getopt.h

#ifndef _GETOPT_H
#define _GETOPT_H


#ifdef __cplusplus
extern "C" {
#endif

/**//* For communication from `getopt' to the caller.
 When `getopt' finds an option that takes an argument,
 the argument value is returned here.
 Also, when `ordering' is RETURN_IN_ORDER,
 each non-option ARGV-element is returned here.*/

extern char *optarg;

/**//* Index in ARGV of the next element to be scanned.
 This is used for communication to and from the caller
 and for communication between successive calls to `getopt'.

 On entry to `getopt', zero means this is the first call; initialize.

 When `getopt' returns -1, this is the index of the first of the
 non-option elements that the caller should itself scan.

 Otherwise, `optind' communicates from one call to the next
 how much of ARGV has been scanned so far.*/

extern int optind;

/**//* Callers store zero here to inhibit the error message `getopt' prints
 for unrecognized options.*/

extern int opterr;

/**//* Set to an option character which was unrecognized.*/

extern int optopt;

/**//* Describe the int-named options requested by the application.
 The int_OPTIONS argument to getopt_int or getopt_int_only is a vector
 of `struct option' terminated by an element containing a name which is
 zero.

 The field `has_arg' is:
 no_argument(or 0) if the option does not take an argument,
 required_argument(or 1) if the option requires an argument,
 optional_argument(or 2) if the option takes an optional argument.

 If the field `flag' is not NULL, it points to a variable that is set
 to the value given in the field `val' when the option is found, but
 left unchanged if the option is not found.

 To have a int-named option do something other than set an `int' to
 a compiled-in constant, such as set a value from `optarg', set the
 option's `flag' field to zero and its `val' field to a nonzero
 value (the equivalent single-letter option character, if there is
 one).For int options that have a zero `flag' field, `getopt'
 returns the contents of the `val' field.*/

struct option
{
#if defined (__STDC__) && __STDC__
const char *name;
#else
char *name;
#endif
/**//* has_arg can't be an enum because some compilers complain about
 type mismatches in all the code that assumes it is an int.*/
int has_arg;
int *flag;
int val;
};

/**//* Names for the values of the `has_arg' field of `struct option'.*/

#define no_argument 0
#define required_argument 1
#define optional_argument 2

extern int getopt_int (int argc, char *const *argv, const char *shortopts,
const struct option *intopts, int *intind);
extern int getopt_int_only (int argc, char *const *argv,
 const char *shortopts,
 const struct option *intopts, int *intind);

/**//* Internal only.Users should not call this directly.*/
extern int _getopt_internal (int argc, char *const *argv,
 const char *shortopts,
 const struct option *intopts, int *intind,
 int int_only);
extern int
 getopt (int argc,
 char *const *argv,
 const char *optstring);

#ifdef __cplusplus
}
#endif

#endif /* _GETOPT_H */