1 files changed, 18 insertions, 0 deletions
diff --git a/src/libstddjb/sadirname.c b/src/libstddjb/sadirname.c
new file mode 100644
index 0000000..9fc4802
--- /dev/null
+++ b/src/libstddjb/sadirname.c
@@ -0,0 +1,18 @@
+/* ISC license. */
+
+#include <skalibs/bytestr.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+int sadirname (stralloc *sa, char const *s, unsigned int len)
+{
+  if (!len) return stralloc_catb(sa, ".", 1) ;
+  while (len && (s[len-1] == '/')) len-- ;
+  if (!len) return stralloc_catb(sa, "/", 1) ;
+  {
+    register unsigned int i = byte_rchr(s, len, '/') ;
+    return (i == len) ? stralloc_catb(sa, ".", 1) :
+           (i == 0)   ? stralloc_catb(sa, "/", 1) :
+                        stralloc_catb(sa, s, i) ;
+  }
+}