getopt.c
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/* ::[[ @(#) getopt.c 1.5 89/03/11 05:40:23 ]]:: */
#ifndef LINT
static const char Id[] = "$Id: getopt.c,v 1.1 2004/10/28 01:49:04 angel Exp $";
#endif
/*
* Here's something you've all been waiting for: the AT&T public domain
* source for getopt(3). It is the code which was given out at the 1985
* UNIFORUM conference in Dallas. I obtained it by electronic mail
* directly from AT&T. The people there assure me that it is indeed
* in the public domain.
*
* 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, and my source at AT&T did not send a copy.
* The current SVR2 man page reflects the actual behavor of this getopt.
* However, I am not about to post a copy of anything licensed by AT&T.
*/
#include <stdio.h>
#include <string.h>
#define ERR(szz,czz) if(opterr){fprintf(stderr,"%s%s%c\n",argv[0],szz,czz);}
int opterr = 1;
int optind = 1;
int optopt;
char *optarg;
int
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][1] == '\0')
return (EOF);
else if (strcmp(argv[optind], "--") == 0) {
optind++;
return (EOF);
}
}
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 ('?');
}
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 ('?');
} else
optarg = argv[optind++];
sp = 1;
} else {
if (argv[optind][++sp] == '\0') {
sp = 1;
optind++;
}
optarg = NULL;
}
return (c);
}