revert to a single-header library

Author: lh3

ketopt.c

@@ -1,6 +1,8 @@
 #ifndef KETOPT_H
 #define KETOPT_H
 
+#include <string.h> /* for strchr() and strncmp() */
+
 #define ko_no_argument       0
 #define ko_required_argument 1
 #define ko_optional_argument 2
@@ -20,11 +22,16 @@ typedef struct {
 	int val;
 } ko_longopt_t;
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+static ketopt_t KETOPT_INIT = { 1, 0, 0, -1, 1, 0, 0 };
 
-extern ketopt_t KETOPT_INIT;
+static void ketopt_permute(char *argv[], int j, int n) /* move argv[j] over n elements to the left */
+{
+	int k;
+	char *p = argv[j];
+	for (k = 0; k < n; ++k)
+		argv[j - k] = argv[j - k - 1];
+	argv[j - k] = p;
+}
 
 /**
  * Parse command-line options and arguments
@@ -46,10 +53,64 @@ extern ketopt_t KETOPT_INIT;
  *         argv[] is fully processed; '?' for an unknown option or an ambiguous
  *         long option; ':' if an option argument is missing
  */
-int ketopt(ketopt_t *s, int argc, char *argv[], int permute, const char *ostr, const ko_longopt_t *longopts);
-
-#ifdef __cplusplus
+static int ketopt(ketopt_t *s, int argc, char *argv[], int permute, const char *ostr, const ko_longopt_t *longopts)
+{
+	int opt = -1, i0, j;
+	if (permute) {
+		while (s->i < argc && (argv[s->i][0] != '-' || argv[s->i][1] == '\0'))
+			++s->i, ++s->n_args;
+	}
+	s->arg = 0, s->longidx = -1, i0 = s->i;
+	if (s->i >= argc || argv[s->i][0] != '-' || argv[s->i][1] == '\0') {
+		s->ind = s->i - s->n_args;
+		return -1;
+	}
+	if (argv[s->i][0] == '-' && argv[s->i][1] == '-') { /* "--" or a long option */
+		if (argv[s->i][2] == '\0') { /* a bare "--" */
+			ketopt_permute(argv, s->i, s->n_args);
+			++s->i, s->ind = s->i - s->n_args;
+			return -1;
+		}
+		s->opt = 0, opt = '?', s->pos = -1;
+		if (longopts) { /* parse long options */
+			int k, n_matches = 0;
+			const ko_longopt_t *o = 0;
+			for (j = 2; argv[s->i][j] != '\0' && argv[s->i][j] != '='; ++j) {} /* find the end of the option name */
+			for (k = 0; longopts[k].name != 0; ++k)
+				if (strncmp(&argv[s->i][2], longopts[k].name, j - 2) == 0)
+					++n_matches, o = &longopts[k];
+			if (n_matches == 1) {
+				s->opt = opt = o->val, s->longidx = o - longopts;
+				if (argv[s->i][j] == '=') s->arg = &argv[s->i][j + 1];
+				if (o->has_arg == 1 && argv[s->i][j] == '\0') {
+					if (s->i < argc - 1) s->arg = argv[++s->i];
+					else opt = ':'; /* missing option argument */
+				}
+			}
+		}
+	} else { /* a short option */
+		char *p;
+		if (s->pos == 0) s->pos = 1;
+		opt = s->opt = argv[s->i][s->pos++];
+		p = strchr(ostr, opt);
+		if (p == 0) {
+			opt = '?'; /* unknown option */
+		} else if (p[1] == ':') {
+			if (argv[s->i][s->pos] == 0) {
+				if (s->i < argc - 1) s->arg = argv[++s->i];
+				else opt = ':'; /* missing option argument */
+			} else s->arg = &argv[s->i][s->pos];
+			s->pos = -1;
+		}
+	}
+	if (s->pos < 0 || argv[s->i][s->pos] == 0) {
+		++s->i, s->pos = 0;
+		if (s->n_args > 0) /* permute */
+			for (j = i0; j < s->i; ++j)
+				ketopt_permute(argv, j, s->n_args);
+	}
+	s->ind = s->i - s->n_args;
+	return opt;
 }
-#endif
 
 #endif

ketopt.h

@@ -62,5 +62,5 @@ kthread_test:kthread_test.c ../kthread.c
 kthread_test2:kthread_test2.c ../kthread.c
 		$(CC) $(CFLAGS) -o $@ kthread_test2.c ../kthread.c
 
-ketopt_test:ketopt_test.c ../ketopt.c
-		$(CC) $(CFLAGS) -o $@ ketopt_test.c ../ketopt.c
+ketopt_test:ketopt_test.c ../ketopt.h
+		$(CC) $(CFLAGS) -o $@ ketopt_test.c