3 files changed, 76 insertions, 2 deletions

diff --git a/src/user/app/tests/libc/string.c b/src/user/app/tests/libc/string.c
index 53fe1c0..f865d72 100644
--- a/src/user/app/tests/libc/string.c
+++ b/src/user/app/tests/libc/string.c
@@ -65,9 +65,45 @@ static void test_strtol(void) {
 	test(!strcmp("hello", end));
 }
 
+static void test_strspn(void) {
+	test(0 == strspn("", "1234"));
+	test(0 == strspn("asdf", "1234"));
+	test(0 == strspn("a2df", "1234"));
+	test(2 == strspn("42df", "1234"));
+	test(4 == strspn("4211", "1234"));
+
+	test(0 == strcspn("", "1234"));
+	test(4 == strcspn("asdf", "1234"));
+	test(1 == strcspn("a2df", "1234"));
+}
+
+static void test_strtok(void) {
+	const char *sep = " \t";
+	{
+		char line[] = "LINE TO BE SEPARATED";
+		test(!strcmp(strtok(line, sep), "LINE"));
+		test(!strcmp(strtok(NULL, sep), "TO"));
+		test(!strcmp(strtok(NULL, sep), "BE"));
+		test(!strcmp(strtok(NULL, sep), "SEPARATED"));
+		for (int i = 0; i < 4; i++)
+			test(strtok(NULL, sep) == NULL);
+	}
+	{
+		char line[] = "  LINE TO\tBE  \t SEPARATED   ";
+		test(!strcmp(strtok(line, sep), "LINE"));
+		test(!strcmp(strtok(NULL, sep), "TO"));
+		test(!strcmp(strtok(NULL, sep), "BE"));
+		test(!strcmp(strtok(NULL, sep), "SEPARATED"));
+		for (int i = 0; i < 4; i++)
+			test(strtok(NULL, sep) == NULL);
+	}
+}
+
 void r_libc_string(void) {
 	run_test(test_memcmp);
 	run_test(test_memset);
 	run_test(test_strcmp);
 	run_test(test_strtol);
+	run_test(test_strspn);
+	run_test(test_strtok);
 }
diff --git a/src/user/lib/include/string.h b/src/user/lib/include/string.h
index eda4e48..5cddb61 100644
--- a/src/user/lib/include/string.h
+++ b/src/user/lib/include/string.h
@@ -3,3 +3,9 @@
 
 long strtol(const char *restrict s, char **restrict end, int base);
 char *strchr(const char *s, int c);
+
+size_t strspn(const char *s, const char *accept);
+size_t strcspn(const char *s, const char *reject);
+
+char *strtok(char *restrict s, const char *restrict sep);
+char *strtok_r(char *restrict s, const char *restrict sep, char **restrict state);
diff --git a/src/user/lib/string.c b/src/user/lib/string.c
index 9c347d0..ff67399 100644
--- a/src/user/lib/string.c
+++ b/src/user/lib/string.c
@@ -48,9 +48,41 @@ long strtol(const char *restrict s, char **restrict end, int base) {
 }
 
 char *strchr(const char *s, int c) {
-	while (*s) {
+	for (; *s; s++) {
 		if (*s == c) return (char*)s;
-		s++;
 	}
 	return NULL;
 }
+
+size_t strspn(const char *s, const char *accept) {
+	size_t l = 0;
+	for (; s[l] && strchr(accept, s[l]); l++);
+	return l;
+}
+
+size_t strcspn(const char *s, const char *reject) {
+	size_t l = 0;
+	for (; s[l] && !strchr(reject, s[l]); l++);
+	return l;
+}
+
+char *strtok(char *restrict s, const char *restrict sep) {
+	static char *state;
+	return strtok_r(s, sep, &state);
+}
+
+char *strtok_r(char *restrict s, const char *restrict sep, char **restrict state) {
+	char *end;
+	if (!s) s = *state;
+	s += strspn(s, sep); /* beginning of token */
+	if (!*s) return NULL;
+
+	end = s + strcspn(s, sep);
+	if (*end) {
+		*end = '\0';
+		*state = end + 1;
+	} else {
+		*state = end;
+	}
+	return s;
+}