1 files changed, 30 insertions, 0 deletions
diff --git a/unix/utils/signal.c b/unix/utils/signal.c
new file mode 100644
index 00000000..a56fe6be
--- /dev/null
+++ b/unix/utils/signal.c
@@ -0,0 +1,30 @@
+/*
+ * PuTTY's wrapper on signal(2).
+ *
+ * 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).
+ */
+
+#include <signal.h>
+
+#include "defs.h"
+
+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;
+}