1 files changed, 14 insertions, 0 deletions
diff --git a/userland/libc/string/strcspn.c b/userland/libc/string/strcspn.c
new file mode 100644
index 0000000..2ad38d5
--- /dev/null
+++ b/userland/libc/string/strcspn.c
@@ -0,0 +1,14 @@
+#include <string.h>
+
+size_t strcspn(const char *s1, const char *s2) {
+  size_t r = 0;
+  for (; *s1; s1++) {
+    for (const char *t = s2; *t; t++) {
+      if (*s1 == *s2) {
+        r++;
+	break;
+      }
+    }
+  }
+  return r;
+}