1 files changed, 36 insertions, 0 deletions
diff --git a/src/libstddjb/str_strn.c b/src/libstddjb/str_strn.c
new file mode 100644
index 0000000..7c2e425
--- /dev/null
+++ b/src/libstddjb/str_strn.c
@@ -0,0 +1,36 @@
+/* ISC license. */
+
+#include <skalibs/config.h>
+#include <skalibs/bytestr.h>
+
+#ifdef SKALIBS_FLAG_REPLACE_LIBC
+
+/* Very naive implementation, but it's small. */
+
+unsigned int str_strn (char const *haystack, unsigned int hlen, char const *needle, unsigned int nlen)
+{
+  register unsigned int i = 0 ;
+  if (!nlen) return 0 ;
+  if (hlen < nlen) return hlen ;
+  hlen -= nlen ;
+  for (; i <= hlen ; i++)
+    if (!byte_diff(haystack+i, nlen, needle)) return i ;
+  return hlen+nlen ;
+}
+
+#else
+
+#include <string.h>
+
+unsigned int str_strn (char const *haystack, unsigned int hlen, char const *needle, unsigned int nlen)
+{
+  char haystack2[hlen+1] ;
+  char needle2[nlen+1] ;
+  register char *p ;
+  byte_copy(haystack2, hlen, haystack) ; haystack2[hlen] = 0 ;
+  byte_copy(needle2, nlen, needle) ; needle2[nlen] = 0 ;
+  p = strstr(haystack2, needle2) ;
+  return p ? p - haystack2 : hlen ;
+}
+
+#endif