Rotate log on SIGHUP

include/vapi/vapi_options.h

@@ -92,9 +92,7 @@
 	    " them. The file will be overwritten unless the -a option"	\
 	    " was specified. If the application receives a SIGHUP"	\
 	    " while writing to a file, it will reopen the file"		\
-	    " allowing the old one to be rotated away.\n"		\
-	    "\n"							\
-	    "XXX: Log rotation not yet implemented"			\
+	    " allowing the old one to be rotated away."			\
 	)
 
 #define VSL_OPT_x							\

lib/libvarnishtools/vut.c

@@ -259,6 +259,18 @@ VUT_Main(VSLQ_dispatch_f *func, void *priv)
 	}
 
 	while (!VUT.sigint) {
+		if (VUT.w_arg && VUT.sighup) {
+			/* Rotate log */
+			VUT.sighup = 0;
+			AN(VUT.fo);
+			fclose(VUT.fo);
+			VUT.fo = VSL_WriteOpen(VUT.vsl, VUT.w_arg, 0,
+			    VUT.u_opt);
+			if (VUT.fo == NULL)
+				VUT_Error(1, "Can't open output file (%s)",
+				    VSL_Error(VUT.vsl));
+		}
+
 		if (VUT.vslq == NULL) {
 			AZ(VUT.r_arg);
 			AN(VUT.vsm);