Added the Boost Jam execcmd.c module that got skipped by accident in revision 79055.

[SVN r79057]

src/engine/execcmd.c

@@ -0,0 +1,33 @@
+/*
+ * Copyright 1993, 1995 Christopher Seiwald.
+ * Copyright 2007 Noel Belcourt.
+ *
+ *   Utility functions shared between different exec*.c platform specific
+ * implementation modules.
+ *
+ * This file is part of Jam - see jam.c for Copyright information.
+ */
+
+#include "jam.h"
+#include "execcmd.h"
+
+
+/* Internal interrupt counter. */
+static int intr;
+
+
+/* Returns whether an interrupt has been detected so far. */
+
+int interrupted( void )
+{
+    return intr != 0;
+}
+
+
+/* Internal interrupt handler. */
+
+void onintr( int disp )
+{
+    ++intr;
+    printf( "...interrupted\n" );
+}