X-Git-Url: https://git.distorted.org.uk/~mdw/mLib-python/blobdiff_plain/a19eaede18c9176b382df01e4f6c6e5c04a87d0f..addc0c3760b565ead630bd67cc038b31954b9284:/mdup.pyx

diff --git a/mdup.pyx b/mdup.pyx
index cf3a3c0..7256211 100644
--- a/mdup.pyx
+++ b/mdup.pyx
@@ -24,6 +24,14 @@
 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 def mdup(v):
+  """
+  mdup(LIST) -> LIST:
+    LIST is a list (mutable sequence) of pairs (CUR, WANT).  Duplicate each
+    CUR file descriptor as WANT (may be -1 to mean `don't care'), closing
+    original CUR.  Works even if there are cycles.  LIST is updated in place
+    with CUR reflecting the new file descriptors even on error.  Returns the
+    same LIST on success.
+  """
   cdef mdup_fd *vv
   cdef size_t n
   cdef int i