Patch by Vasilis Kaoutsis: Implemented sigignore(). Small changes by myself.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22789 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/posix/signal.h

@@ -163,6 +163,7 @@ int     sigfillset(sigset_t *set);
 int 	sigaddset(sigset_t *set, int signo);
 int 	sigdelset(sigset_t *set, int signo);
 int 	sigismember(const sigset_t *set, int signo);
+int		sigignore(int signo);
 
 const char *strsignal(int sig);
 

src/system/libroot/posix/signal/Jamfile

@@ -10,6 +10,7 @@ MergeObject posix_signal.o :
 	set_signal_stack.c
 	sigaction.c
 	sigaltstack.c
+	sigignore.cpp
 	signal.c
 	sigpending.c
 	sigprocmask.c

src/system/libroot/posix/signal/sigignore.cpp

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2007, Vasilis Kaoutsis, kaoutsis@sch.gr
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <errno.h>
+#include <signal.h>
+
+#include <syscalls.h>
+
+
+int
+sigignore(int signal)
+{
+	// check for invalid signals or for signals
+	// that can not be ignored (SIGKILL, SIGSTOP)
+	if (signal <= 0 || signal >= NSIG || signal == SIGKILL
+		|| signal == SIGSTOP) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	struct sigaction ignoreSignalAction;
+		// create an action to ignore the signal
+
+	// request that the signal will be ignored
+	// by the handler of the action
+	ignoreSignalAction.sa_handler = SIG_IGN;
+	ignoreSignalAction.sa_flags = 0;
+
+	// In case of SIGCHLD the specification requires SA_NOCLDWAIT behavior.
+	if (signal == SIGCHLD)
+		ignoreSignalAction.sa_flags |= SA_NOCLDWAIT;
+
+	return sigaction(signal, &ignoreSignalAction, NULL);
+}