/* See LICENSE file for copyright and license details. */
#ifndef LIBSIMPLE_ARG_H
#define LIBSIMPLE_ARG_H
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/**
* The zeroth command line argument, the name of the process,
* set by the command line parsing macros
*/
extern char *argv0;
struct longopt {
const char *long_flag;
char short_flag;
int with_arg;
};
/**
* `ARGBEGIN {} ARGEND;` creates a switch statement
* instead a loop that parses the command line arguments
* according to the POSIX specification for default
* behaviour (extensions of the behaviour is possible)
*
* This macro requires that the variables `argc` and
* `argv` are defined and that `argv[argc]` is `NULL`,
* `argc` shall be a non-negative `int` that tells
* how many elements (all non-`NULL`) are available in
* `argv`, the list of command line arguments
*
* When parsing stops, `argc` and `argv` are updated
* shuch that all parsed arguments are removed; the
* contents of `argv` will not be modified, rather
* the pointer `argv` will be updated to `&argv[n]`
* where `n` is the number of parsed elements in `argv`
*
* Inside `{}` in `ARGBEGIN {} ARGEND;` there user
* shall specify `case` statements for each recognised
* command line option, and `default` for unrecognised
* option. For example:
*
* ARGBEGIN {
* case 'a':
* // handle -a
* break;
* case 'b':
* // handle -b
* break;
* case ARGNUM:
* // handle -0, -1, -2, ..., -9
* break;
* default:
* // print usage information for other flags
* usage();
* } ARGEND;
*/
#define ARGBEGIN ARGBEGIN3(1, argc, argv)
/**
* `SUBARGBEGIN {} ARGEND;` is similar to
* `ARGBEGIN {} ARGEND;`, however, `argv0`
* is not set to `argv[0]`, instead `argv[0]`
* is handled like any other element in `argv`
*/
#define SUBARGBEGIN ARGBEGIN3(0, argc, argv)
/**
* Flexible alternative to `ARGBEGIN`
*
* @param WITH_ARGV0 If 0, behave like `SUBARGBEGIN`,
* otherwise, behave like `ARGBEGIN`
* @param argc:int The number of elements in `argv`, will be
* update to the number of arguments remaining
* after parsing stopped
* @param argv:char ** The command line arguments to parse,
* `argv[argc]` must be `NULL`; will be updated,
* via offseting, to the arguments remaining
* after parsing stopped, `argv[argc]` will
* still be `NULL`
*/
#define ARGBEGIN3(WITH_ARGV0, argc, argv)\
do {\
char flag_, *lflag_, *arg_;\
int brk_ = 0, again_;\
size_t i_, n_;\
if (WITH_ARGV0) {\
argv0 = *argv;\
argv += !!argv0;\
argc -= !!argv0;\
}\
for (; argv[0] && argv[0][0] && argv[0][1]; argc--, argv++) {\
lflag_ = argv[0];\
if (argv[0][0] == '-') {\
if (argv[0][1] == '-' && !argv[0][2]) {\
argv++, argc--;\
break;\
}\
for (argv[0]++; argv[0][0]; argv[0]++) {\
flag_ = argv[0][0];\
if (flag_ == '-' && &argv[0][-1] != lflag_)\
usage();\
arg_ = argv[0][1] ? &argv[0][1] : argv[1];\
do {\
again_ = 0;\
switch (flag_) {
/**
* TODO doc ARGMAPLONG
*/
#define ARGMAPLONG(LONGOPTS)\
for (i_ = 0; (LONGOPTS)[i_].long_flag; i_++) {\
if (TESTLONG((LONGOPTS)[i_].long_flag, (LONGOPTS)[i_].with_arg)) {\
flag_ = (LONGOPTS)[i_].short_flag;\
again_ = 1;\
break;\
}\
}\
if (again_)\
break
/**
* Allows flags to start with another symbol than '-'
*
* Usage example:
* ARGBEGIN {
* case 'a': // handle -a
* break;
* default:
* usage();
* } ARGALT('+') {
* case 'a': // handle +a
* break;
* default:
* usage();
* } ARGALT('/') {
* case 'a': // handle /a
* break;
* default:
* usage();
* } ARGEND;
*
* @param SYMBOL:char The symbol flags should begin with
*/
#define ARGALT(SYMBOL)\
}\
} while (again_);\
if (brk_) {\
argc -= arg_ == argv[1];\
argv += arg_ == argv[1];\
brk_ = 0;\
break;\
}\
}\
} else if (argv[0][0] == SYMBOL) {\
if (argv[0][1] == SYMBOL && !argv[0][2])\
break;\
for (argv[0]++; argv[0][0]; argv[0]++) {\
flag_ = argv[0][0];\
if (flag_ == SYMBOL && &argv[0][-1] != lflag_)\
usage();\
arg_ = argv[0][1] ? &argv[0][1] : argv[1];\
do {\
again_ = 0;\
switch (flag_) {
/**
* Refer to `ARGBEGIN`, `SUBARGBEGIN`, and `ARGBEGIN3`
*/
#define ARGEND\
}\
} while (again_);\
if (brk_) {\
argc -= arg_ == argv[1];\
argv += arg_ == argv[1];\
brk_ = 0;\
break;\
}\
}\
} else {\
break;\
}\
}\
} while (0)
/**
* `case ARGNUM` creates a switch statement case for each digit
*/
#define ARGNUM '0': case '1': case '2': case '3': case '4':\
case '5': case '6': case '7': case '8': case '9'
/**
* Get the flag character, for example in `case 'a'`,
* 'a' is returned
*
* @return :char The option's identifying character
*/
#define FLAG() (flag_)
/**
* Get the entire argument that is being parsed
*
* Note that an argument can contain multiple options
* and it can contain the last options value but the
* value can also be in the next argument
*
* @return :char * The current command line argument
*/
#define LFLAG() (lflag_)
/**
* Get the current option's value, if it
* does not have a value, call `usage`
* (which terminates the process)
*
* Using this macro lets the parser knows
* that the option has a value
*
* @return :char * The option's value, never `NULL`
*/
#define ARG() (arg_ ? (brk_ = 1, arg_) : (usage(), NULL))
/**
* Get the current option's value, if the option
* does not have a value, `NULL` is returned
*
* Note that the value may appear at the next
* argument (next element in `argv`) which in that
* case is returned
*
* Using this macro lets the parser knows
* that the option has a value
*
* @return :char * The option's value, `NULL` if
* the option does not have a value
*/
#define ARGNULL() (arg_ ? (brk_ = 1, arg_) : NULL)
/**
* Get the remaining part of the current command
* line argument (element in `argv`) — as well as
* the character that specifies the flag — as the
* value of the argument
*
* Using this macro lets the parser knows
* that the option has a value
*
* Usage example:
*
* char *arg;
* ARGBEGIN {
* case ARGNUM:
* arg = ARGHERE();
* // `arg` is the number after '-', for example,
* // if the command line contains the argument
* // "-12345", `arg` will be `12345`
* break;
* case 'n':
* arg = &ARGHERE()[1];
* if (*arg) {
* // flag 'n' has a value (`argv`)
* } else {
* // flag 'n' does not have a value
* }
* default:
* usage();
* } ARGEND;
*
* @return :char * The option's value include the flag
* character, never `NULL` or ""
*/
#define ARGHERE() (brk_ = 1, argv[0])
/**
* `NOFLAG(x);` is an optimised shorthand for
*
* ARGBEGIN {
* default:
* usage();
* } ARGEND;
*
* if (x)
* usage();
*
* @param ... If non-zero, the `usage` function
* will be called
*/
#define NOFLAGS(...)\
do {\
if (*argv)\
argv0 = *argv++, argc--;\
if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && !argv[0][2])\
argv++, argc--;\
else if (argv[0] && argv[0][0] == '-')\
usage();\
if (__VA_ARGS__)\
usage();\
} while (0)
/**
* TODO doc NOFLAGS
*/
#define TESTLONG(FLG, WARG)\
((WARG)\
? ((!strncmp(lflag_, (FLG), n_ = strlen(FLG)) && lflag_[n_] == '=')\
? (lflag_[n_] = '\0',\
(arg_ = &lflag_[n_ + 1]),\
(brk_ = 1))\
: (!strcmp(lflag_, (FLG))\
? (argv[1]\
? ((arg_ = argv[1]),\
(brk_ = 1))\
: (usage(), 0))\
: 0))\
: (!strcmp(lflag_, (FLG))\
? (brk_ = 1)\
: 0))
/**
* Define the function `static void usage(void)`
* that prints the error message
* "usage: %s %s\n", argv0, SYNOPSIS
* or
* "usage: %s\n", argv0
* if `SYNOPSIS` is `NULL` or "", and then
* terminate the process with exit value 1
*
* This macro also defines `char *argv0`
*
* @param SYNOPSIS Description of the command line argument syntax
*/
#define USAGE(SYNOPSIS)\
NUSAGE(1, SYNOPSIS)
/**
* Define the function `static void usage(void)`
* that prints the error message
* "usage: %s %s\n", argv0, SYNOPSIS
* or
* "usage: %s\n", argv0
* if `SYNOPSIS` is `NULL` or "", and then
* terminate the process with exit value `STATUS`
*
* This macro also defines `char *argv0`
*
* @param SYNOPSIS Description of the command line argument syntax
* @parma STATUS The exit value for the process
*/
#if defined(__GNUC__) || defined(__clang__)
# define NUSAGE(STATUS, SYNOPSIS)\
__attribute__((noreturn))\
static void usage(void)\
{\
const char *syn = SYNOPSIS ? SYNOPSIS : "";\
fprintf(stderr, "usage: %s%s%s\n", argv0, *syn ? " " : "", syn);\
exit(STATUS);\
}\
char *argv0 = NULL
#else
# define NUSAGE(STATUS, SYNOPSIS)\
static void usage(void)\
{\
const char *syn = SYNOPSIS ? SYNOPSIS : "";\
fprintf(stderr, "usage: %s%s%s\n", argv0, *syn ? " " : "", syn);\
exit(STATUS);\
}\
char *argv0 = NULL
#endif
#endif
