cpputils/include/cpputils/argparse.h at master · nlitsme/cpputils · GitHub

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* $Header$

#ifndef __ARGS_H__

#include <string>

#include <algorithm>

#include <stdexcept>

#include <stdlib.h>

#include <cpputils/stringlibrary.h>

// cmd -apple -a 1234 first second -

for (auto& arg : ArgParser(argc, argv))

switch (arg.option())

{

case 'a':

if (arg.match("-apple")) {

}

else {

a_arg = arg.getint();

}

break;

case '-':

if (arg.match("--long"))

a_long = true;

break;

case 0:

usestdin = true;

break;

case -1:

switch(n++)

{

case 0: first = arg.getstr(); break;

case 1: second = arg.getstr(); break;

}

// TODO - support floating point numbers

// TODO - support options with multiple arguments.

class ArgParser {

struct ArgIterator {

const char **argv; // argument list

int argc; // nr of argument strings

int i; // current argument

const char *p; // position in current argument

const char *pend; // end of current argument

bool longmatch;

bool isoption;

bool _options_ended = false; // detects '--'

void setcurrent()

{

longmatch = false;

isoption = false;

if (i==argc) {

p = pend = nullptr;

return;

}

p = argv[i];

pend = p + stringlength(p);

}

ArgIterator(const char **argv, int i, int argc)

: argv(argv), argc(argc), i(i)

{

setcurrent();

}

friend bool operator!=(const ArgIterator& lhs, const ArgIterator& rhs)

{

return !(lhs.i==rhs.i && lhs.p == rhs.p);

}

ArgIterator& operator*() { return *this; }

ArgIterator& operator++()

{

if (i==argc)

// calller should throw when nescesary.

return *this;

i++;

setcurrent();

return *this;

}

* get single option character

* returns -1 for non option arguments

* returns 0 for single dash '-'

int option()

{

if (i==argc)

throw std::range_error("arg out of range");

if (!_options_ended && *p=='-') {

// a single '-' by itself is not considered an option,

// so 'getstr()' will return "-"

if (optionterminator())

_options_ended = true;

isoption = p[1]!=0;

return p[1];

}

isoption = false;

return -1;

}

* matches long option names

* the name should include the leading option dash(es)

* like: match("--verbose")

* the caller must make sure the matching order does not

* lead to ambiguities.

* When the name matches, the current ptr will point after the match.

bool match(const char*name)

{

if (i==argc)

throw std::range_error("arg out of range");

auto namelen = stringlength(name);

if (namelen > stringlength(p))

return false;

if (std::equal(name, name+namelen, p)) {

p += namelen;

longmatch = true;

return true;

}

return false;

}

* checks for '--', usually used to end option processing

bool optionterminator()

{

if (i==argc)

throw std::range_error("arg out of range");

if (p+2!=pend)

return false;

return p[0]=='-' && p[1]=='-';

}

* gets the next argument string

* long arguments can have a '=' after the option name

* --number=1234

const char *getstr()

{

if (i==argc)

throw std::range_error("arg out of range");

if (isoption && !longmatch) {

// skips '-' + optionchar

p += 2;

if (*p==0) {

// -opt <space> argument

operator++();

}

// -opt<argument>

}

else if (longmatch) {

// long match need not match the full word.

p = std::find(p, pend, '=');

if (p!=pend) {

// --longopt '=' argument

return p+1;

}

// --longopt <space> argument

operator++();

}

// check again if we are out of options

if (i==argc)

throw std::range_error("arg out of range");

return p;

}

const char*getfullarg()

{

return argv[i];

}

* return count for a repeated option:

* -vvv -> returns 3

int count()

{

if (i==argc)

throw std::range_error("arg out of range");

if (longmatch)

throw std::logic_error("can't count a --long option");

char opt = p[1];

const char *q = p+1;

while (q!=pend && *q==opt)

++q;

if (q!=pend)

throw std::logic_error("counted options must all be equal");

return pend - p - 1;

}

* gets the integer after the current option.

* either in the same string, or in the next full argument.

int64_t getint()

{

getstr(); // ignoring result, we use 'p' directly.

auto res = parsesigned(p, pend, 0);

if (res.second != pend)

throw std::logic_error("characters trailing number");

return res.first;

}

uint64_t getuint()

{

getstr(); // ignoring result, we use 'p' directly.

auto res = parseunsigned(p, pend, 0);

if (res.second != pend)

throw std::logic_error("characters trailing number");

return res.first;

}

double getdouble()

{

getstr(); // ignoring result, we use 'p' directly.

// note: can't use <charconv> std::from_chars<double>, since that is not implemented in libc++ yet.

char *numend;

double res = strtod(p, &numend);

if (numend != pend)

throw std::logic_error("characters trailing number");

return res;

}

};

int argc;

const char **argv;

public:

ArgParser(int argc, const char**argv)

: argc(argc), argv(argv)

{

}

ArgParser(int argc, char**argv)

: argc(argc), argv(const_cast<const char**>(argv))

{

}

auto begin() { return ArgIterator(argv, 1, argc); }

auto end() { return ArgIterator(argv, argc, argc); }

};

#define __ARGS_H__

#endif

cpputils/include/cpputils/argparse.h at master · nlitsme/cpputils · GitHub

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