New APIs: set-pgroup, get-pgroup

If the pgroup flag is set in the handle, then the qemu and recovery
subprocesses are placed in separate process groups.  The default is
false.

The purpose for setting up a process group is that ^C will not be
passed from the main process down to these processes (killing them).
This allows ^C and other keyboard events to be caught and handled in
the main process.

1 files changed, 19 insertions, 0 deletions

diff --git a/generator/generator_actions.ml b/generator/generator_actions.ml
index 1ccacdb8..87c934aa 100644
--- a/generator/generator_actions.ml
+++ b/generator/generator_actions.ml
@@ -1526,6 +1526,25 @@ advice before using trademarks in applications.
 
 =back");
 
+  ("set_pgroup", (RErr, [Bool "pgroup"], []), -1, [FishAlias "pgroup"],
+   [],
+   "set process group flag",
+   "\
+If C<pgroup> is true, child processes are placed into
+their own process group.
+
+The practical upshot of this is that signals like C<SIGINT> (from
+users pressing C<^C>) won't be received by the child process.
+
+The default for this flag is false, because usually you want
+C<^C> to kill the subprocess.");
+
+  ("get_pgroup", (RBool "pgroup", [], []), -1, [],
+   [],
+   "get process group flag",
+   "\
+This returns the process group flag.");
+
 ]
 
 (* daemon_functions are any functions which cause some action