In buildtoc, pull the sanity check for NUL bytes to the top level.

[perl5.git] / pod / perlfork.pod

diff --git a/pod/perlfork.pod b/pod/perlfork.pod
index 8ce0739..c09433f 100644 (file)
--- a/pod/perlfork.pod
+++ b/pod/perlfork.pod
@@ -95,12 +95,15 @@ manipulation functions applied to the ID returned by fork() will affect the
 waiting pseudo-process that called exec(), not the real process it is
 waiting for after the exec().
 
+When exec() is called inside a pseudo-process then DESTROY methods and
+END blocks will still be called after the external process returns.
+
 =item exit()
 
 exit() always exits just the executing pseudo-process, after automatically
 wait()-ing for any outstanding child pseudo-processes.  Note that this means
 that the process as a whole will not exit unless all running pseudo-processes
-have exited.
+have exited.  See below for some limitations with open filehandles.
 
 =item Open handles to files, directories and network sockets
 
@@ -177,6 +180,26 @@ the seek position in the parent will change it in the child and vice-versa.
 One can avoid this by opening files that need distinct seek pointers
 separately in the child.
 
+On some operating systems, notably Solaris and Unixware, calling C<exit()>
+from a child process will flush and close open filehandles in the parent,
+thereby corrupting the filehandles.  On these systems, calling C<_exit()>
+is suggested instead.  C<_exit()> is available in Perl through the 
+C<POSIX> module.  Please consult your system's manpages for more information
+on this.
+
+=item Open directory handles
+
+Perl will completely read from all open directory handles until they
+reach the end of the stream.  It will then seekdir() back to the
+original location and all future readdir() requests will be fulfilled
+from the cache buffer.  That means that neither directory handle held
+by the parent process nor the one held by the child process will see
+any changes made to the directory after the fork() call.
+
+Note that rewinddir() has a similar limitation on Windows and will not
+force readdir() to read the directory again either.  Only a newly
+opened directory handle will reflect changes to the directory.
+
 =item Forking pipe open() not yet implemented
 
 The C<open(FOO, "|-")> and C<open(BAR, "-|")> constructs are not yet
@@ -208,7 +231,6 @@ write to a forked child:
     else {
        # child
        while (<STDIN>) { print; }
-       close STDIN;
        exit(0);
     }
 
@@ -238,7 +260,6 @@ And this one reads from the child:
     else {
        # child
        print "pipe_from_fork\n";
-       close STDOUT;
        exit(0);
     }