--- /dev/null
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/*
+ * Calling signal() is non-portable, as it varies in meaning
+ * between platforms and depending on feature macros, and has
+ * stupid semantics at least some of the time.
+ *
+ * This function provides the same interface as the libc function,
+ * but provides consistent semantics. It assumes POSIX semantics
+ * for sigaction() (so you might need to do some more work if you
+ * port to something ancient like SunOS 4)
+ */
+void (*putty_signal(int sig, void (*func)(int)))(int) {
+ struct sigaction sa;
+ struct sigaction old;
+
+ sa.sa_handler = func;
+ if(sigemptyset(&sa.sa_mask) < 0)
+ return SIG_ERR;
+ sa.sa_flags = SA_RESTART;
+ if(sigaction(sig, &sa, &old) < 0)
+ return SIG_ERR;
+ return old.sa_handler;
+}
+
+void block_signal(int sig, int block_it)
+{
+ sigset_t ss;
+
+ sigemptyset(&ss);
+ sigaddset(&ss, sig);
+ if(sigprocmask(block_it ? SIG_BLOCK : SIG_UNBLOCK, &ss, 0) < 0) {
+ perror("sigprocmask");
+ exit(1);
+ }
+}
+
+/*
+Local Variables:
+c-basic-offset:4
+comment-column:40
+End:
+*/