Clarify that create and remove work on files, not on file descriptors.

[pintos-anon] / doc / userprog.texi

diff --git a/doc/userprog.texi b/doc/userprog.texi
index b50dc364829edcc186491b875e68e1b4cd470a72..75bc8e542ffd3772fd58b10808f8527b3aadbe36 100644 (file)
--- a/doc/userprog.texi
+++ b/doc/userprog.texi
@@ -619,10 +619,11 @@ the program cannot load or run for any reason.
 @end deftypefn
 
 @deftypefn {System Call} int wait (pid_t @var{pid})
-Waits for process @var{pid} to die and returns the status it passed to
-@code{exit}.  Returns -1 if @var{pid}
+If process @var{pid} is still alive, waits until it dies.
+Then, returns the status that @var{pid} passed to @code{exit},
+or -1 if @var{pid}
 was terminated by the kernel (e.g.@: killed due to an exception).  If
-@var{pid} is does not refer to a child of the
+@var{pid} does not refer to a child of the
 calling thread, or if @code{wait} has already been successfully
 called for the given @var{pid}, returns -1 immediately, without
 waiting.
@@ -654,11 +655,15 @@ of the rest.
 @deftypefn {System Call} bool create (const char *@var{file}, unsigned @var{initial_size})
 Creates a new file called @var{file} initially @var{initial_size} bytes
 in size.  Returns true if successful, false otherwise.
+Opening the new file is a separate operation using the @code{open}
+system call.
 @end deftypefn
 
 @deftypefn {System Call} bool remove (const char *@var{file})
 Deletes the file called @var{file}.  Returns true if successful, false
 otherwise.
+A file may be removed regardless of whether it is open or closed
+(@pxref{Removing an Open File}, for more information).
 @end deftypefn
 
 @deftypefn {System Call} int open (const char *@var{file})