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+/*
+ * * @(#)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 behavior of this getopt. However, I am not about to
+ * post a copy of anything licensed by AT&T.
+ */
+
+#ifdef BSD
+ #include <strings.h>
+#else
+ #define index strchr
+ #include <string.h>
+#endif
+
+/* LINTLIBRARY */
+#ifndef NULL
+#define NULL 0
+#endif
+
+#define EOF (-1)
+#define ERR(s, c) if(opterr){\
+ extern int write(int, void *, unsigned);\
+ char errbuf[2];\
+ errbuf[0] = (char)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], "--") == 0)
+ {
+ 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);
+}