1 files changed, 17 insertions, 7 deletions
diff --git a/src/user/knob/block.c b/src/user/knob/block.c
index 9f3f353..8b9971f 100644
--- a/src/user/knob/block.c
+++ b/src/user/knob/block.c
@@ -1,4 +1,5 @@
 #include <knob/panic.h>
+#include <knob/block.h>
 #include <knob/heap.h>
 #include <stdbool.h>
 #include <stdint.h>
@@ -28,13 +29,22 @@ uint32_t strcpy(char *to, const char *from) {
 }
 
 char *strdup(const char *from) {
-  const char *end = from;
-  while (*(end++))
-    ;
-  char *buf = get_block(end - from);
-  if (!buf)
-    PANIC("get_block returned 0 in strdup");
-  blockcpy(buf, from, end - from);
+  const uint32_t len = strlen(from) + 1;
+  char *buf = get_block(len);
+  blockcpy(buf, from, len);
+  return buf;
+}
+
+char *strndup(const char *from, uint32_t n) {
+  uint32_t len = strlen(from) + 1;
+  if (n < len) {
+    char *buf = get_block(n + 1);
+    blockcpy(buf, from, n);
+    buf[n] = '\0';
+    return buf;
+  }
+  char *buf = get_block(len);
+  blockcpy(buf, from, len);
   return buf;
 }