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mirror of https://github.com/qpdf/qpdf.git synced 2024-09-21 09:39:09 +00:00
qpdf/libqpdf/QPDFArgParser.cc
Jay Berkenbilt 4f24617e1e Code clean up: use range-style for loops wherever possible
Where not possible, use "auto" to get the iterator type.

Editorial note: I have avoid this change for a long time because of
not wanting to make gratuitous changes to version history, which can
obscure when certain changes were made, but with having recently
touched every single file to apply automatic code formatting and with
making several broad changes to the API, I decided it was time to take
the plunge and get rid of the older (pre-C++11) verbose iterator
syntax. The new code is just easier to read and understand, and in
many cases, it will be more effecient as fewer temporary copies are
being made.

m-holger, if you're reading, you can see that I've finally come
around. :-)
2022-04-30 13:27:18 -04:00

857 lines
28 KiB
C++

#include <qpdf/QPDFArgParser.hh>
#include <qpdf/QIntC.hh>
#include <qpdf/QPDFUsage.hh>
#include <qpdf/QTC.hh>
#include <qpdf/QUtil.hh>
#include <cstdlib>
#include <cstring>
#include <iostream>
QPDFArgParser::Members::Members(
int argc, char const* const argv[], char const* progname_env) :
argc(argc),
argv(argv),
progname_env(progname_env),
cur_arg(0),
bash_completion(false),
zsh_completion(false),
option_table(nullptr),
final_check_handler(nullptr)
{
auto tmp = QUtil::make_unique_cstr(argv[0]);
whoami = QUtil::getWhoami(tmp.get());
}
QPDFArgParser::QPDFArgParser(
int argc, char const* const argv[], char const* progname_env) :
m(new Members(argc, argv, progname_env))
{
selectHelpOptionTable();
char const* help_choices[] = {"all", 0};
// More help choices are added dynamically.
addChoices(
"help", bindParam(&QPDFArgParser::argHelp, this), false, help_choices);
addInvalidChoiceHandler(
"help", bindParam(&QPDFArgParser::invalidHelpArg, this));
addBare(
"completion-bash", bindBare(&QPDFArgParser::argCompletionBash, this));
addBare("completion-zsh", bindBare(&QPDFArgParser::argCompletionZsh, this));
selectMainOptionTable();
}
void
QPDFArgParser::selectMainOptionTable()
{
this->m->option_table = &this->m->main_option_table;
this->m->option_table_name = "main";
}
void
QPDFArgParser::selectHelpOptionTable()
{
this->m->option_table = &this->m->help_option_table;
this->m->option_table_name = "help";
}
void
QPDFArgParser::selectOptionTable(std::string const& name)
{
auto t = this->m->option_tables.find(name);
if (t == this->m->option_tables.end()) {
QTC::TC("libtests", "QPDFArgParser select unregistered table");
throw std::logic_error(
"QPDFArgParser: selecting unregistered option table " + name);
}
this->m->option_table = &(t->second);
this->m->option_table_name = name;
}
void
QPDFArgParser::registerOptionTable(
std::string const& name, bare_arg_handler_t end_handler)
{
if (0 != this->m->option_tables.count(name)) {
QTC::TC("libtests", "QPDFArgParser register registered table");
throw std::logic_error(
"QPDFArgParser: registering already registered option table " +
name);
}
this->m->option_tables[name];
selectOptionTable(name);
addBare("--", end_handler);
}
QPDFArgParser::OptionEntry&
QPDFArgParser::registerArg(std::string const& arg)
{
if (0 != this->m->option_table->count(arg)) {
QTC::TC("libtests", "QPDFArgParser duplicate handler");
throw std::logic_error(
"QPDFArgParser: adding a duplicate handler for option " + arg +
" in " + this->m->option_table_name + " option table");
}
return ((*this->m->option_table)[arg]);
}
void
QPDFArgParser::addPositional(param_arg_handler_t handler)
{
OptionEntry& oe = registerArg("");
oe.param_arg_handler = handler;
}
void
QPDFArgParser::addBare(std::string const& arg, bare_arg_handler_t handler)
{
OptionEntry& oe = registerArg(arg);
oe.parameter_needed = false;
oe.bare_arg_handler = handler;
}
void
QPDFArgParser::addRequiredParameter(
std::string const& arg,
param_arg_handler_t handler,
char const* parameter_name)
{
OptionEntry& oe = registerArg(arg);
oe.parameter_needed = true;
oe.parameter_name = parameter_name;
oe.param_arg_handler = handler;
}
void
QPDFArgParser::addOptionalParameter(
std::string const& arg, param_arg_handler_t handler)
{
OptionEntry& oe = registerArg(arg);
oe.parameter_needed = false;
oe.param_arg_handler = handler;
}
void
QPDFArgParser::addChoices(
std::string const& arg,
param_arg_handler_t handler,
bool required,
char const** choices)
{
OptionEntry& oe = registerArg(arg);
oe.parameter_needed = required;
oe.param_arg_handler = handler;
for (char const** i = choices; *i; ++i) {
oe.choices.insert(*i);
}
}
void
QPDFArgParser::addInvalidChoiceHandler(
std::string const& arg, param_arg_handler_t handler)
{
auto i = this->m->option_table->find(arg);
if (i == this->m->option_table->end()) {
QTC::TC("libtests", "QPDFArgParser invalid choice handler to unknown");
throw std::logic_error(
"QPDFArgParser: attempt to add invalid choice handler"
" to unknown argument");
}
auto& oe = i->second;
oe.invalid_choice_handler = handler;
}
void
QPDFArgParser::addFinalCheck(bare_arg_handler_t handler)
{
this->m->final_check_handler = handler;
}
bool
QPDFArgParser::isCompleting() const
{
return this->m->bash_completion;
}
int
QPDFArgParser::argsLeft() const
{
return this->m->argc - this->m->cur_arg - 1;
}
void
QPDFArgParser::insertCompletion(std::string const& arg)
{
this->m->completions.insert(arg);
}
void
QPDFArgParser::completionCommon(bool zsh)
{
std::string progname = this->m->argv[0];
std::string executable;
std::string appdir;
std::string appimage;
if (QUtil::get_env(this->m->progname_env.c_str(), &executable)) {
progname = executable;
} else if (
QUtil::get_env("APPDIR", &appdir) &&
QUtil::get_env("APPIMAGE", &appimage)) {
// Detect if we're in an AppImage and adjust
if ((appdir.length() < strlen(this->m->argv[0])) &&
(strncmp(appdir.c_str(), this->m->argv[0], appdir.length()) == 0)) {
progname = appimage;
}
}
if (zsh) {
std::cout << "autoload -U +X bashcompinit && bashcompinit && ";
}
std::cout << "complete -o bashdefault -o default";
if (!zsh) {
std::cout << " -o nospace";
}
std::cout << " -C " << progname << " " << this->m->whoami << std::endl;
// Put output before error so calling from zsh works properly
std::string path = progname;
size_t slash = path.find('/');
if ((slash != 0) && (slash != std::string::npos)) {
std::cerr << "WARNING: " << this->m->whoami << " completion enabled"
<< " using relative path to executable" << std::endl;
}
}
void
QPDFArgParser::argCompletionBash()
{
completionCommon(false);
}
void
QPDFArgParser::argCompletionZsh()
{
completionCommon(true);
}
void
QPDFArgParser::argHelp(std::string const& p)
{
std::cout << getHelp(p);
exit(0);
}
void
QPDFArgParser::invalidHelpArg(std::string const& p)
{
usage(std::string("unknown help option") + (p.empty() ? "" : (" " + p)));
}
void
QPDFArgParser::handleArgFileArguments()
{
// Support reading arguments from files. Create a new argv. Ensure
// that argv itself as well as all its contents are automatically
// deleted by using shared pointers to back the pointers in argv.
this->m->new_argv.push_back(QUtil::make_shared_cstr(this->m->argv[0]));
for (int i = 1; i < this->m->argc; ++i) {
char const* argfile = 0;
if ((strlen(this->m->argv[i]) > 1) && (this->m->argv[i][0] == '@')) {
argfile = 1 + this->m->argv[i];
if (strcmp(argfile, "-") != 0) {
if (!QUtil::file_can_be_opened(argfile)) {
// The file's not there; treating as regular option
argfile = nullptr;
}
}
}
if (argfile) {
readArgsFromFile(1 + this->m->argv[i]);
} else {
this->m->new_argv.push_back(
QUtil::make_shared_cstr(this->m->argv[i]));
}
}
this->m->argv_ph =
QUtil::make_shared_array<char const*>(1 + this->m->new_argv.size());
for (size_t i = 0; i < this->m->new_argv.size(); ++i) {
this->m->argv_ph.get()[i] = this->m->new_argv.at(i).get();
}
this->m->argc = QIntC::to_int(this->m->new_argv.size());
this->m->argv_ph.get()[this->m->argc] = nullptr;
this->m->argv = this->m->argv_ph.get();
}
void
QPDFArgParser::handleBashArguments()
{
// Do a minimal job of parsing bash_line into arguments. This
// doesn't do everything the shell does (e.g. $(...), variable
// expansion, arithmetic, globs, etc.), but it should be good
// enough for purposes of handling completion. As we build up the
// new argv, we can't use this->m->new_argv because this code has to
// interoperate with @file arguments, so memory for both ways of
// fabricating argv has to be protected.
bool last_was_backslash = false;
enum { st_top, st_squote, st_dquote } state = st_top;
std::string arg;
for (char ch: this->m->bash_line) {
if (last_was_backslash) {
arg.append(1, ch);
last_was_backslash = false;
} else if (ch == '\\') {
last_was_backslash = true;
} else {
bool append = false;
switch (state) {
case st_top:
if (QUtil::is_space(ch)) {
if (!arg.empty()) {
this->m->bash_argv.push_back(
QUtil::make_shared_cstr(arg));
arg.clear();
}
} else if (ch == '"') {
state = st_dquote;
} else if (ch == '\'') {
state = st_squote;
} else {
append = true;
}
break;
case st_squote:
if (ch == '\'') {
state = st_top;
} else {
append = true;
}
break;
case st_dquote:
if (ch == '"') {
state = st_top;
} else {
append = true;
}
break;
}
if (append) {
arg.append(1, ch);
}
}
}
if (this->m->bash_argv.empty()) {
// This can't happen if properly invoked by bash, but ensure
// we have a valid argv[0] regardless.
this->m->bash_argv.push_back(QUtil::make_shared_cstr(this->m->argv[0]));
}
// Explicitly discard any non-space-terminated word. The "current
// word" is handled specially.
this->m->bash_argv_ph =
QUtil::make_shared_array<char const*>(1 + this->m->bash_argv.size());
for (size_t i = 0; i < this->m->bash_argv.size(); ++i) {
this->m->bash_argv_ph.get()[i] = this->m->bash_argv.at(i).get();
}
this->m->argc = QIntC::to_int(this->m->bash_argv.size());
this->m->bash_argv_ph.get()[this->m->argc] = nullptr;
this->m->argv = this->m->bash_argv_ph.get();
}
void
QPDFArgParser::usage(std::string const& message)
{
if (this->m->bash_completion) {
// This will cause bash to fall back to regular file completion.
exit(0);
}
throw QPDFUsage(message);
}
void
QPDFArgParser::readArgsFromFile(std::string const& filename)
{
std::list<std::string> lines;
if (filename == "-") {
QTC::TC("libtests", "QPDFArgParser read args from stdin");
lines = QUtil::read_lines_from_file(std::cin);
} else {
QTC::TC("libtests", "QPDFArgParser read args from file");
lines = QUtil::read_lines_from_file(filename.c_str());
}
for (auto const& line: lines) {
this->m->new_argv.push_back(QUtil::make_shared_cstr(line));
}
}
void
QPDFArgParser::checkCompletion()
{
// See if we're being invoked from bash completion.
std::string bash_point_env;
// On Windows with mingw, there have been times when there appears
// to be no way to distinguish between an empty environment
// variable and an unset variable. There are also conditions under
// which bash doesn't set COMP_LINE. Therefore, enter this logic
// if either COMP_LINE or COMP_POINT are set. They will both be
// set together under ordinary circumstances.
bool got_line = QUtil::get_env("COMP_LINE", &this->m->bash_line);
bool got_point = QUtil::get_env("COMP_POINT", &bash_point_env);
if (got_line || got_point) {
size_t p = QUtil::string_to_uint(bash_point_env.c_str());
if (p < this->m->bash_line.length()) {
// Truncate the line. We ignore everything at or after the
// cursor for completion purposes.
this->m->bash_line = this->m->bash_line.substr(0, p);
}
if (p > this->m->bash_line.length()) {
p = this->m->bash_line.length();
}
// Set bash_cur and bash_prev based on bash_line rather than
// relying on argv. This enables us to use bashcompinit to get
// completion in zsh too since bashcompinit sets COMP_LINE and
// COMP_POINT but doesn't invoke the command with options like
// bash does.
// p is equal to length of the string. Walk backwards looking
// for the first separator. bash_cur is everything after the
// last separator, possibly empty.
char sep(0);
while (p > 0) {
--p;
char ch = this->m->bash_line.at(p);
if ((ch == ' ') || (ch == '=') || (ch == ':')) {
sep = ch;
break;
}
}
if (1 + p <= this->m->bash_line.length()) {
this->m->bash_cur =
this->m->bash_line.substr(1 + p, std::string::npos);
}
if ((sep == ':') || (sep == '=')) {
// Bash sets prev to the non-space separator if any.
// Actually, if there are multiple separators in a row,
// they are all included in prev, but that detail is not
// important to us and not worth coding.
this->m->bash_prev = this->m->bash_line.substr(p, 1);
} else {
// Go back to the last separator and set prev based on
// that.
size_t p1 = p;
while (p1 > 0) {
--p1;
char ch = this->m->bash_line.at(p1);
if ((ch == ' ') || (ch == ':') || (ch == '=')) {
this->m->bash_prev =
this->m->bash_line.substr(p1 + 1, p - p1 - 1);
break;
}
}
}
if (this->m->bash_prev.empty()) {
this->m->bash_prev = this->m->bash_line.substr(0, p);
}
if (this->m->argc == 1) {
// This is probably zsh using bashcompinit. There are a
// few differences in the expected output.
this->m->zsh_completion = true;
}
handleBashArguments();
this->m->bash_completion = true;
}
}
void
QPDFArgParser::parseArgs()
{
selectMainOptionTable();
checkCompletion();
handleArgFileArguments();
for (this->m->cur_arg = 1; this->m->cur_arg < this->m->argc;
++this->m->cur_arg) {
bool help_option = false;
bool end_option = false;
auto oep = this->m->option_table->end();
char const* arg = this->m->argv[this->m->cur_arg];
std::string parameter;
bool have_parameter = false;
std::string o_arg(arg);
std::string arg_s(arg);
if (strcmp(arg, "--") == 0) {
// Special case for -- option, which is used to break out
// of subparsers.
oep = this->m->option_table->find("--");
end_option = true;
if (oep == this->m->option_table->end()) {
// This is registered automatically, so this can't happen.
throw std::logic_error(
"QPDFArgParser: -- handler not registered");
}
} else if ((arg[0] == '-') && (strcmp(arg, "-") != 0)) {
++arg;
if (arg[0] == '-') {
// Be lax about -arg vs --arg
++arg;
} else {
QTC::TC("libtests", "QPDFArgParser single dash");
}
// Prevent --=something from being treated as an empty arg
// by searching for = from after the first character. We
// do this since the empty string in the option table is
// for positional arguments. Besides, it doesn't make
// sense to have an empty option.
arg_s = arg;
size_t equal_pos = std::string::npos;
if (arg_s.length() > 0) {
equal_pos = arg_s.find('=', 1);
}
if (equal_pos != std::string::npos) {
have_parameter = true;
parameter = arg_s.substr(equal_pos + 1);
arg_s = arg_s.substr(0, equal_pos);
}
if ((!this->m->bash_completion) && (this->m->argc == 2) &&
(this->m->cur_arg == 1) &&
this->m->help_option_table.count(arg_s)) {
// Handle help option, which is only valid as the sole
// option.
QTC::TC("libtests", "QPDFArgParser help option");
oep = this->m->help_option_table.find(arg_s);
help_option = true;
}
if (!(help_option || arg_s.empty() || (arg_s.at(0) == '-'))) {
oep = this->m->option_table->find(arg_s);
}
} else {
// The empty string maps to the positional argument
// handler.
QTC::TC("libtests", "QPDFArgParser positional");
oep = this->m->option_table->find("");
parameter = arg;
}
if (oep == this->m->option_table->end()) {
QTC::TC("libtests", "QPDFArgParser unrecognized");
std::string message = "unrecognized argument " + o_arg;
if (this->m->option_table != &this->m->main_option_table) {
message += " (" + this->m->option_table_name +
" options must be terminated with --)";
}
usage(message);
}
OptionEntry& oe = oep->second;
if ((oe.parameter_needed && (!have_parameter)) ||
((!oe.choices.empty() && have_parameter &&
(0 == oe.choices.count(parameter))))) {
std::string message =
"--" + arg_s + " must be given as --" + arg_s + "=";
if (oe.invalid_choice_handler) {
oe.invalid_choice_handler(parameter);
// Method should call usage() or exit. Just in case it
// doesn't...
message += "option";
} else if (!oe.choices.empty()) {
QTC::TC("libtests", "QPDFArgParser required choices");
message += "{";
bool first = true;
for (auto const& choice: oe.choices) {
if (first) {
first = false;
} else {
message += ",";
}
message += choice;
}
message += "}";
} else if (!oe.parameter_name.empty()) {
QTC::TC("libtests", "QPDFArgParser required parameter");
message += oe.parameter_name;
} else {
// should not be possible
message += "option";
}
usage(message);
}
if (oe.bare_arg_handler) {
oe.bare_arg_handler();
} else if (oe.param_arg_handler) {
oe.param_arg_handler(parameter);
}
if (help_option) {
exit(0);
}
if (end_option) {
selectMainOptionTable();
}
}
if (this->m->bash_completion) {
handleCompletion();
} else {
doFinalChecks();
}
}
std::string
QPDFArgParser::getProgname()
{
return this->m->whoami;
}
void
QPDFArgParser::doFinalChecks()
{
if (this->m->option_table != &(this->m->main_option_table)) {
QTC::TC("libtests", "QPDFArgParser missing --");
usage(
"missing -- at end of " + this->m->option_table_name + " options");
}
if (this->m->final_check_handler != nullptr) {
this->m->final_check_handler();
}
}
void
QPDFArgParser::addChoicesToCompletions(
option_table_t& option_table,
std::string const& option,
std::string const& extra_prefix)
{
if (option_table.count(option) != 0) {
OptionEntry& oe = option_table[option];
for (auto const& choice: oe.choices) {
QTC::TC("libtests", "QPDFArgParser complete choices");
this->m->completions.insert(extra_prefix + choice);
}
}
}
void
QPDFArgParser::addOptionsToCompletions(option_table_t& option_table)
{
for (auto& iter: option_table) {
std::string const& arg = iter.first;
if (arg == "--") {
continue;
}
OptionEntry& oe = iter.second;
std::string base = "--" + arg;
if (oe.param_arg_handler) {
if (this->m->zsh_completion) {
// zsh doesn't treat = as a word separator, so add all
// the options so we don't get a space after the =.
addChoicesToCompletions(option_table, arg, base + "=");
}
this->m->completions.insert(base + "=");
}
if (!oe.parameter_needed) {
this->m->completions.insert(base);
}
}
}
void
QPDFArgParser::insertCompletions(
option_table_t& option_table,
std::string const& choice_option,
std::string const& extra_prefix)
{
if (!choice_option.empty()) {
addChoicesToCompletions(option_table, choice_option, extra_prefix);
} else if (
(!this->m->bash_cur.empty()) && (this->m->bash_cur.at(0) == '-')) {
addOptionsToCompletions(option_table);
}
}
void
QPDFArgParser::handleCompletion()
{
std::string extra_prefix;
if (this->m->completions.empty()) {
// Detect --option=... Bash treats the = as a word separator.
std::string choice_option;
if (this->m->bash_cur.empty() && (this->m->bash_prev.length() > 2) &&
(this->m->bash_prev.at(0) == '-') &&
(this->m->bash_prev.at(1) == '-') &&
(this->m->bash_line.at(this->m->bash_line.length() - 1) == '=')) {
choice_option = this->m->bash_prev.substr(2, std::string::npos);
} else if (
(this->m->bash_prev == "=") &&
(this->m->bash_line.length() > (this->m->bash_cur.length() + 1))) {
// We're sitting at --option=x. Find previous option.
size_t end_mark =
this->m->bash_line.length() - this->m->bash_cur.length() - 1;
char before_cur = this->m->bash_line.at(end_mark);
if (before_cur == '=') {
size_t space = this->m->bash_line.find_last_of(' ', end_mark);
if (space != std::string::npos) {
std::string candidate = this->m->bash_line.substr(
space + 1, end_mark - space - 1);
if ((candidate.length() > 2) && (candidate.at(0) == '-') &&
(candidate.at(1) == '-')) {
choice_option = candidate.substr(2, std::string::npos);
}
}
}
}
if (this->m->zsh_completion && (!choice_option.empty())) {
// zsh wants --option=choice rather than just choice
extra_prefix = "--" + choice_option + "=";
}
insertCompletions(*this->m->option_table, choice_option, extra_prefix);
if (this->m->argc == 1) {
// Help options are valid only by themselves.
insertCompletions(
this->m->help_option_table, choice_option, extra_prefix);
}
}
std::string prefix = extra_prefix + this->m->bash_cur;
for (auto const& iter: this->m->completions) {
if (prefix.empty() || (iter.substr(0, prefix.length()) == prefix)) {
std::cout << iter << std::endl;
}
}
exit(0);
}
void
QPDFArgParser::addHelpFooter(std::string const& text)
{
this->m->help_footer = "\n" + text;
}
void
QPDFArgParser::addHelpTopic(
std::string const& topic,
std::string const& short_text,
std::string const& long_text)
{
if (topic == "all") {
QTC::TC("libtests", "QPDFArgParser add reserved help topic");
throw std::logic_error(
"QPDFArgParser: can't register reserved help topic " + topic);
}
if (!((topic.length() > 0) && (topic.at(0) != '-'))) {
QTC::TC("libtests", "QPDFArgParser bad topic for help");
throw std::logic_error(
"QPDFArgParser: help topics must not start with -");
}
if (this->m->help_topics.count(topic)) {
QTC::TC("libtests", "QPDFArgParser add existing topic");
throw std::logic_error(
"QPDFArgParser: topic " + topic + " has already been added");
}
this->m->help_topics[topic] = HelpTopic(short_text, long_text);
this->m->help_option_table["help"].choices.insert(topic);
}
void
QPDFArgParser::addOptionHelp(
std::string const& option_name,
std::string const& topic,
std::string const& short_text,
std::string const& long_text)
{
if (!((option_name.length() > 2) && (option_name.at(0) == '-') &&
(option_name.at(1) == '-'))) {
QTC::TC("libtests", "QPDFArgParser bad option for help");
throw std::logic_error(
"QPDFArgParser: options for help must start with --");
}
if (this->m->option_help.count(option_name)) {
QTC::TC("libtests", "QPDFArgParser duplicate option help");
throw std::logic_error(
"QPDFArgParser: option " + option_name + " already has help");
}
auto ht = this->m->help_topics.find(topic);
if (ht == this->m->help_topics.end()) {
QTC::TC("libtests", "QPDFArgParser add to unknown topic");
throw std::logic_error(
"QPDFArgParser: unable to add option " + option_name +
" to unknown help topic " + topic);
}
this->m->option_help[option_name] = HelpTopic(short_text, long_text);
ht->second.options.insert(option_name);
this->m->help_option_table["help"].choices.insert(option_name);
}
void
QPDFArgParser::getTopHelp(std::ostringstream& msg)
{
msg << "Run \"" << this->m->whoami << " --help=topic\" for help on a topic."
<< std::endl
<< "Run \"" << this->m->whoami
<< " --help=--option\" for help on an option." << std::endl
<< "Run \"" << this->m->whoami
<< " --help=all\" to see all available help." << std::endl
<< std::endl
<< "Topics:" << std::endl;
for (auto const& i: this->m->help_topics) {
msg << " " << i.first << ": " << i.second.short_text << std::endl;
}
}
void
QPDFArgParser::getAllHelp(std::ostringstream& msg)
{
getTopHelp(msg);
auto show = [this, &msg](std::map<std::string, HelpTopic>& topics) {
for (auto const& i: topics) {
auto const& topic = i.first;
msg << std::endl
<< "== " << topic << " (" << i.second.short_text
<< ") ==" << std::endl
<< std::endl;
getTopicHelp(topic, i.second, msg);
}
};
show(this->m->help_topics);
show(this->m->option_help);
msg << std::endl << "====" << std::endl;
}
void
QPDFArgParser::getTopicHelp(
std::string const& name, HelpTopic const& ht, std::ostringstream& msg)
{
if (ht.long_text.empty()) {
msg << ht.short_text << std::endl;
} else {
msg << ht.long_text;
}
if (!ht.options.empty()) {
msg << std::endl << "Related options:" << std::endl;
for (auto const& i: ht.options) {
msg << " " << i << ": " << this->m->option_help[i].short_text
<< std::endl;
}
}
}
std::string
QPDFArgParser::getHelp(std::string const& arg)
{
std::ostringstream msg;
if (arg.empty()) {
getTopHelp(msg);
} else {
if (arg == "all") {
getAllHelp(msg);
} else if (this->m->option_help.count(arg)) {
getTopicHelp(arg, this->m->option_help[arg], msg);
} else if (this->m->help_topics.count(arg)) {
getTopicHelp(arg, this->m->help_topics[arg], msg);
} else {
// should not be possible
getTopHelp(msg);
}
}
msg << this->m->help_footer;
return msg.str();
}