source: buchla-68k/orig/GP/GETOPT.C

/*
   =============================================================================
        getopt.c -- process the options on a Unix{tm} style command line
        Version 2 -- 1988-05-04 -- D.N. Lynx Crowe

        Adapted from public domain code by Henry Specner, et al,
        from Usenet "net.sources".

        extern int optind;      Index into nargv
        extern int opterr;      Error output flag
        extern int optopt;      Most recently parsed option letter
        extern char *optarg;    Pointer to option argument or NULL

        int
        getopt(nargc, nargv, optstr)
        int nargc;
        char *nargv[];
        char *optstr;

                Parses nargv[] according to optstr.  Returns the next
                option letter in argv that matches a letter in optstr.
                'optstr' is a string of recognized option letters;  if a
                letter is followed by a colon, the option is expected
                to have an argument that may or may not be separated
                from it by whitespace.  'optarg' is set to point to the
                start of the option argument on return from getopt.
                Assumes argv[0] is the program name.  Outputs error
                messages to stderr if 'opterr' is non-zero.  'optopt' is
                the most recently parsed option letter.

                Note:  this code is not ROM-able due to the use of an
                initialized static variable,  but this is probably not
                too important, as it's designed to be used as a command
                line processor.

        int
        getarg(nargc, nargv)
        int nargc;
        char *nargv[];

                Returns the index of the next argument, or EOF if the
                argument string is exhausted.  Used to get the file
                arguments after getopt() is finished.  Updates optarg
                to point at the argument.  Increments optind to point
                at the next argument.
   =============================================================================
*/

/* 

*/

#include "stdio.h"
#include "stddefs.h"

#define ARGCH           (int)':'
#define BADCH           (int)'?'
#define EMSG            ""
#define ENDARGS         "--"

int     opterr;         /* set to non-zero to get error message output */
int     optind;         /* index of current option string in parent argv */
int     optopt;         /* current option letter */

char    *optarg;        /* pointer to the option argument */

/* 

*/

int
getarg(nargc, nargv)
int nargc;
char *nargv[];
{
        if (optind EQ 0)                /* in case getopt() wasn't called */
                optind++;

        if (optind GE nargc)
                return(EOF);            /* out of arguments */

        optarg = nargv[optind];         /* set optarg to point at the argument */
        return(optind++);               /* return the argument index */
}

static
char *
index(s, c)
register char *s;
register int c;
{
        while (*s)
                if (c EQ *s)
                        return(s);
                else
                        s++;

        return(NULL);
}

/* 

*/

int
getopt(nargc, nargv, ostr)
int nargc;
char *nargv[], *ostr;
{
        static char *place = EMSG;      /* private scan pointer */
        register char *oli;

        if (optind EQ 0)        /* make sure optind starts out non-zero */
                ++optind;

        if (!*place) {          /* update the scan pointer */

                if ((optind GE nargc)
                    OR (*(place = nargv[optind]) NE '-')
                    OR (!*++place))
                        return(EOF);

                if (*place EQ '-') {            /* found "--" */

                        ++optind;
                        return(EOF);
                }
        }

        if (((optopt = (int)*place++) EQ ARGCH)
            OR (!(oli = index(ostr, optopt)))) {        /* option letter OK ? */

                if (!*place)
                        ++optind;

                if (opterr) {

                        fputs(*nargv, stderr);
                        fputs(": unknown argument \042", stderr);
                        fputc(optopt, stderr);
                        fputs("\042\n", stderr);
                }

                return(BADCH);
        }
/* 

*/
        if (*++oli NE ARGCH) {          /* check for required argument */

                optarg = NULL;          /* no argument needed */

                if (!*place)
                        ++optind;

        } else {        /* we need an arguement */

                if (*place)
                        optarg = place;
                else if (nargc LE ++optind) {

                        place = EMSG;

                        if (opterr) {

                                fputs(*nargv, stderr);
                                fputs(": option \042", stderr);
                                fputc(optopt, stderr);
                                fputs("\042 requires an argument.\n", stderr);
                        }

                        return(BADCH);

                } else
                        optarg = nargv[optind];

                place = EMSG;
                ++optind;
        }

        return(optopt);
}