usr: sdk: Add initial string lib sources + strlen

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/usr/sdk/common/string/strlen.c b/usr/sdk/common/string/strlen.c
new file mode 100644
index 0000000..4499512
--- /dev/null
+++ b/usr/sdk/common/string/strlen.c
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2025, Ian Moffett.
+ * Provided under the BSD-3 clause.
+ */
+
+#include <sdk/string.h>
+#include <sdk/types.h>
+
+USIZE
+strlen(const char *str)
+{
+    USIZE len = 0;
+
+    if (str == NULL) {
+        return 0;
+    }
+
+    while (str[len++] != '\0');
+    return len - 1;
+}