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#include "args.hh"
#include "hash.hh"
namespace nix {
Args::FlagMaker Args::mkFlag()
{
return FlagMaker(*this);
}
Args::FlagMaker::~FlagMaker()
{
assert(flag->longName != "");
args.longFlags[flag->longName] = flag;
if (flag->shortName) args.shortFlags[flag->shortName] = flag;
}
void Args::parseCmdline(const Strings & _cmdline)
{
Strings pendingArgs;
bool dashDash = false;
Strings cmdline(_cmdline);
for (auto pos = cmdline.begin(); pos != cmdline.end(); ) {
auto arg = *pos;
/* Expand compound dash options (i.e., `-qlf' -> `-q -l -f',
`-j3` -> `-j 3`). */
if (!dashDash && arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && isalpha(arg[1])) {
*pos = (string) "-" + arg[1];
auto next = pos; ++next;
for (unsigned int j = 2; j < arg.length(); j++)
if (isalpha(arg[j]))
cmdline.insert(next, (string) "-" + arg[j]);
else {
cmdline.insert(next, string(arg, j));
break;
}
arg = *pos;
}
if (!dashDash && arg == "--") {
dashDash = true;
++pos;
}
else if (!dashDash && std::string(arg, 0, 1) == "-") {
if (!processFlag(pos, cmdline.end()))
throw UsageError(format("unrecognised flag ‘%1%’") % arg);
}
else {
pendingArgs.push_back(*pos++);
if (processArgs(pendingArgs, false))
pendingArgs.clear();
}
}
processArgs(pendingArgs, true);
}
void Args::printHelp(const string & programName, std::ostream & out)
{
std::cout << "Usage: " << programName << " <FLAGS>...";
for (auto & exp : expectedArgs) {
std::cout << renderLabels({exp.label});
// FIXME: handle arity > 1
if (exp.arity == 0) std::cout << "...";
if (exp.optional) std::cout << "?";
}
std::cout << "\n";
auto s = description();
if (s != "")
std::cout << "\nSummary: " << s << ".\n";
if (longFlags.size()) {
std::cout << "\n";
std::cout << "Flags:\n";
printFlags(out);
}
}
void Args::printFlags(std::ostream & out)
{
Table2 table;
for (auto & flag : longFlags) {
if (hiddenCategories.count(flag.second->category)) continue;
table.push_back(std::make_pair(
(flag.second->shortName ? std::string("-") + flag.second->shortName + ", " : " ")
+ "--" + flag.first + renderLabels(flag.second->labels),
flag.second->description));
}
printTable(out, table);
}
bool Args::processFlag(Strings::iterator & pos, Strings::iterator end)
{
assert(pos != end);
auto process = [&](const std::string & name, const Flag & flag) -> bool {
++pos;
Strings args;
for (size_t n = 0 ; n < flag.arity; ++n) {
if (pos == end)
throw UsageError(format("flag ‘%1%’ requires %2% argument(s)")
% name % flag.arity);
args.push_back(*pos++);
}
flag.handler(args);
return true;
};
if (string(*pos, 0, 2) == "--") {
auto i = longFlags.find(string(*pos, 2));
if (i == longFlags.end()) return false;
return process("--" + i->first, *i->second);
}
if (string(*pos, 0, 1) == "-" && pos->size() == 2) {
auto c = (*pos)[1];
auto i = shortFlags.find(c);
if (i == shortFlags.end()) return false;
return process(std::string("-") + c, *i->second);
}
return false;
}
bool Args::processArgs(const Strings & args, bool finish)
{
if (expectedArgs.empty()) {
if (!args.empty())
throw UsageError(format("unexpected argument ‘%1%’") % args.front());
return true;
}
auto & exp = expectedArgs.front();
bool res = false;
if ((exp.arity == 0 && finish) ||
(exp.arity > 0 && args.size() == exp.arity))
{
exp.handler(args);
expectedArgs.pop_front();
res = true;
}
if (finish && !expectedArgs.empty() && !expectedArgs.front().optional)
throw UsageError("more arguments are required");
return res;
}
void Args::mkHashTypeFlag(const std::string & name, HashType * ht)
{
mkFlag1(0, name, "TYPE", "hash algorithm (‘md5’, ‘sha1’, ‘sha256’, or ‘sha512’)", [=](std::string s) {
*ht = parseHashType(s);
if (*ht == htUnknown)
throw UsageError(format("unknown hash type ‘%1%’") % s);
});
}
Strings argvToStrings(int argc, char * * argv)
{
Strings args;
argc--; argv++;
while (argc--) args.push_back(*argv++);
return args;
}
std::string renderLabels(const Strings & labels)
{
std::string res;
for (auto label : labels) {
for (auto & c : label) c = std::toupper(c);
res += " <" + label + ">";
}
return res;
}
void printTable(std::ostream & out, const Table2 & table)
{
size_t max = 0;
for (auto & row : table)
max = std::max(max, row.first.size());
for (auto & row : table) {
out << " " << row.first
<< std::string(max - row.first.size() + 2, ' ')
<< row.second << "\n";
}
}
}
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