Silly error with flock

[Robert Brown]

On the bottom of my copy of the flock manual page is the following:

     Unlike BSD flock(2), attempts to acquire an exclusive lock on an fd
     opened for reading but not writing will fail with EBADF, as will attempts
     to acquire a shared lock on a write-only fd.

Also, your test

      if ( lock <= 0) perror("open");

should be

      if ( lock < 0) perror("open");

but that's unrelated to the condition you asked about

Hope that helps!

Bob Brown
------------------------------------------------------------------
Silicon Graphics, Inc.  Advanced Systems Division