Improve documentation of readv_nonblock().

Define the meaning of "sz".

diff --git a/fd.c b/fd.c
index 3a8406d9c9fd1454a0807c8584bae78aa1b2f543..133f5d3baef49a0d600c4fd0f03ac2b20692631b 100644 (file)
--- a/fd.c
+++ b/fd.c
@@ -162,9 +162,9 @@ __printf_2_3 int write_va_buffer(int fd, const char *fmt, ...)
  *
  * If \a rfds is not \p NULL and the (non-blocking) file descriptor \a fd is
  * not set in \a rfds, this function returns early without doing anything.
- * Otherwise The function tries to read up to \a sz bytes from \a fd. As for
- * xwrite(), EAGAIN is not considered an error condition. However, EOF
- * is.
+ * Otherwise The function tries to read up to \a sz bytes from \a fd, where \a
+ * sz is the sum of the lengths of all vectors in \a iov. As for xwrite(),
+ * \p EAGAIN is not considered an error condition. However, \p EOF is.
  *
  * \return Zero or a negative error code. If the underlying call to readv(2)
  * returned zero (indicating an end of file condition) or failed for some