getopt.c

md5验证的源代码 编译后可以直接使用

/*
   **   @(#)getopt.c    2.5 (smail) 9/15/87
 */

/*
   *  This is the AT&T public domain source for getopt(3).  It is the code
   *  which was given out at the 1985 UNIFORUM conference in Dallas.
   *   
   *  There is no manual page.  That is because the one they gave out at
   *  UNIFORUM was slightly different from the current System V Release 2
   *  manual page.  The difference apparently involved a note about the
   *  famous rules 5 and 6, recommending using white space between an
   *  option and its first argument, and not grouping options that have
   *  arguments.  Getopt itself is currently lenient about both of these
   *  things.  White space is allowed, but not mandatory, and the last option
   *  in a group can have an argument.  That particular version of the man
   *  page evidently has no official existence.  The current SVR2 man page
   *  reflects the actual behavor of this getopt.
 */

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

/*LINTLIBRARY */
#ifndef NULL
#define NULL	0
#endif
#define EOF	(-1)
#define ERR(str, chr) (opterr ? \
fprintf(stderr, "%s%s%c\n", argv[0], str, chr) : 0)

int opterr = 1;
int optind = 1;
int optopt = 0;
char *optarg = 0;

int pgp_getopt(int argc, char **argv, char *opts)
{
    static int sp = 1;
    register int c;
    register char *cp;

    if (sp == 1) {
	if (optind >= argc || (argv[optind][0] != '+' &&
		      argv[optind][0] != '-') || argv[optind][1] == '\0')
	    return EOF;
	else if (strcmp(argv[optind], "--") == 0) {
	    optind++;
	    return EOF;
	}
	/* '+' for config options, '+' should not be in the opts list */
	if (argv[optind][0] == '+') {
	    optarg = argv[optind++] + 1;
	    return '+';
	}
    }
    optopt = c = argv[optind][sp];
    if (c == ':' || (cp = strchr(opts, c)) == NULL) {
	ERR(": illegal option -- ", c);
	if (argv[optind][++sp] == '\0') {
	    optind++;
	    sp = 1;
	}
	return '\0';
    }
    if (*++cp == ':') {
	if (argv[optind][sp + 1] != '\0')
	    optarg = &argv[optind++][sp + 1];
	else if (++optind >= argc) {
	    ERR(": option requires an argument -- ", c);
	    sp = 1;
	    return '\0';
	} else
	    optarg = argv[optind++];
	sp = 1;
    } else {
	if (argv[optind][++sp] == '\0') {
	    sp = 1;
	    optind++;
	}
	optarg = NULL;
    }
    return c;
}