/
{
// look for dummy entry (shortopt == "" and longopt == "") to use as Descriptor for unknown options
idx = 0;
while (usage[idx].shortopt != nullptr && (usage[idx].shortopt[0] != 0 || usage[idx].longopt[0] != 0))
++idx;
descriptor = (usage[idx].shortopt == nullptr ? nullptr : &usage[idx]);
}
if (descriptor != nullptr)
{
Option option(descriptor, param, optarg);
switch (descriptor->check_arg(option, print_errors))
{
case ARG_ILLEGAL:
return false; // fatal
case ARG_OK:
// skip one element of the argument vector, if it's a separated argument
if (optarg != nullptr && have_more_args && optarg == args[1])
{
shift(args, nonops);
if (numargs > 0)
--numargs;
++args;
}
// No further short options are possible after an argument
handle_short_options = false;
break;
case ARG_IGNORE:
case ARG_NONE:
option.arg = nullptr;
break;
}
if (!action.perform(option))
return false;
}
} while (handle_short_options);
shift(args, nonops);
++args;
if (numargs > 0)
--numargs;
} // while
if (numargs > 0 && *args == nullptr) // It's a bug in the caller if numargs is greater than the actual number
numargs = 0; // of arguments, but as a service to the user we fix this if we spot it.
if (numargs < 0) // if we don't know the number of remaining non-option arguments
{ // we need to count them
numargs = 0;
while (args[numargs] != nullptr)
++numargs;
}
return action.finished(numargs + nonops, args - nonops);
}
/**
* @internal
* @brief The implementation of option::printUsage().
*/
struct PrintUsageImplementation
{
/**
* @internal
* @brief Interface for Functors that write (part of) a string somewhere.
*/
struct IStringWriter
{
virtual ~IStringWriter() {}
/**
* @brief Writes the given number of chars beginning at the given pointer somewhere.
*/
virtual void operator()(const char*, int)
{
}
};
/**
* @internal
* @brief Encapsulates a function with signature <code>func(string, size)</code> where
* string can be initialized with a const char* and size with an int.
*/
template<typename Function>
struct FunctionWriter: public IStringWriter
{
Function* write;
virtual void operator()(const char* str, int size)
{
(*write)(str, size);
}
FunctionWriter(Function* w) :
write(w)
{
}
};
/**
* @internal
* @brief Encapsulates a reference to an object with a <code>write(string, size)</code>
* method like that of @c std::ostream.
*/
template<typename OStream>
struct OStreamWriter: public IStringWriter
{
OStream& ostream;
virtual void operator()(const char* str, int size)
{
ostream.write(str, size);
}
OStreamWriter(OStream& o) :
ostream(o)
{
}
};
/**
* @internal
* @brief Like OStreamWriter but encapsulates a @c const reference, which is
* typically a temporary object of a user class.
*/
template<typename Temporary>
struct TemporaryWriter: public IStringWriter
{
const Temporary& userstream;
virtual void operator()(const char* str, int size)
{
userstream.write(str, size);
}
TemporaryWriter(const Temporary& u) :
userstream(u)
{
}
};
/**
* @internal
* @brief Encapsulates a function with the signature <code>func(fd, string, size)</code> (the
* signature of the @c write() system call)
* where fd can be initialized from an int, string from a const char* and size from an int.
*/
template<typename Syscall>
struct SyscallWriter: public IStringWriter
{
Syscall* write;
int fd;
virtual void operator()(const char* str, int size)
{
(*write)(fd, str, size);
}
SyscallWriter(Syscall* w, int f) :
write(w), fd(f)
{
}
};
/**
* @internal
* @brief Encapsulates a function with the same signature as @c std::fwrite().
*/
template<typename Function, typename Stream>
struct StreamWriter: public IStringWriter
{
Function* fwrite;
Stream* stream;
virtual void operator()(const char* str, int size)
{
(*fwrite)(str, size, 1, stream);
}
StreamWriter(Function* w, Stream* s) :
fwrite(w), stream(s)
{
}
};
/**
* @internal
* @brief Sets <code> i1 = max(i1, i2) </code>
*/
static void upmax(int& i1, int i2)
{
i1 = (i1 >= i2 ? i1 : i2);
}
/**
* @internal
* @brief Moves the "cursor" to column @c want_x assuming it is currently at column @c x
* and sets @c x=want_x .
* If <code> x > want_x </code>, a line break is output before indenting.
*
* @param write Spaces and possibly a line break are written via this functor to get
* the desired indentation @c want_x .
* @param[in,out] x the current indentation. Set to @c want_x by this method.
* @param want_x the desired indentation.
*/
static void indent(IStringWriter& write, int& x, int want_x)
{
int indent = want_x - x;
if (indent < 0)
{
write("\n", 1);
indent = want_x;
}
if (indent > 0)
{
char space = ' ';
for (int i = 0; i < indent; ++i)
write(&space, 1);
x = want_x;
}
}
/**
* @brief Returns true if ch is the unicode code point of a wide character.
*
* @note
* The following character ranges are treated as wide
* @code
* 1100..115F
* 2329..232A (just 2 characters!)
* 2E80..A4C6 except for 303F
* A960..A97C
* AC00..D7FB
* F900..FAFF
* FE10..FE6B
* FF01..FF60
* FFE0..FFE6
* 1B000......
* @endcode
*/
static bool isWideChar(unsigned ch)
{
if (ch == 0x303F)
return false;
return ((0x1100 <= ch && ch <= 0x115F) || (0x2329 <= ch && ch <= 0x232A) || (0x2E80 <= ch && ch <= 0xA4C6)
|| (0xA960 <= ch && ch <= 0xA97C) || (0xAC00 <= ch && ch <= 0xD7FB) || (0xF900 <= ch && ch <= 0xFAFF)
|| (0xFE10 <= ch && ch <= 0xFE6B) || (0xFF01 <= ch && ch <= 0xFF60) || (0xFFE0 <= ch && ch <= 0xFFE6)
|| (0x1B000 <= ch));
}
/**
* @internal
* @brief Splits a @c Descriptor[] array into tables, rows, lines and columns and
* iterates over these components.
*
* The top-level organizational unit is the @e table.
* A table begins at a Descriptor with @c help!=NULL and extends up to
* a Descriptor with @c help==NULL.
*
* A table consists of @e rows. Due to line-wrapping and explicit breaks
* a row may take multiple lines on screen. Rows within the table are separated
* by \\n. They never cross Descriptor boundaries. This means a row ends either
* at \\n or the 0 at the end of the help string.
*
* A row consists of columns/cells. Columns/cells within a row are separated by \\t.
* Line breaks within a cell are marked by \\v.
*
* Rows in the same table need not have the same number of columns/cells. The
* extreme case are interjections, which are rows that contain neither \\t nor \\v.
* These are NOT treated specially by LinePartIterator, but they are treated
* specially by printUsage().
*
* LinePartIterator iterates through the usage at 3 levels: table, row and part.
* Tables and rows are as described above. A @e part is a line within a cell.
* LinePartIterator iterates through 1st parts of all cells, then through the 2nd
* parts of all cells (if any),... @n
* Example: The row <code> "1 \v 3 \t 2 \v 4" </code> has 2 cells/columns and 4 parts.
* The parts will be returned in the order 1, 2, 3, 4.
*
* It is possible that some cells have fewer parts than others. In this case
* LinePartIterator will "fill up" these cells with 0-length parts. IOW, LinePartIterator
* always returns the same number of parts for each column. Note that this is different
* from the way rows and columns are handled. LinePartIterator does @e not guarantee that
* the same number of columns will be returned for each row.
*
*/
class LinePartIterator
{
const Descriptor* tablestart; //!< The 1st descriptor of the current table.
const Descriptor* rowdesc; //!< The Descriptor that contains the current row.
const char* rowstart; //!< Ptr to 1st character of current row within rowdesc->help.
const char* ptr; //!< Ptr to current part within the current row.
int col; //!< Index of current column.
int len; //!< Length of the current part (that ptr points at) in BYTES
int screenlen; //!< Length of the current part in screen columns (taking narrow/wide chars into account).
int max_line_in_block; //!< Greatest index of a line within the block. This is the number of \\v within the cell with the most \\vs.
int line_in_block; //!< Line index within the current cell of the current part.
int target_line_in_block; //!< Line index of the parts we should return to the user on this iteration.
bool hit_target_line; //!< Flag whether we encountered a part with line index target_line_in_block in the current cell.
/**
* @brief Determines the byte and character lengths of the part at @ref ptr and
* stores them in @ref len and @ref screenlen respectively.
*/
void update_length()
{
screenlen = 0;
for (len = 0; ptr[len] != 0 && ptr[len] != '\v' && ptr[len] != '\t' && ptr[len] != '\n'; ++len)
{
++screenlen;
unsigned ch = (unsigned char) ptr[len];
if (ch > 0xC1) // everything <= 0xC1 (yes, even 0xC1 itself) is not a valid UTF-8 start byte
{
// int __builtin_clz (unsigned int x)
// Returns the number of leading 0-bits in x, starting at the most significant bit
unsigned mask = (unsigned) -1 >> __builtin_clz(ch ^ 0xff);
ch = ch & mask; // mask out length bits, we don't verify their correctness
while (((unsigned char) ptr[len + 1] ^ 0x80) <= 0x3F) // while next byte is continuation byte
{
ch = (ch << 6) ^ (unsigned char) ptr[len + 1] ^ 0x80; // add continuation to char code
++len;
}
// ch is the decoded unicode code point
if (ch >= 0x1100 && isWideChar(ch)) // the test for 0x1100 is here to avoid the function call in the Latin case
++screenlen;
}
}
}
public:
//! @brief Creates an iterator for @c usage.
LinePartIterator(const Descriptor usage[]) :
tablestart(usage), rowdesc(nullptr), rowstart(nullptr), ptr(nullptr), col(-1), len(0), max_line_in_block(0), line_in_block(0),
target_line_in_block(0), hit_target_line(true)
{
}
/**
* @brief Moves iteration to the next table (if any). Has to be called once on a new
* LinePartIterator to move to the 1st table.
* @retval false if moving to next table failed because no further table exists.
*/
bool nextTable()
{
// If this is NOT the first time nextTable() is called after the constructor,
// then skip to the next table break (i.e. a Descriptor with help == 0)
if (rowdesc != nullptr)
{
while (tablestart->help != nullptr && tablestart->shortopt != nullptr)
++tablestart;
}
// Find the next table after the break (if any)
while (tablestart->help == nullptr && tablestart->shortopt != nullptr)
++tablestart;
restartTable();
return rowstart != nullptr;
}
/**
* @brief Reset iteration to the beginning of the current table.
*/
void restartTable()
{
rowdesc = tablestart;
rowstart = tablestart->help;
ptr = nullptr;
}
/**
* @brief Moves iteration to the next row (if any). Has to be called once after each call to
* @ref nextTable() to move to the 1st row of the table.
* @retval false if moving to next row failed because no further row exists.
*/
bool nextRow()
{
if (ptr == nullptr)
{
restartRow();
return rowstart != nullptr;
}
while (*ptr != 0 && *ptr != '\n')
++ptr;
if (*ptr == 0)
{
if ((rowdesc + 1)->help == nullptr) // table break
return false;
++rowdesc;
rowstart = rowdesc->help;
}
else // if (*ptr == '\n')
{
rowstart = ptr + 1;
}
restartRow();
return true;
}
/**
* @brief Reset iteration to the beginning of the current row.
*/
void restartRow()
{
ptr = rowstart;
col = -1;
len = 0;
screenlen = 0;
max_line_in_block = 0;
line_in_block = 0;
target_line_in_block = 0;
hit_target_line = true;
}
/**
* @brief Moves iteration to the next part (if any). Has to be called once after each call to
* @ref nextRow() to move to the 1st part of the row.
* @retval false if moving to next part failed because no further part exists.
*
* See @ref LinePartIterator for details about the iteration.
*/
bool next()
{
if (ptr == nullptr)
return false;
if (col == -1)
{
col = 0;
update_length();
return true;
}
ptr += len;
while (true)
{
switch (*ptr)
{
case '\v':
upmax(max_line_in_block, ++line_in_block);
++ptr;
break;
case '\t':
if (!hit_target_line) // if previous column did not have the targetline
{ // then "insert" a 0-length part
update_length();
hit_target_line = true;
return true;
}
hit_target_line = false;
line_in_block = 0;
++col;
++ptr;
break;
case 0:
case '\n':
if (!hit_target_line) // if previous column did not have the targetline
{ // then "insert" a 0-length part
update_length();
hit_target_line = true;
return true;
}
if (++target_line_in_block > max_line_in_block)
{
update_length();
return false;
}
hit_target_line = false;
line_in_block = 0;
col = 0;
ptr = rowstart;
continue;
default:
++ptr;
continue;
} // switch
if (line_in_block == target_line_in_block)
{
update_length();
hit_target_line = true;
return true;
}
} // while
}
/**
* @brief Returns the index (counting from 0) of the column in which
* the part pointed to by @ref data() is located.
*/
int column()
{
return col;
}
/**
* @brief Returns the index (counting from 0) of the line within the current column
* this part belongs to.
*/
int line()
{
return target_line_in_block; // NOT line_in_block !!! It would be wrong if !hit_target_line
}
/**
* @brief Returns the length of the part pointed to by @ref data() in raw chars (not UTF-8 characters).
*/
int length()
{
return len;
}
/**
* @brief Returns the width in screen columns of the part pointed to by @ref data().
* Takes multi-byte UTF-8 sequences and wide characters into account.
*/
int screenLength()
{
return screenlen;
}
/**
* @brief Returns the current part of the iteration.
*/
const char* data()
{
return ptr;
}
};
/**
* @internal
* @brief Takes input and line wraps it, writing out one line at a time so that
* it can be interleaved with output from other columns.
*
* The LineWrapper is used to handle the last column of each table as well as interjections.
* The LineWrapper is called once for each line of output. If the data given to it fits
* into the designated width of the last column it is simply written out. If there
* is too much data, an appropriate split point is located and only the data up to this
* split point is written out. The rest of the data is queued for the next line.
* That way the last column can be line wrapped and interleaved with data from
* other columns. The following example makes this clearer:
* @code
* Column 1,1 Column 2,1 This is a long text
* Column 1,2 Column 2,2 that does not fit into
* a single line.
* @endcode
*
* The difficulty in producing this output is that the whole string
* "This is a long text that does not fit into a single line" is the
* 1st and only part of column 3. In order to produce the above
* output the string must be output piecemeal, interleaved with
* the data from the other columns.
*/
class LineWrapper
{
static const int bufmask = 15; //!< Must be a power of 2 minus 1.
/**
* @brief Ring buffer for length component of pair (data, length).
*/
int lenbuf[bufmask + 1];
/**
* @brief Ring buffer for data component of pair (data, length).
*/
const char* datbuf[bufmask + 1];
/**
* @brief The indentation of the column to which the LineBuffer outputs. LineBuffer
* assumes that the indentation has already been written when @ref process()
* is called, so this value is only used when a buffer flush requires writing
* additional lines of output.
*/
int x;
/**
* @brief The width of the column to line wrap.
*/
int width;
int head; //!< @brief index for next write
int tail; //!< @brief index for next read - 1 (i.e. increment tail BEFORE read)
/**
* @brief Multiple methods of LineWrapper may decide to flush part of the buffer to
* free up space. The contract of process() says that only 1 line is output. So
* this variable is used to track whether something has output a line. It is
* reset at the beginning of process() and checked at the end to decide if
* output has already occurred or is still needed.
*/
bool wrote_something;
bool buf_empty()
{
return ((tail + 1) & bufmask) == head;
}
bool buf_full()
{
return tail == head;
}
void buf_store(const char* data, int len)
{
lenbuf[head] = len;
datbuf[head] = data;
head = (head + 1) & bufmask;
}
//! @brief Call BEFORE reading ...buf[tail].
void buf_next()
{
tail = (tail + 1) & bufmask;
}
/**
* @brief Writes (data,len) into the ring buffer. If the buffer is full, a single line
* is flushed out of the buffer into @c write.
*/
void output(IStringWriter& write, const char* data, int len)
{
if (buf_full())
write_one_line(write);
buf_store(data, len);
}
/**
* @brief Writes a single line of output from the buffer to @c write.
*/
void write_one_line(IStringWriter& write)
{
if (wrote_something) // if we already wrote something, we need to start a new line
{
write("\n", 1);
int _ = 0;
indent(write, _, x);
}
if (!buf_empty())
{
buf_next();
write(datbuf[tail], lenbuf[tail]);
}
wrote_something = true;
}
public:
/**
* @brief Writes out all remaining data from the LineWrapper using @c write.
* Unlike @ref process() this method indents all lines including the first and
* will output a \\n at the end (but only if something has been written).
*/
void flush(IStringWriter& write)
{
if (buf_empty())
return;
int _ = 0;
indent(write, _, x);
wrote_something = false;
while (!buf_empty())
write_one_line(write);
write("\n", 1);
}
/**
* @brief Process, wrap and output the next piece of data.
*
* process() will output at least one line of output. This is not necessarily
* the @c data passed in. It may be data queued from a prior call to process().
* If the internal buffer is full, more than 1 line will be output.
*
* process() assumes that the a proper amount of indentation has already been
* output. It won't write any further indentation before the 1st line. If
* more than 1 line is written due to buffer constraints, the lines following
* the first will be indented by this method, though.
*
* No \\n is written by this method after the last line that is written.
*
* @param write where to write the data.
* @param data the new chunk of data to write.
* @param len the length of the chunk of data to write.
*/
void process(IStringWriter& write, const char* data, int len)
{
wrote_something = false;
while (len > 0)
{
if (len <= width) // quick test that works because utf8width <= len (all wide chars have at least 2 bytes)
{
output(write, data, len);
len = 0;
}
else // if (len > width) it's possible (but not guaranteed) that utf8len > width
{
int utf8width = 0;
int maxi = 0;
while (maxi < len && utf8width < width)
{
int charbytes = 1;
unsigned ch = (unsigned char) data[maxi];
if (ch > 0xC1) // everything <= 0xC1 (yes, even 0xC1 itself) is not a valid UTF-8 start byte
{
// int __builtin_clz (unsigned int x)
// Returns the number of leading 0-bits in x, starting at the most significant bit
unsigned mask = (unsigned) -1 >> __builtin_clz(ch ^ 0xff);
ch = ch & mask; // mask out length bits, we don't verify their correctness
while ((maxi + charbytes < len) && //
(((unsigned char) data[maxi + charbytes] ^ 0x80) <= 0x3F)) // while next byte is continuation byte
{
ch = (ch << 6) ^ (unsigned char) data[maxi + charbytes] ^ 0x80; // add continuation to char code
++charbytes;
}
// ch is the decoded unicode code point
if (ch >= 0x1100 && isWideChar(ch)) // the test for 0x1100 is here to avoid the function call in the Latin case
{
if (utf8width + 2 > width)
break;
++utf8width;
}
}
++utf8width;
maxi += charbytes;
}
// data[maxi-1] is the last byte of the UTF-8 sequence of the last character that fits
// onto the 1st line. If maxi == len, all characters fit on the line.
if (maxi == len)
{
output(write, data, len);
len = 0;
}
else // if (maxi < len) at least 1 character (data[maxi] that is) doesn't fit on the line
{
int i;
for (i = maxi; i >= 0; --i)
if (data[i] == ' ')
break;
if (i >= 0)
{
output(write, data, i);
data += i + 1;
len -= i + 1;
}
else // did not find a space to split at => split before data[maxi]
{ // data[maxi] is always the beginning of a character, never a continuation byte
output(write, data, maxi);
data += maxi;
len -= maxi;
}
}
}
}
if (!wrote_something) // if we didn't already write something to make space in the buffer
write_one_line(write); // write at most one line of actual output
}
/**
* @brief Constructs a LineWrapper that wraps its output to fit into
* screen columns @c x1 (incl.) to @c x2 (excl.).
*
* @c x1 gives the indentation LineWrapper uses if it needs to indent.
*/
LineWrapper(int x1, int x2) :
x(x1), width(x2 - x1), head(0), tail(bufmask)
{
if (width < 2) // because of wide characters we need at least width 2 or the code breaks
width = 2;
}
};
/**
* @internal
* @brief This is the implementation that is shared between all printUsage() templates.
* Because all printUsage() templates share this implementation, there is no template bloat.
*/
static void printUsage(IStringWriter& write, const Descriptor usage[], int width = 80, //
int last_column_min_percent = 50, int last_column_own_line_max_percent = 75)
{
if (width < 1) // protect against nonsense values
width = 80;
if (width > 10000) // protect against overflow in the following computation
width = 10000;
int last_column_min_width = ((width * last_column_min_percent) + 50) / 100;
int last_column_own_line_max_width = ((width * last_column_own_line_max_percent) + 50) / 100;
if (last_column_own_line_max_width == 0)
last_column_own_line_max_width = 1;
LinePartIterator part(usage);
while (part.nextTable())
{
/***************** Determine column widths *******************************/
const int maxcolumns = 8; // 8 columns are enough for everyone
int col_width[maxcolumns];
int lastcolumn;
int leftwidth;
int overlong_column_threshold = 10000;
do
{
lastcolumn = 0;
for (int i = 0; i < maxcolumns; ++i)
col_width[i] = 0;
part.restartTable();
while (part.nextRow())
{
while (part.next())
{
if (part.column() < maxcolumns)
{
upmax(lastcolumn, part.column());
if (part.screenLength() < overlong_column_threshold)
// We don't let rows that don't use table separators (\t or \v) influence
// the width of column 0. This allows the user to interject section headers
// or explanatory paragraphs that do not participate in the table layout.
if (part.column() > 0 || part.line() > 0 || part.data()[part.length()] == '\t'
|| part.data()[part.length()] == '\v')
upmax(col_width[part.column()], part.screenLength());
}
}
}
/*
* If the last column doesn't fit on the same
* line as the other columns, we can fix that by starting it on its own line.
* However we can't do this for any of the columns 0..lastcolumn-1.
* If their sum exceeds the maximum width we try to fix this by iteratively
* ignoring the widest line parts in the width determination until
* we arrive at a series of column widths that fit into one line.
* The result is a layout where everything is nicely formatted
* except for a few overlong fragments.
* */
leftwidth = 0;
overlong_column_threshold = 0;
for (int i = 0; i < lastcolumn; ++i)
{
leftwidth += col_width[i];
upmax(overlong_column_threshold, col_width[i]);
}
} while (leftwidth > width);
/**************** Determine tab stops and last column handling **********************/
int tabstop[maxcolumns];
tabstop[0] = 0;
for (int i = 1; i < maxcolumns; ++i)
tabstop[i] = tabstop[i - 1] + col_width[i - 1];
int rightwidth = width - tabstop[lastcolumn];
bool print_last_column_on_own_line = false;
if (rightwidth < last_column_min_width && // if we don't have the minimum requested width for the last column
( col_width[lastcolumn] == 0 || // and all last columns are > overlong_column_threshold
rightwidth < col_width[lastcolumn] // or there is at least one last column that requires more than the space available
)
)
{
print_last_column_on_own_line = true;
rightwidth = last_column_own_line_max_width;
}
// If lastcolumn == 0 we must disable print_last_column_on_own_line because
// otherwise 2 copies of the last (and only) column would be output.
// Actually this is just defensive programming. It is currently not
// possible that lastcolumn==0 and print_last_column_on_own_line==true
// at the same time, because lastcolumn==0 => tabstop[lastcolumn] == 0 =>
// rightwidth==width => rightwidth>=last_column_min_width (unless someone passes
// a bullshit value >100 for last_column_min_percent) => the above if condition
// is false => print_last_column_on_own_line==false
if (lastcolumn == 0)
print_last_column_on_own_line = false;
LineWrapper lastColumnLineWrapper(width - rightwidth, width);
LineWrapper interjectionLineWrapper(0, width);
part.restartTable();
/***************** Print out all rows of the table *************************************/
while (part.nextRow())
{
int x = -1;
while (part.next())
{
if (part.column() > lastcolumn)
continue; // drop excess columns (can happen if lastcolumn == maxcolumns-1)
if (part.column() == 0)
{
if (x >= 0)
write("\n", 1);
x = 0;
}
indent(write, x, tabstop[part.column()]);
if ((part.column() < lastcolumn)
&& (part.column() > 0 || part.line() > 0 || part.data()[part.length()] == '\t'
|| part.data()[part.length()] == '\v'))
{
write(part.data(), part.length());
x += part.screenLength();
}
else // either part.column() == lastcolumn or we are in the special case of
// an interjection that doesn't contain \v or \t
{
// NOTE: This code block is not necessarily executed for
// each line, because some rows may have fewer columns.
LineWrapper& lineWrapper = (part.column() == 0) ? interjectionLineWrapper : lastColumnLineWrapper;
if (!print_last_column_on_own_line || part.column() != lastcolumn)
lineWrapper.process(write, part.data(), part.length());
}
} // while
if (print_last_column_on_own_line)
{
part.restartRow();
while (part.next())
{
if (part.column() == lastcolumn)
{
write("\n", 1);
int _ = 0;
indent(write, _, width - rightwidth);
lastColumnLineWrapper.process(write, part.data(), part.length());
}
}
}
write("\n", 1);
lastColumnLineWrapper.flush(write);
interjectionLineWrapper.flush(write);
}
}
}
}
;
/**
* @brief Outputs a nicely formatted usage string with support for multi-column formatting
* and line-wrapping.
*
* printUsage() takes the @c help texts of a Descriptor[] array and formats them into
* a usage message, wrapping lines to achieve the desired output width.
*
* <b>Table formatting:</b>
*
* Aside from plain strings which are simply line-wrapped, the usage may contain tables. Tables
* are used to align elements in the output.
*
* @code
* // Without a table. The explanatory texts are not aligned.
* -c, --create |Creates something.
* -k, --kill |Destroys something.
*
* // With table formatting. The explanatory texts are aligned.
* -c, --create |Creates something.
* -k, --kill |Destroys something.
* @endcode
*
* Table formatting removes the need to pad help texts manually with spaces to achieve
* alignment. To create a table, simply insert \\t (tab) characters to separate the cells
* within a row.
*
* @code
* const option::Descriptor usage[] = {
* {..., "-c, --create \tCreates something." },
* {..., "-k, --kill \tDestroys something." }, ...
* @endcode
*
* Note that you must include the minimum amount of space desired between cells yourself.
* Table formatting will insert further spaces as needed to achieve alignment.
*
* You can insert line breaks within cells by using \\v (vertical tab).
*
* @code
* const option::Descriptor usage[] = {
* {..., "-c,\v--create \tCreates\vsomething." },
* {..., "-k,\v--kill \tDestroys\vsomething." }, ...
*
* // results in
*
* -c, Creates
* --create something.
* -k, Destroys
* --kill something.
* @endcode
*
* You can mix lines that do not use \\t or \\v with those that do. The plain
* lines will not mess up the table layout. Alignment of the table columns will
* be maintained even across these interjections.
*
* @code
* const option::Descriptor usage[] = {
* {..., "-c, --create \tCreates something." },
* {..., "----------------------------------" },
* {..., "-k, --kill \tDestroys something." }, ...
*
* // results in
*
* -c, --create Creates something.
* ----------------------------------
* -k, --kill Destroys something.
* @endcode
*
* You can have multiple tables within the same usage whose columns are
* aligned independently. Simply insert a dummy Descriptor with @c help==0.
*
* @code
* const option::Descriptor usage[] = {
* {..., "Long options:" },
* {..., "--very-long-option \tDoes something long." },
* {..., "--ultra-super-mega-long-option \tTakes forever to complete." },
* {..., 0 }, // ---------- table break -----------
* {..., "Short options:" },
* {..., "-s \tShort." },
* {..., "-q \tQuick." }, ...
*
* // results in
*
* Long options:
* --very-long-option Does something long.
* --ultra-super-mega-long-option Takes forever to complete.
* Short options:
* -s Short.
* -q Quick.
*
* // Without the table break it would be
*
* Long options:
* --very-long-option Does something long.
* --ultra-super-mega-long-option Takes forever to complete.
* Short options:
* -s Short.
* -q Quick.
* @endcode
*
* <b>Output methods:</b>
*
* Because TheLeanMeanC++Option parser is freestanding, you have to provide the means for
* output in the first argument(s) to printUsage(). Because printUsage() is implemented as
* a set of template functions, you have great flexibility in your choice of output
* method. The following example demonstrates typical uses. Anything that's similar enough
* will work.
*
* @code
* #include <unistd.h> // write()
* #include <iostream> // cout
* #include <sstream> // ostringstream
* #include <cstdio> // fwrite()
* using namespace std;
*
* void my_write(const char* str, int size) {
* fwrite(str, size, 1, stdout);
* }
*
* struct MyWriter {
* void write(const char* buf, size_t size) const {
* fwrite(str, size, 1, stdout);
* }
* };
*
* struct MyWriteFunctor {
* void operator()(const char* buf, size_t size) {
* fwrite(str, size, 1, stdout);
* }
* };
* ...
* printUsage(my_write, usage); // custom write function
* printUsage(MyWriter(), usage); // temporary of a custom class
* MyWriter writer;
* printUsage(writer, usage); // custom class object
* MyWriteFunctor wfunctor;
* printUsage(&wfunctor, usage); // custom functor
* printUsage(write, 1, usage); // write() to file descriptor 1
* printUsage(cout, usage); // an ostream&
* printUsage(fwrite, stdout, usage); // fwrite() to stdout
* ostringstream sstr;
* printUsage(sstr, usage); // an ostringstream&
*
* @endcode
*
* @par Notes:
* @li the @c write() method of a class that is to be passed as a temporary
* as @c MyWriter() is in the example, must be a @c const method, because
* temporary objects are passed as const reference. This only applies to
* temporary objects that are created and destroyed in the same statement.
* If you create an object like @c writer in the example, this restriction
* does not apply.
* @li a functor like @c MyWriteFunctor in the example must be passed as a pointer.
* This differs from the way functors are passed to e.g. the STL algorithms.
* @li All printUsage() templates are tiny wrappers around a shared non-template implementation.
* So there's no penalty for using different versions in the same program.
* @li printUsage() always interprets Descriptor::help as UTF-8 and always produces UTF-8-encoded
* output. If your system uses a different charset, you must do your own conversion. You
* may also need to change the font of the console to see non-ASCII characters properly.
* This is particularly true for Windows.
* @li @b Security @b warning: Do not insert untrusted strings (such as user-supplied arguments)
* into the usage. printUsage() has no protection against malicious UTF-8 sequences.
*
* @param prn The output method to use. See the examples above.
* @param usage the Descriptor[] array whose @c help texts will be formatted.
* @param width the maximum number of characters per output line. Note that this number is
* in actual characters, not bytes. printUsage() supports UTF-8 in @c help and will
* count multi-byte UTF-8 sequences properly. Asian wide characters are counted
* as 2 characters.
* @param last_column_min_percent (0-100) The minimum percentage of @c width that should be available
* for the last column (which typically contains the textual explanation of an option).
* If less space is available, the last column will be printed on its own line, indented
* according to @c last_column_own_line_max_percent.
* @param last_column_own_line_max_percent (0-100) If the last column is printed on its own line due to
* less than @c last_column_min_percent of the width being available, then only
* @c last_column_own_line_max_percent of the extra line(s) will be used for the
* last column's text. This ensures an indentation. See example below.
*
* @code
* // width=20, last_column_min_percent=50 (i.e. last col. min. width=10)
* --3456789 1234567890
* 1234567890
*
* // width=20, last_column_min_percent=75 (i.e. last col. min. width=15)
* // last_column_own_line_max_percent=75
* --3456789
* 123456789012345
* 67890
*
* // width=20, last_column_min_percent=75 (i.e. last col. min. width=15)
* // last_column_own_line_max_percent=33 (i.e. max. 5)
* --3456789
* 12345
* 67890
* 12345
* 67890
* @endcode
*/
template<typename OStream>
void printUsage(OStream& prn, const Descriptor usage[], int width = 80, int last_column_min_percent = 50,
int last_column_own_line_max_percent = 75)
{
PrintUsageImplementation::OStreamWriter<OStream> write(prn);
PrintUsageImplementation::printUsage(write, usage, width, last_column_min_percent, last_column_own_line_max_percent);
}
template<typename Function>
void printUsage(Function* prn, const Descriptor usage[], int width = 80, int last_column_min_percent = 50,
int last_column_own_line_max_percent = 75)
{
PrintUsageImplementation::FunctionWriter<Function> write(prn);
PrintUsageImplementation::printUsage(write, usage, width, last_column_min_percent, last_column_own_line_max_percent);
}
template<typename Temporary>
void printUsage(const Temporary& prn, const Descriptor usage[], int width = 80, int last_column_min_percent = 50,
int last_column_own_line_max_percent = 75)
{
PrintUsageImplementation::TemporaryWriter<Temporary> write(prn);
PrintUsageImplementation::printUsage(write, usage, width, last_column_min_percent, last_column_own_line_max_percent);
}
template<typename Syscall>
void printUsage(Syscall* prn, int fd, const Descriptor usage[], int width = 80, int last_column_min_percent = 50,
int last_column_own_line_max_percent = 75)
{
PrintUsageImplementation::SyscallWriter<Syscall> write(prn, fd);
PrintUsageImplementation::printUsage(write, usage, width, last_column_min_percent, last_column_own_line_max_percent);
}
template<typename Function, typename Stream>
void printUsage(Function* prn, Stream* stream, const Descriptor usage[], int width = 80, int last_column_min_percent =
50,
int last_column_own_line_max_percent = 75)
{
PrintUsageImplementation::StreamWriter<Function, Stream> write(prn, stream);
PrintUsageImplementation::printUsage(write, usage, width, last_column_min_percent, last_column_own_line_max_percent);
}
}
// namespace option
#endif /* OPTIONPARSER_H_ */
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