1 files changed, 45 insertions, 0 deletions
diff --git a/libc/signal/sigblock.c b/libc/signal/sigblock.c
new file mode 100644
index 000000000..8edfe0df2
--- /dev/null
+++ b/libc/signal/sigblock.c
@@ -0,0 +1,45 @@
+/* Copyright (C) 1991 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <errno.h>
+#define __USE_BSD
+#include <signal.h>
+
+/* Block signals in MASK, returning the old mask.  */
+int sigblock (int mask)
+{
+  register int sig;
+  sigset_t set, oset;
+
+  if (sigemptyset(&set) < 0)
+    return -1;
+  
+  for (sig = 1; sig < NSIG; ++sig)
+    if ((mask & sigmask(sig)) && sigaddset(&set, sig) < 0)
+      return -1;
+
+  if (sigprocmask(SIG_BLOCK, &set, &oset) < 0)
+    return -1;
+
+  mask = 0;
+  for (sig = 1; sig < NSIG; ++sig)
+    if (sigismember(&oset, sig))
+      mask |= sigmask(sig);
+
+  return mask;
+}