Reorg unistd dir

1 files changed, 111 insertions, 0 deletions

diff --git a/libc/unistd/getopt.c b/libc/unistd/getopt.c
new file mode 100644
index 000000000..70d20b06b
--- /dev/null
+++ b/libc/unistd/getopt.c
@@ -0,0 +1,111 @@
+
+/*
+ * From: gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) Newsgroups: net.sources
+ * Subject: getopt library routine Date: 30 Mar 85 04:45:33 GMT
+ */
+/*
+ * getopt -- public domain version of standard System V routine
+ * 
+ * Strictly enforces the System V Command Syntax Standard; provided by D A
+ * Gwyn of BRL for generic ANSI C implementations
+ * 
+ * #define STRICT to prevent acceptance of clustered options with arguments
+ * and ommision of whitespace between option and arg.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+int opterr = 1;					/* error => print message */
+int optind = 1;					/* next argv[] index */
+int optopt = 1;					/* Set for unknown arguments */
+char *optarg = NULL;			/* option parameter if any */
+
+static int Err(name, mess, c) /* returns '?' */
+char *name;						/* program name argv[0] */
+char *mess;						/* specific message */
+int c;							/* defective option letter */
+{
+	optopt = c;
+	if (opterr) {
+		(void) fprintf(stderr, "%s: %s -- %c\n", name, mess, c);
+	}
+
+	return '?';					/* erroneous-option marker */
+}
+
+int getopt(argc, argv, optstring) /* returns letter, '?', EOF */
+int argc;						/* argument count from main */
+char *argv[];					/* argument vector from main */
+char *optstring;				/* allowed args, e.g. "ab:c" */
+{
+	static int sp = 1;			/* position within argument */
+	register int osp;			/* saved `sp' for param test */
+
+#ifndef STRICT
+	register int oind;			/* saved `optind' for param test */
+#endif
+	register int c;				/* option letter */
+	register char *cp;			/* -> option in `optstring' */
+
+	optarg = NULL;
+
+	if (sp == 1) {				/* fresh argument */
+		if (optind >= argc		/* no more arguments */
+			|| argv[optind][0] != '-'	/* no more options */
+			|| argv[optind][1] == '\0'	/* not option; stdin */
+			)
+			return EOF;
+		else if (strcmp(argv[optind], "--") == 0) {
+			++optind;			/* skip over "--" */
+			return EOF;			/* "--" marks end of options */
+		}
+	}
+
+	c = argv[optind][sp];		/* option letter */
+	osp = sp++;					/* get ready for next letter */
+
+#ifndef STRICT
+	oind = optind;				/* save optind for param test */
+#endif
+	if (argv[optind][sp] == '\0') {	/* end of argument */
+		++optind;				/* get ready for next try */
+		sp = 1;					/* beginning of next argument */
+	}
+
+	if (c == ':' || c == '?'	/* optstring syntax conflict */
+		|| (cp = strchr(optstring, c)) == NULL /* not found */ ) {
+		return Err(argv[0], "illegal option", c);
+	}
+
+	if (cp[1] == ':') {			/* option takes parameter */
+#ifdef STRICT
+		if (osp != 1) {
+			return Err(argv[0], "option must not be clustered", c);
+		}
+
+		/* reset by end of argument */
+		if (sp != 1) {
+			return Err(argv[0], "option must be followed by white space",
+					   c);
+		}
+#else
+		if (oind == optind) {	/* argument w/o whitespace */
+			optarg = &argv[optind][sp];
+			sp = 1;				/* beginning of next argument */
+		}
+
+		else
+#endif
+		if (optind >= argc) {
+			return Err(argv[0], "option requires an argument", c);
+		}
+
+		else					/* argument w/ whitespace */
+			optarg = argv[optind];
+
+		++optind;				/* skip over parameter */
+	}
+
+	return c;
+}