getopt.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "getopt.h"

Go to the source code of this file.

Macros
#define	BADCH   (int)'?'
#define	BADARG   (int)':'
#define	EMSG   ""

Functions
int	getopt (int nargc, char *const *nargv, const char *ostr)

Variables
int	opterr = 1
int	optind = 1
int	optopt
int	optreset
char *	optarg

Macro Definition Documentation

BADARG

#define BADARG   (int)':'

Definition at line 51 of file getopt.c.

BADCH

#define BADCH   (int)'?'

Definition at line 50 of file getopt.c.

EMSG

#define EMSG   ""

Definition at line 52 of file getopt.c.

Function Documentation

getopt()

int getopt	(	int	nargc,
		char *const *	nargv,
		const char *	ostr
	)

Definition at line 59 of file getopt.c.

                                                        {
    static char *place = EMSG; /* option letter processing */
    char *oli;                 /* option letter list index */
 
    if (optreset || !*place) { /* update scanning pointer */
        optreset = 0;
        if (optind >= nargc || *(place = nargv[optind]) != '-') {
            place = EMSG;
            return (EOF);
        }
        if (place[1] && *++place == '-') { /* found "--" */
            ++optind;
            place = EMSG;
            return (EOF);
        }
    } /* option letter okay? */
    if ((optopt = (int)*place++) == (int)':' || !(oli = (char *)strchr(ostr, optopt))) {
        /*
         * if the user didn't specify '-' as an option,
         * assume it means EOF.
         */
        if (optopt == (int)'-')
            return (EOF);
        if (!*place)
            ++optind;
        if (opterr && *ostr != ':')
            (void)fprintf(stderr, "illegal option -- %c\n", optopt);
        return (BADCH);
    }
    if (*++oli != ':') { /* don't need argument */
        optarg = NULL;
        if (!*place)
            ++optind;
    }
    else {          /* need an argument */
        if (*place) /* no white space */
            optarg = place;
        else if (nargc <= ++optind) { /* no arg */
            place = EMSG;
            if (*ostr == ':')
                return (BADARG);
            if (opterr)
                (void)fprintf(stderr, "option requires an argument -- %c\n", optopt);
            return (BADCH);
        }
        else /* white space */
            optarg = nargv[optind];
        place = EMSG;
        ++optind;
    }
    return (optopt); /* dump back option letter */
}

References BADARG, BADCH, EMSG, NULL, optarg, opterr, optind, optopt, and optreset.

Variable Documentation

optarg

char* optarg

Definition at line 48 of file getopt.c.

opterr

int opterr = 1

Definition at line 44 of file getopt.c.

optind

int optind = 1

Definition at line 45 of file getopt.c.

optopt

int optopt

Definition at line 46 of file getopt.c.

optreset

int optreset

Definition at line 47 of file getopt.c.

Referenced by getopt().