1 files changed, 30 insertions, 0 deletions
diff --git a/lib/PublicInbox/CmdIPC1.pm b/lib/PublicInbox/CmdIPC1.pm
new file mode 100644
index 00000000..0eed8bed
--- /dev/null
+++ b/lib/PublicInbox/CmdIPC1.pm
@@ -0,0 +1,30 @@
+# Copyright (C) 2021 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# callers should use PublicInbox::CmdIPC1->can('send_cmd1') (or recv_cmd1)
+# 2nd choice for lei(1) front-end and 3rd choice for lei internals
+package PublicInbox::CmdIPC1;
+use strict;
+use v5.10.1;
+BEGIN { eval {
+require IO::FDPass; # XS, available in all major distros
+no warnings 'once';
+
+*send_cmd1 = sub ($$$$$$) { # (sock, in, out, err, buf, flags) = @_;
+        for (1..3) {
+                IO::FDPass::send(fileno($_[0]), $_[$_]) or
+                                        die "IO::FDPass::send: $!";
+        }
+        send($_[0], $_[4], $_[5]) or die "send $!";
+};
+
+*recv_cmd1 = sub ($$$) {
+        my ($s, undef, $len) = @_;
+        my @fds = map { IO::FDPass::recv(fileno($s)) } (0..2);
+        recv($s, $_[1], $len, 0) // die "recv: $!";
+        length($_[1]) == 0 ? () : @fds;
+};
+
+} } # /eval /BEGIN
+
+1;