poafloc

Parser Of Arguments For Lines Of Commands
git clone git://git.dimitrijedobrota.com/poafloc.git
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commit130362e87a569b184f3dfef590569354de92397a
parentaee752599f659cfc997c7b10dd8f54fc63c30eed
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateMon, 10 Jun 2024 19:35:47 +0200

Switch to CMake and restructure the project

Diffstat:
M.gitignore|++--------
ACMakeLists.txt|++++++++++++++++
DMakefile|-----------
Dargs.hpp|---------------------------------------------------------------------------------
Ddemo.cpp|---------------------------------------------------------------------------------
Ademo/CMakeLists.txt|+++++++++++++
Ademo/main.cpp|+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ainclude/args.hpp|+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Asrc/CMakeLists.txt|+++++++++++++
Asrc/args.cpp|+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Asrc/help.cpp|+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Asrc/trie.cpp|++++++++++++++++++++++++++++++++++++++

12 files changed, 647 insertions(+), 596 deletions(-)

diff --git a/.gitignore b/.gitignore

@@ -1,8 +1,2 @@

*
!Makefile
!args.hpp
!demo.cpp
!.clang-format
!.gitignore
build
.cache

diff --git a/CMakeLists.txt b/CMakeLists.txt

@@ -0,0 +1,16 @@

cmake_minimum_required(VERSION 3.25.2)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
project(
args
VERSION 0.0.1
DESCRIPTION "Command Line Argument Parser"
LANGUAGES CXX
)
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
add_subdirectory(src)
add_subdirectory(demo)

diff --git a/Makefile b/Makefile

@@ -1,11 +0,0 @@

all: demo
demo: demo.cpp args.hpp
g++ -o $@ $< -std=c++20 -Wall -Werror -ggdb
clean:
rm -rf demo
.PHONY: clean

diff --git a/args.hpp b/args.hpp

@@ -1,493 +0,0 @@

#ifndef ARGS_HPP
#define ARGS_HPP
#include <algorithm>
#include <cstdint>
#include <cstring>
#include <exception>
#include <format>
#include <iostream>
#include <sstream>
#include <unordered_map>
#include <vector>
class Parser {
public:
struct option_t {
const char *name;
const int key;
const char *arg;
const uint8_t flags;
const char *message;
const int group;
};
enum Option {
ARG_OPTIONAL = 0x1,
HIDDEN = 0x2,
ALIAS = 0x4,
};
enum Key {
ARG = 0,
END = 0x1000001,
NO_ARGS = 0x1000002,
INIT = 0x1000003,
SUCCESS = 0x1000004,
ERROR = 0x1000005,
};
struct argp_t {
using parse_f = int (*)(int key, const char *arg, Parser *parser);
const option_t *options;
const parse_f parse;
const char *doc;
const char *message;
};
static int parse(argp_t *argp, int argc, char *argv[], void *input) {
Parser parser(input, argp);
return parser.parse(argc, argv, &parser);
}
void *input;
private:
Parser(void *input, argp_t *argp) : input(input), argp(argp) {
int group = 0, key_last = 0;
bool hidden = false;
for (int i = 0; true; i++) {
const auto &opt = argp->options[i];
if (!opt.name && !opt.key && !opt.message) break;
if (!opt.name && !opt.key) {
group = opt.group ? opt.group : group + 1;
help_entries.emplace_back(nullptr, opt.message, group);
continue;
}
if (!opt.key) {
if ((opt.flags & ALIAS) == 0) {
std::cerr << "non alias without a key\n";
throw new std::runtime_error("no key");
}
if (!key_last) {
std::cerr << "no option to alias\n";
throw new std::runtime_error("no alias");
}
trie.insert(opt.name, key_last);
if (hidden) continue;
if (opt.flags & Option::HIDDEN) continue;
help_entries.back().push(opt.name);
} else {
if (options.count(opt.key)) {
std::cerr << std::format("duplicate key {}\n", opt.key);
throw new std::runtime_error("duplicate key");
}
if (opt.name) trie.insert(opt.name, opt.key);
options[key_last = opt.key] = &opt;
bool arg_opt = opt.flags & Option::ARG_OPTIONAL;
if ((opt.flags & ALIAS) == 0) {
if ((hidden = opt.flags & Option::HIDDEN)) continue;
help_entries.emplace_back(opt.arg, opt.message, group,
arg_opt);
if (opt.name) help_entries.back().push(opt.name);
if (std::isprint(opt.key)) {
help_entries.back().push(opt.key);
}
} else {
if (!key_last) {
std::cerr << "no option to alias\n";
throw new std::runtime_error("no alias");
}
if (hidden) continue;
if (opt.flags & Option::HIDDEN) continue;
if (opt.name) help_entries.back().push(opt.name);
if (std::isprint(opt.key)) {
help_entries.back().push(opt.key);
}
}
}
}
help_entries.emplace_back(nullptr, "Give this help list", -1);
help_entries.back().push("help");
help_entries.back().push('?');
help_entries.emplace_back(nullptr, "Give a short usage message", -1);
help_entries.back().push("usage");
std::sort(begin(help_entries), end(help_entries));
}
int parse(int argc, char *argv[], void *input) {
int args = 0, i;
argp->parse(Key::INIT, 0, this);
for (i = 1; i < argc; i++) {
if (argv[i][0] != '-') {
argp->parse(Key::ARG, argv[i], this);
args++;
continue;
}
// stop parsing options, rest are normal arguments
if (!std::strcmp(argv[i], "--")) break;
if (argv[i][1] != '-') { // short option
const char *opt = argv[i] + 1;
// loop over ganged options
for (int j = 0; opt[j]; j++) {
const char key = opt[j];
if (key == '?') help(argv[0]);
if (!options.count(key)) goto unknown;
const auto *option = options[key];
const char *arg = nullptr;
if (option->arg) {
if (opt[j + 1] != 0) {
// rest of the line is option argument
arg = opt + j + 1;
} else if ((option->flags & ARG_OPTIONAL) == 0) {
// next argv is option argument
if (i == argc) goto missing;
arg = argv[++i];
}
}
argp->parse(key, arg, this);
// if last option required argument we are done
if (arg) break;
}
} else { // long option
const char *opt = argv[i] + 2;
const auto eq = std::strchr(opt, '=');
std::string opt_s = !eq ? opt : std::string(opt, eq - opt);
if (opt_s == "help") {
if (eq) goto excess;
help(argv[0]);
}
if (opt_s == "usage") {
if (eq) goto excess;
usage(argv[0]);
}
const int key = trie.get(opt_s);
if (!key) goto unknown;
const auto *option = options[key];
const char *arg = nullptr;
if (!option->arg && eq) goto excess;
if (option->arg) {
if (eq) {
// everything after = is option argument
arg = eq + 1;
} else if ((option->flags & ARG_OPTIONAL) == 0) {
// next argv is option argument
if (i == argc) goto missing;
arg = argv[++i];
}
}
argp->parse(key, arg, this);
}
}
// parse rest argv as normal arguments
for (i = i + 1; i < argc; i++) {
argp->parse(Key::ARG, argv[i], this);
args++;
}
if (!args) argp->parse(Key::NO_ARGS, 0, this);
argp->parse(Key::END, 0, this);
argp->parse(Key::SUCCESS, 0, this);
return 0;
unknown:
std::cerr << std::format("unknown option {}\n", argv[i]);
argp->parse(Key::ERROR, 0, this);
return 1;
missing:
std::cerr << std::format("option {} missing a value\n", argv[i]);
argp->parse(Key::ERROR, 0, this);
return 2;
excess:
std::cerr << std::format("option {} don't require a value\n", argv[i]);
argp->parse(Key::ERROR, 0, this);
return 3;
}
struct help_entry_t {
std::vector<const char *> opt_long;
std::vector<char> opt_short;
const char *arg;
const char *message;
int group;
bool opt;
help_entry_t(const char *arg, const char *message, int group,
bool opt = false)
: arg(arg), message(message), group(group), opt(opt) {}
void push(char sh) { opt_short.push_back(sh); }
void push(const char *lg) { opt_long.push_back(lg); }
bool operator<(const help_entry_t &rhs) const {
if (group != rhs.group) {
if (group && rhs.group) {
if (group < 0 && rhs.group < 0) return group < rhs.group;
if (group < 0 || rhs.group < 0) return rhs.group < 0;
return group < rhs.group;
}
return !group;
}
const char l1 = !opt_long.empty() ? opt_long.front()[0]
: !opt_short.empty() ? opt_short.front()
: '0';
const char l2 = !rhs.opt_long.empty() ? rhs.opt_long.front()[0]
: !rhs.opt_short.empty() ? rhs.opt_short.front()
: '0';
if (l1 != l2) return l1 < l2;
return std::strcmp(opt_long.front(), rhs.opt_long.front()) < 0;
}
};
void print_usage(const char *name) const {
if (argp->doc) {
std::istringstream iss(argp->doc);
std::string s;
std::getline(iss, s, '\n');
std::cout << " " << s;
while (std::getline(iss, s, '\n')) {
std::cout << std::format("\n or: {} [OPTIONS...] {}", name,
s);
}
}
}
void help(const char *name) const {
std::string m1, m2;
if (argp->message) {
std::istringstream iss(argp->message);
std::getline(iss, m1, '\v');
std::getline(iss, m2, '\v');
}
std::cout << std::format("Usage: {} [OPTIONS...]", name);
print_usage(name);
if (!m1.empty()) std::cout << "\n" << m1;
std::cout << "\n\n";
bool first = true;
for (const auto &entry : help_entries) {
bool prev = false;
if (entry.opt_short.empty() && entry.opt_long.empty()) {
if (!first) std::cout << "\n";
if (entry.message) std::cout << " " << entry.message << ":\n";
continue;
}
first = false;
std::string message = " ";
for (const char c : entry.opt_short) {
if (!prev) prev = true;
else message += ", ";
message += std::format("-{}", c);
if (!entry.arg || !entry.opt_long.empty()) continue;
if (entry.opt) message += std::format("[{}]", entry.arg);
else message += std::format(" {}", entry.arg);
}
if (!prev) message += " ";
for (const auto l : entry.opt_long) {
if (!prev) prev = true;
else message += ", ";
message += std::format("--{}", l);
if (!entry.arg) continue;
if (entry.opt) message += std::format("[={}]", entry.arg);
else message += std::format("={}", entry.arg);
}
static const std::size_t limit = 30;
if (size(message) < limit) {
message += std::string(limit - size(message), ' ');
}
std::cout << message;
if (entry.message) {
std::istringstream iss(entry.message);
std::size_t count = 0;
std::string s;
std::cout << " ";
while (iss >> s) {
count += size(s);
if (count > limit) {
std::cout << std::endl << std::string(limit + 5, ' ');
count = size(s);
}
std::cout << s << " ";
}
}
std::cout << std::endl;
}
if (!m2.empty()) std::cout << "\n" << m2 << "\n";
exit(0);
}
void usage(const char *name) const {
static const std::size_t limit = 60;
static std::size_t count = 0;
static const auto print = [](const std::string &message) {
if (count + size(message) > limit) {
std::cout << "\n ";
count = 6;
}
std::cout << message;
count += size(message);
};
std::string message = std::format("Usage: {}", name);
message += " [-";
for (const auto &entry : help_entries) {
if (entry.arg) continue;
for (const char c : entry.opt_short) {
message += c;
}
}
message += "]";
std::cout << message;
count = size(message);
for (const auto &entry : help_entries) {
if (!entry.arg) continue;
for (const char c : entry.opt_short) {
if (entry.opt) print(std::format(" [-{}[{}]]", c, entry.arg));
else print(std::format(" [-{} {}]", c, entry.arg));
}
}
for (const auto &entry : help_entries) {
for (const char *name : entry.opt_long) {
if (!entry.arg) {
print(std::format(" [--{}]", name));
continue;
}
if (entry.opt) {
print(std::format(" [--{}[={}]]", name, entry.arg));
} else {
print(std::format(" [--{}={}]", name, entry.arg));
}
}
}
print_usage(name);
std::cout << std::endl;
exit(0);
}
class trie_t {
public:
~trie_t() noexcept {
for (uint8_t i = 0; i < 26; i++) {
delete children[i];
}
}
void insert(const std::string &option, int key) {
trie_t *crnt = this;
for (const char c : option) {
if (!crnt->terminal) crnt->key = key;
crnt->count++;
const uint8_t idx = c - 'a';
if (!crnt->children[idx]) crnt->children[idx] = new trie_t();
crnt = crnt->children[idx];
}
crnt->terminal = true;
crnt->key = key;
}
int get(const std::string &option) const {
const trie_t *crnt = this;
for (const char c : option) {
const uint8_t idx = c - 'a';
if (!crnt->children[idx]) return 0;
crnt = crnt->children[idx];
}
if (!crnt->terminal && crnt->count > 1) return 0;
return crnt->key;
}
private:
trie_t *children[26] = {0};
uint8_t count = 0;
int key = 0;
bool terminal = false;
};
const argp_t *argp;
std::unordered_map<int, const option_t *> options;
std::vector<help_entry_t> help_entries;
trie_t trie;
};
#endif

diff --git a/demo.cpp b/demo.cpp

@@ -1,84 +0,0 @@

#include "args.hpp"
#include <cstdint>
#include <vector>
void error(const std::string &message) { std::cerr << message << std::endl; }
struct arguments_t {
const char *output_file = "";
const char *input_file = "";
bool debug = 0;
bool hex = 0;
bool relocatable = 0;
std::vector<const char *> args;
};
int parse_opt(int key, const char *arg, Parser *parser) {
auto arguments = (arguments_t *)parser->input;
switch (key) {
case 777: arguments->debug = true; break;
case 'h':
if (arguments->relocatable) error("cannot mix -hex and -relocatable");
arguments->hex = true;
break;
case 'r':
if (arguments->hex) error("cannot mix -hex and -relocatable");
arguments->relocatable = true;
break;
case 'o': arguments->output_file = arg ? arg : "stdout"; break;
case 'i': arguments->input_file = arg; break;
case Parser::Key::ARG: arguments->args.push_back(arg); break;
case Parser::Key::ERROR: std::cerr << "handled error\n";
}
return 0;
}
using enum Parser::Option;
// clang-format off
static const Parser::option_t options[] = {
{ 0, 'R', 0, 0, "random 0-group option"},
{ 0, 0, 0, 0, "Program mode", 1},
{"relocatable", 'r', 0, 0, "Output in relocatable format"},
{ "hex", 'h', 0, 0, "Output in hex format"},
{"hexadecimal", 0, 0, ALIAS | HIDDEN},
{ 0, 0, 0, 0, "For developers", 4},
{ "debug", 777, 0, 0, "Enable debugging mode"},
{ 0, 0, 0, 0, "Input/output", 3},
{ "output", 'o', "file", ARG_OPTIONAL, "Output file, default stdout"},
{ 0, 'i', "file", 0, "Input file"},
{ 0, 0, 0, 0, "Informational Options", -1},
{0},
};
// clang-format on
int main(int argc, char *argv[]) {
arguments_t arguments;
Parser::argp_t argp = {
options, parse_opt, "doc string\nother usage",
"First half of the message\vsecond half of the message"};
if (Parser::parse(&argp, argc, argv, &arguments)) {
error("There was an error while parsing arguments");
return 1;
}
std::cout << "Command line options: " << std::endl;
std::cout << "\t input: " << arguments.input_file << std::endl;
std::cout << "\t output: " << arguments.output_file << std::endl;
std::cout << "\t hex: " << arguments.hex << std::endl;
std::cout << "\t debug: " << arguments.debug << std::endl;
std::cout << "\t relocatable: " << arguments.relocatable << std::endl;
std::cout << "\t args: ";
for (const auto &arg : arguments.args)
std::cout << arg << " ";
std::cout << std::endl;
return 0;
}

diff --git a/demo/CMakeLists.txt b/demo/CMakeLists.txt

@@ -0,0 +1,13 @@

set(GENERATE_OUT "${CMAKE_BINARY_DIR}/bin")
add_executable(demo
main.cpp
)
target_link_libraries(demo PRIVATE args)
set_target_properties(demo PROPERTIES
VERSION ${PROJECT_VERSION}
SOVERSION ${PROJECT_VERSION_MAJOR}
RUNTIME_OUTPUT_DIRECTORY "${GENERATE_OUT}"
)

diff --git a/demo/main.cpp b/demo/main.cpp

@@ -0,0 +1,85 @@

#include "args.hpp"
#include <cstdint>
#include <iostream>
#include <vector>
void error(const std::string &message) { std::cerr << message << std::endl; }
struct arguments_t {
const char *output_file = "";
const char *input_file = "";
bool debug = 0;
bool hex = 0;
bool relocatable = 0;
std::vector<const char *> args;
};
int parse_opt(int key, const char *arg, Parser *parser) {
auto arguments = (arguments_t *)parser->input;
switch (key) {
case 777: arguments->debug = true; break;
case 'h':
if (arguments->relocatable) error("cannot mix -hex and -relocatable");
arguments->hex = true;
break;
case 'r':
if (arguments->hex) error("cannot mix -hex and -relocatable");
arguments->relocatable = true;
break;
case 'o': arguments->output_file = arg ? arg : "stdout"; break;
case 'i': arguments->input_file = arg; break;
case Parser::Key::ARG: arguments->args.push_back(arg); break;
case Parser::Key::ERROR: std::cerr << "handled error\n";
}
return 0;
}
using enum Parser::Option;
// clang-format off
static const Parser::option_t options[] = {
{ 0, 'R', 0, 0, "random 0-group option"},
{ 0, 0, 0, 0, "Program mode", 1},
{"relocatable", 'r', 0, 0, "Output in relocatable format"},
{ "hex", 'h', 0, 0, "Output in hex format"},
{"hexadecimal", 0, 0, ALIAS | HIDDEN},
{ 0, 0, 0, 0, "For developers", 4},
{ "debug", 777, 0, 0, "Enable debugging mode"},
{ 0, 0, 0, 0, "Input/output", 3},
{ "output", 'o', "file", ARG_OPTIONAL, "Output file, default stdout"},
{ 0, 'i', "file", 0, "Input file"},
{ 0, 0, 0, 0, "Informational Options", -1},
{0},
};
// clang-format on
int main(int argc, char *argv[]) {
arguments_t arguments;
Parser::argp_t argp = {
options, parse_opt, "doc string\nother usage",
"First half of the message\vsecond half of the message"};
if (Parser::parse(&argp, argc, argv, &arguments)) {
error("There was an error while parsing arguments");
return 1;
}
std::cout << "Command line options: " << std::endl;
std::cout << "\t input: " << arguments.input_file << std::endl;
std::cout << "\t output: " << arguments.output_file << std::endl;
std::cout << "\t hex: " << arguments.hex << std::endl;
std::cout << "\t debug: " << arguments.debug << std::endl;
std::cout << "\t relocatable: " << arguments.relocatable << std::endl;
std::cout << "\t args: ";
for (const auto &arg : arguments.args)
std::cout << arg << " ";
std::cout << std::endl;
return 0;
}

diff --git a/include/args.hpp b/include/args.hpp

@@ -0,0 +1,99 @@

#ifndef ARGS_HPP
#define ARGS_HPP
#include <string>
#include <unordered_map>
#include <vector>
class Parser {
public:
struct option_t {
const char *name;
const int key;
const char *arg;
const int flags;
const char *message;
const int group;
};
enum Option {
ARG_OPTIONAL = 0x1,
HIDDEN = 0x2,
ALIAS = 0x4,
};
enum Key {
ARG = 0,
END = 0x1000001,
NO_ARGS = 0x1000002,
INIT = 0x1000003,
SUCCESS = 0x1000004,
ERROR = 0x1000005,
};
struct argp_t {
using parse_f = int (*)(int key, const char *arg, Parser *parser);
const option_t *options;
const parse_f parse;
const char *doc;
const char *message;
};
static int parse(argp_t *argp, int argc, char *argv[], void *input) {
Parser parser(input, argp);
return parser.parse(argc, argv, &parser);
}
void *input;
private:
Parser(void *input, argp_t *argp);
int parse(int argc, char *argv[], void *input);
void print_usage(const char *name) const;
void help(const char *name) const;
void usage(const char *name) const;
struct help_entry_t {
help_entry_t(const char *arg, const char *message, int group,
bool opt = false)
: arg(arg), message(message), group(group), opt(opt) {}
void push(char sh) { opt_short.push_back(sh); }
void push(const char *lg) { opt_long.push_back(lg); }
bool operator<(const help_entry_t &rhs) const;
const char *arg;
const char *message;
int group;
bool opt;
std::vector<const char *> opt_long;
std::vector<char> opt_short;
};
class trie_t {
public:
~trie_t() noexcept;
void insert(const std::string &option, int key);
int get(const std::string &option) const;
private:
trie_t *children[26] = {0};
int count = 0;
int key = 0;
bool terminal = false;
};
const argp_t *argp;
std::unordered_map<int, const option_t *> options;
std::vector<help_entry_t> help_entries;
trie_t trie;
};
#endif

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt

@@ -0,0 +1,13 @@

add_library(args args.cpp help.cpp trie.cpp)
target_include_directories(args PUBLIC ../include)
set_target_properties(args PROPERTIES
VERSION ${PROJECT_VERSION}
SOVERSION ${PROJECT_VERSION_MAJOR}
PUBLIC_HEADER ../include/args.hpp
)
install(TARGETS args
LIBRARY DESTINATION lib
PUBLIC_HEADER DESTINATION include
)

diff --git a/src/args.cpp b/src/args.cpp

@@ -0,0 +1,199 @@

#include "args.hpp"
#include <algorithm>
#include <cstring>
#include <exception>
#include <format>
#include <iostream>
#include <sstream>
Parser::Parser(void *input, argp_t *argp) : input(input), argp(argp) {
int group = 0, key_last = 0;
bool hidden = false;
for (int i = 0; true; i++) {
const auto &opt = argp->options[i];
if (!opt.name && !opt.key && !opt.message) break;
if (!opt.name && !opt.key) {
group = opt.group ? opt.group : group + 1;
help_entries.emplace_back(nullptr, opt.message, group);
continue;
}
if (!opt.key) {
if ((opt.flags & ALIAS) == 0) {
std::cerr << "non alias without a key\n";
throw new std::runtime_error("no key");
}
if (!key_last) {
std::cerr << "no option to alias\n";
throw new std::runtime_error("no alias");
}
trie.insert(opt.name, key_last);
if (hidden) continue;
if (opt.flags & Option::HIDDEN) continue;
help_entries.back().push(opt.name);
} else {
if (options.count(opt.key)) {
std::cerr << std::format("duplicate key {}\n", opt.key);
throw new std::runtime_error("duplicate key");
}
if (opt.name) trie.insert(opt.name, opt.key);
options[key_last = opt.key] = &opt;
bool arg_opt = opt.flags & Option::ARG_OPTIONAL;
if ((opt.flags & ALIAS) == 0) {
if ((hidden = opt.flags & Option::HIDDEN)) continue;
help_entries.emplace_back(opt.arg, opt.message, group,
arg_opt);
if (opt.name) help_entries.back().push(opt.name);
if (std::isprint(opt.key)) {
help_entries.back().push(opt.key);
}
} else {
if (!key_last) {
std::cerr << "no option to alias\n";
throw new std::runtime_error("no alias");
}
if (hidden) continue;
if (opt.flags & Option::HIDDEN) continue;
if (opt.name) help_entries.back().push(opt.name);
if (std::isprint(opt.key)) {
help_entries.back().push(opt.key);
}
}
}
}
help_entries.emplace_back(nullptr, "Give this help list", -1);
help_entries.back().push("help");
help_entries.back().push('?');
help_entries.emplace_back(nullptr, "Give a short usage message", -1);
help_entries.back().push("usage");
std::sort(begin(help_entries), end(help_entries));
}
int Parser::parse(int argc, char *argv[], void *input) {
int args = 0, i;
argp->parse(Key::INIT, 0, this);
for (i = 1; i < argc; i++) {
if (argv[i][0] != '-') {
argp->parse(Key::ARG, argv[i], this);
args++;
continue;
}
// stop parsing options, rest are normal arguments
if (!std::strcmp(argv[i], "--")) break;
if (argv[i][1] != '-') { // short option
const char *opt = argv[i] + 1;
// loop over ganged options
for (int j = 0; opt[j]; j++) {
const char key = opt[j];
if (key == '?') help(argv[0]);
if (!options.count(key)) goto unknown;
const auto *option = options[key];
const char *arg = nullptr;
if (option->arg) {
if (opt[j + 1] != 0) {
// rest of the line is option argument
arg = opt + j + 1;
} else if ((option->flags & ARG_OPTIONAL) == 0) {
// next argv is option argument
if (i == argc) goto missing;
arg = argv[++i];
}
}
argp->parse(key, arg, this);
// if last option required argument we are done
if (arg) break;
}
} else { // long option
const char *opt = argv[i] + 2;
const auto eq = std::strchr(opt, '=');
std::string opt_s = !eq ? opt : std::string(opt, eq - opt);
if (opt_s == "help") {
if (eq) goto excess;
help(argv[0]);
}
if (opt_s == "usage") {
if (eq) goto excess;
usage(argv[0]);
}
const int key = trie.get(opt_s);
if (!key) goto unknown;
const auto *option = options[key];
const char *arg = nullptr;
if (!option->arg && eq) goto excess;
if (option->arg) {
if (eq) {
// everything after = is option argument
arg = eq + 1;
} else if ((option->flags & ARG_OPTIONAL) == 0) {
// next argv is option argument
if (i == argc) goto missing;
arg = argv[++i];
}
}
argp->parse(key, arg, this);
}
}
// parse rest argv as normal arguments
for (i = i + 1; i < argc; i++) {
argp->parse(Key::ARG, argv[i], this);
args++;
}
if (!args) argp->parse(Key::NO_ARGS, 0, this);
argp->parse(Key::END, 0, this);
argp->parse(Key::SUCCESS, 0, this);
return 0;
unknown:
std::cerr << std::format("unknown option {}\n", argv[i]);
argp->parse(Key::ERROR, 0, this);
return 1;
missing:
std::cerr << std::format("option {} missing a value\n", argv[i]);
argp->parse(Key::ERROR, 0, this);
return 2;
excess:
std::cerr << std::format("option {} don't require a value\n", argv[i]);
argp->parse(Key::ERROR, 0, this);
return 3;
}

diff --git a/src/help.cpp b/src/help.cpp

@@ -0,0 +1,182 @@

#include "args.hpp"
#include <cstring>
#include <format>
#include <iostream>
#include <sstream>
bool Parser::help_entry_t::operator<(const help_entry_t &rhs) const {
if (group != rhs.group) {
if (group && rhs.group) {
if (group < 0 && rhs.group < 0) return group < rhs.group;
if (group < 0 || rhs.group < 0) return rhs.group < 0;
return group < rhs.group;
}
return !group;
}
const char l1 = !opt_long.empty() ? opt_long.front()[0]
: !opt_short.empty() ? opt_short.front()
: '0';
const char l2 = !rhs.opt_long.empty() ? rhs.opt_long.front()[0]
: !rhs.opt_short.empty() ? rhs.opt_short.front()
: '0';
if (l1 != l2) return l1 < l2;
return std::strcmp(opt_long.front(), rhs.opt_long.front()) < 0;
}
void Parser::print_usage(const char *name) const {
if (argp->doc) {
std::istringstream iss(argp->doc);
std::string s;
std::getline(iss, s, '\n');
std::cout << " " << s;
while (std::getline(iss, s, '\n')) {
std::cout << std::format("\n or: {} [OPTIONS...] {}", name, s);
}
}
}
void Parser::help(const char *name) const {
std::string m1, m2;
if (argp->message) {
std::istringstream iss(argp->message);
std::getline(iss, m1, '\v');
std::getline(iss, m2, '\v');
}
std::cout << std::format("Usage: {} [OPTIONS...]", name);
print_usage(name);
if (!m1.empty()) std::cout << "\n" << m1;
std::cout << "\n\n";
bool first = true;
for (const auto &entry : help_entries) {
bool prev = false;
if (entry.opt_short.empty() && entry.opt_long.empty()) {
if (!first) std::cout << "\n";
if (entry.message) std::cout << " " << entry.message << ":\n";
continue;
}
first = false;
std::string message = " ";
for (const char c : entry.opt_short) {
if (!prev) prev = true;
else message += ", ";
message += std::format("-{}", c);
if (!entry.arg || !entry.opt_long.empty()) continue;
if (entry.opt) message += std::format("[{}]", entry.arg);
else message += std::format(" {}", entry.arg);
}
if (!prev) message += " ";
for (const auto l : entry.opt_long) {
if (!prev) prev = true;
else message += ", ";
message += std::format("--{}", l);
if (!entry.arg) continue;
if (entry.opt) message += std::format("[={}]", entry.arg);
else message += std::format("={}", entry.arg);
}
static const std::size_t limit = 30;
if (size(message) < limit) {
message += std::string(limit - size(message), ' ');
}
std::cout << message;
if (entry.message) {
std::istringstream iss(entry.message);
std::size_t count = 0;
std::string s;
std::cout << " ";
while (iss >> s) {
count += size(s);
if (count > limit) {
std::cout << std::endl << std::string(limit + 5, ' ');
count = size(s);
}
std::cout << s << " ";
}
}
std::cout << std::endl;
}
if (!m2.empty()) std::cout << "\n" << m2 << "\n";
exit(0);
}
void Parser::usage(const char *name) const {
static const std::size_t limit = 60;
static std::size_t count = 0;
static const auto print = [](const std::string &message) {
if (count + size(message) > limit) {
std::cout << "\n ";
count = 6;
}
std::cout << message;
count += size(message);
};
std::string message = std::format("Usage: {}", name);
message += " [-";
for (const auto &entry : help_entries) {
if (entry.arg) continue;
for (const char c : entry.opt_short) {
message += c;
}
}
message += "]";
std::cout << message;
count = size(message);
for (const auto &entry : help_entries) {
if (!entry.arg) continue;
for (const char c : entry.opt_short) {
if (entry.opt) print(std::format(" [-{}[{}]]", c, entry.arg));
else print(std::format(" [-{} {}]", c, entry.arg));
}
}
for (const auto &entry : help_entries) {
for (const char *name : entry.opt_long) {
if (!entry.arg) {
print(std::format(" [--{}]", name));
continue;
}
if (entry.opt) {
print(std::format(" [--{}[={}]]", name, entry.arg));
} else {
print(std::format(" [--{}={}]", name, entry.arg));
}
}
}
print_usage(name);
std::cout << std::endl;
exit(0);
}

diff --git a/src/trie.cpp b/src/trie.cpp

@@ -0,0 +1,38 @@

#include "args.hpp"
#include <cstdint>
Parser::trie_t::~trie_t() noexcept {
for (uint8_t i = 0; i < 26; i++) {
delete children[i];
}
}
void Parser::trie_t::insert(const std::string &option, int key) {
trie_t *crnt = this;
for (const char c : option) {
if (!crnt->terminal) crnt->key = key;
crnt->count++;
const uint8_t idx = c - 'a';
if (!crnt->children[idx]) crnt->children[idx] = new trie_t();
crnt = crnt->children[idx];
}
crnt->terminal = true;
crnt->key = key;
}
int Parser::trie_t::get(const std::string &option) const {
const trie_t *crnt = this;
for (const char c : option) {
const uint8_t idx = c - 'a';
if (!crnt->children[idx]) return 0;
crnt = crnt->children[idx];
}
if (!crnt->terminal && crnt->count > 1) return 0;
return crnt->key;
}