add public domain getopt(3)

libraries/liblutil/getopt.c

+/*
+	getopt.c
+
+	modified public-domain AT&T getopt(3)
+*/
+
+#include <stdio.h>
+#include <string.h>
+
+#ifdef _POSIX_SOURCE
+#	include <unistd.h>
+#else
+#	define STDERR_FILENO 2
+#	ifdef __STDC__
+		extern int write (int fildes, char * buf, unsigned nbyte);
+#	else
+		extern int write ();
+#	endif
+#endif
+
+int opterr = 1;
+int optind = 1;
+int optopt;
+char * optarg;
+
+#ifdef __STDC__
+	static void ERR (char ** argv, char * s, char c)
+#else
+	static void ERR (argv, s, c)
+	char ** argv, * s, c;
+#endif
+{
+	char errbuf[2];
+
+#ifdef DF_TRACE_DEBUG
+printf("DF_TRACE_DEBUG: 	static void ERR () in getopt.c\n");
+#endif
+	if (opterr)
+	{
+		errbuf[0] = c;
+		errbuf[1] = '\n';
+		(void) write(STDERR_FILENO,argv[0],strlen(argv[0]));
+		(void) write(STDERR_FILENO,s,strlen(s));
+		(void) write(STDERR_FILENO,errbuf,sizeof errbuf);
+	}
+}
+
+#ifdef __STDC__
+	int getopt (int argc, char ** argv, char * opts)
+#else
+	int getopt (argc, argv, opts)
+	int argc;
+	char ** argv, * opts;
+#endif
+{
+	static int sp = 1, error = (int) '?';
+	static char sw = '-', eos = '\0', arg = ':';
+	register char c, * cp;
+
+#ifdef DF_TRACE_DEBUG
+printf("DF_TRACE_DEBUG: 	int getopt () in getopt.c\n");
+#endif
+	if (sp == 1)
+		if (optind >= argc || argv[optind][0] != sw
+		|| argv[optind][1] == eos)
+			return EOF;
+		else if (strcmp(argv[optind],"--") == 0)
+		{
+			optind++;
+			return EOF;
+		}
+	c = argv[optind][sp];
+	optopt = (int) c;
+	if (c == arg || (cp = strchr(opts,c)) == NULL)
+	{
+		ERR(argv,": illegal option--",c);
+		if (argv[optind][++sp] == eos)
+		{
+			optind++;
+			sp = 1;
+		}
+		return error;
+	}
+	else if (*++cp == arg)
+	{
+		if (argv[optind][sp + 1] != eos)
+			optarg = &argv[optind++][sp + 1];
+		else if (++optind >= argc)
+		{
+			ERR(argv,": option requires an argument--",c);
+			sp = 1;
+			return error;
+		}
+		else
+			optarg = argv[optind++];
+		sp = 1;
+	}
+	else
+	{
+		if (argv[optind][++sp] == eos)
+		{
+			sp = 1;
+			optind++;
+		}
+		optarg = NULL;
+	}
+	return (int) c;
+}