Clarify ROX.

[pintos-anon] / doc / userprog.texi

diff --git a/doc/userprog.texi b/doc/userprog.texi
index d401fda025f1f98b81ed78a31c743ccbd30bf68e..71b084ac3b02106877626dcbea6165112f193a3b 100644 (file)
--- a/doc/userprog.texi
+++ b/doc/userprog.texi
@@ -683,7 +683,8 @@ actual number written, or -1 if no bytes could be written at all.
 
 Fd 1 writes to the console.  Your code to write to the console should
 write all of @var{buffer} in one call to @func{putbuf}, at least as
-long as @var{size} is not bigger than a few hundred bytes.  Otherwise,
+long as @var{size} is not bigger than a few hundred bytes.  (It is
+reasonable to break up larger buffers.)  Otherwise,
 lines of text output by different processes may end up interleaved on
 the console, confusing both human readers and our grading scripts.
 
@@ -777,7 +778,8 @@ hurt even now.
 You can use @func{file_deny_write} to prevent writes to an open file.
 Calling @func{file_allow_write} on the file will re-enable them (unless
 the file is denied writes by another opener).  Closing a file will also
-re-enable writes.
+re-enable writes.  Thus, to deny writes to process's executable, you
+must keep it open as long as the process is still running.
 
 @node Project 2 FAQ
 @section FAQ