1 files changed, 72 insertions, 0 deletions
diff --git a/ssh/string_view.c b/ssh/string_view.c
new file mode 100644
index 0000000..2f4f22a
--- /dev/null
+++ b/ssh/string_view.c
@@ -0,0 +1,72 @@
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include "string_view.h"
+
+
+struct string_view string_view(const char *s, size_t len) {
+	return (struct string_view){.s = s, .len = len};
+}
+
+bool sv_equals(const struct string_view s, const char *cmp) {
+	return s.s && s.len == strlen(cmp) && memcmp(s.s, cmp, s.len) == 0;
+}
+
+bool sv_is_empty(const struct string_view s) {
+	return !s.s || s.len == 0;
+}
+
+bool sv_copy(const struct string_view s, char **output) {
+	if (s.s != NULL) {
+		char *buffer = malloc(s.len + 1);
+		if (!buffer) return false;  // really should return TOMSG_ERR_MEMORY, but this will do
+		memcpy(buffer, s.s, s.len);
+		buffer[s.len] = '\0';
+		*output = buffer;
+		return true;
+	} else {
+		*output = NULL;
+		return false;
+	}
+}
+
+bool sv_parse_i64(const struct string_view s, int64_t *output) {
+	if (!s.s || s.len > 20) return false;  // strlen(itoa(INT64_MIN)) == 20
+	char buf[21];
+	memcpy(buf, s.s, s.len);
+	buf[s.len] = '\0';
+	char *endp;
+	*output = strtoll(buf, &endp, 10);
+	return endp == buf + s.len;
+}
+
+struct string_view sv_tokenise_word(struct string_view *line) {
+	if (!line->s) return string_view(NULL, 0);
+
+	for (size_t i = 0; i < line->len; i++) {
+		if (line->s[i] == ' ') {
+			const struct string_view word = string_view(line->s, i);
+			line->s += i + 1;
+			line->len -= i + 1;
+			return word;
+		}
+	}
+
+	// No space found; if line is not empty, this is the final word
+	if (line->len > 0) {
+		const struct string_view word = *line;
+		*line = string_view(NULL, 0);
+		return word;
+	}
+
+	// Line is empty, so return NULL.
+	return string_view(NULL, 0);
+}
+
+void sv_skip_whitespace(struct string_view *line) {
+	if (!line->s) return;
+	while (line->len > 0 && isspace(line->s[0])) {
+		line->s++;
+		line->len--;
+	}
+}