Research V3 development

Work on file man/man2/wait.2

Co-Authored-By: Dennis Ritchie <dmr@research.uucp>
Synthesized-from: v3

diff --git a/man/man2/wait.2 b/man/man2/wait.2
new file mode 100644 (file)
index 0000000..1c76ef1
--- /dev/null
+++ b/man/man2/wait.2
@@ -0,0 +1,59 @@
+.pa 1
+.he 'WAIT (II)'9/4/72'WAIT (II)'
+.ti 0
+NAME           wait  --  wait for process to die
+.sp
+.ti 0
+SYNOPSIS       sys wait  / wait = 7.
+.br
+(process ID in r0)
+.br
+(termination status/user status in r1)
+.sp
+.ti 0
+DESCRIPTION    wait\b\b\b\b____
+causes its caller to delay until one of its child
+processes terminates.
+If any child has died since the last wait\b\b\b\b____, return is immediate;
+if there are no children, return is immediate with
+the error bit set.
+In the case of several children several wait\b\b\b\b____s are needed
+to learn of all the deaths.
+.sp
+If the error bit is not set on return,
+the r1 high byte contains the low byte of the
+child process r0 when it terminated.
+The r1 low byte contains the termination status
+of the process from the following list:
+.sp
+   0   exit
+   1   bus error
+   2   illegal instruction
+   3   trace trap
+   4   IOT trap
+   5   power fail trap
+   6   EMT trap
+   7   bad system call
+   8   PIR interrupt
+   9   floating point exception
+  10   memory violation
+  11   quit
+  12   interrupt
+  13   kill (see kill(II))
+  14   User I/O (not currently possible)
+ +16   core image produced
+.sp
+.ti 0
+SEE ALSO       exit(II), fork(II)
+.sp
+.ti 0
+DIAGNOSTICS    error bit
+(c-bit) on if no children not previously waited for.
+.sp
+.ti 0
+BUGS           A child
+which dies, but is never
+waited for consumes
+a slot in the process table.
+When this table is full,
+the system is effectively hung.