import the plan 9 libraries libc (lib9) and libbio into the tree.
remove the dependency on /home/r.
SVN=122482
diff --git a/src/lib9/rfork.c b/src/lib9/rfork.c
new file mode 100644
index 0000000..c9d6321
--- /dev/null
+++ b/src/lib9/rfork.c
@@ -0,0 +1,153 @@
+/*
+Plan 9 from User Space src/lib9/rfork.c
+http://code.swtch.com/plan9port/src/tip/src/lib9/rfork.c
+
+Copyright 2001-2007 Russ Cox. All Rights Reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include <u.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <libc.h>
+#undef rfork
+
+static void
+nop(int x)
+{
+ USED(x);
+}
+
+int
+p9rfork(int flags)
+{
+ int pid, status;
+ int p[2];
+ int n;
+ char buf[128], *q;
+ extern char **environ;
+
+ if((flags&(RFPROC|RFFDG|RFMEM)) == (RFPROC|RFFDG)){
+ /* check other flags before we commit */
+ flags &= ~(RFPROC|RFFDG|RFENVG);
+ n = (flags & ~(RFNOTEG|RFNAMEG|RFNOWAIT|RFCENVG));
+ if(n){
+ werrstr("unknown flags %08ux in rfork", n);
+ return -1;
+ }
+ if(flags&RFNOWAIT){
+ /*
+ * BUG - should put the signal handler back after we
+ * finish, but I just don't care. If a program calls with
+ * NOWAIT once, they're not likely to want child notes
+ * after that.
+ */
+ signal(SIGCHLD, nop);
+ if(pipe(p) < 0)
+ return -1;
+ }
+ pid = fork();
+ if(pid == -1)
+ return -1;
+ if(flags&RFNOWAIT){
+ flags &= ~RFNOWAIT;
+ if(pid){
+ /*
+ * Parent - wait for child to fork wait-free child.
+ * Then read pid from pipe. Assume pipe buffer can absorb the write.
+ */
+ close(p[1]);
+ status = 0;
+ if(wait4(pid, &status, 0, 0) < 0){
+ werrstr("pipe dance - wait4 - %r");
+ close(p[0]);
+ return -1;
+ }
+ n = readn(p[0], buf, sizeof buf-1);
+ close(p[0]);
+ if(!WIFEXITED(status) || WEXITSTATUS(status)!=0 || n <= 0){
+ if(!WIFEXITED(status))
+ werrstr("pipe dance - !exited 0x%ux", status);
+ else if(WEXITSTATUS(status) != 0)
+ werrstr("pipe dance - non-zero status 0x%ux", status);
+ else if(n < 0)
+ werrstr("pipe dance - pipe read error - %r");
+ else if(n == 0)
+ werrstr("pipe dance - pipe read eof");
+ else
+ werrstr("pipe dance - unknown failure");
+ return -1;
+ }
+ buf[n] = 0;
+ if(buf[0] == 'x'){
+ werrstr("%s", buf+2);
+ return -1;
+ }
+ pid = strtol(buf, &q, 0);
+ }else{
+ /*
+ * Child - fork a new child whose wait message can't
+ * get back to the parent because we're going to exit!
+ */
+ signal(SIGCHLD, SIG_IGN);
+ close(p[0]);
+ pid = fork();
+ if(pid){
+ /* Child parent - send status over pipe and exit. */
+ if(pid > 0)
+ fprint(p[1], "%d", pid);
+ else
+ fprint(p[1], "x %r");
+ close(p[1]);
+ _exit(0);
+ }else{
+ /* Child child - close pipe. */
+ close(p[1]);
+ }
+ }
+ }
+ if(pid != 0)
+ return pid;
+ if(flags&RFCENVG)
+ if(environ)
+ *environ = nil;
+ }
+ if(flags&RFPROC){
+ werrstr("cannot use rfork for shared memory -- use libthread");
+ return -1;
+ }
+ if(flags&RFNAMEG){
+ /* XXX set $NAMESPACE to a new directory */
+ flags &= ~RFNAMEG;
+ }
+ if(flags&RFNOTEG){
+ setpgid(0, getpid());
+ flags &= ~RFNOTEG;
+ }
+ if(flags&RFNOWAIT){
+ werrstr("cannot use RFNOWAIT without RFPROC");
+ return -1;
+ }
+ if(flags){
+ werrstr("unknown flags %08ux in rfork", flags);
+ return -1;
+ }
+ return 0;
+}
