Category : C Source Code
Archive   : SNIP1292.ZIP
Filename : GETOPT3.C

/*
* * @(#)getopt.c 2.3 (smail) 5/30/87
*/

/*
* 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.
*/

#ifdef BSD
#include
#else
#define index strchr
#include
#endif

/* LINTLIBRARY */

#define NULL 0
#define EOF (-1)
#define ERR(s, c) if(opterr){\
extern int write();\
char errbuf[2];\
errbuf[0] = c; errbuf[1] = '\n';\
(void) write(2, strlwr(argv[0]), (unsigned)strlen(argv[0]));\
(void) write(2, s, (unsigned)strlen(s));\
(void) write(2, errbuf, 2);}

extern char *index();

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], "--") == NULL)
{
optind++;
return (EOF);
}
}
optopt = c = argv[optind][sp];
if (c == ':' || (cp = index(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);
}