--- rtcanrecv.c.orig	2011-06-27 12:02:43.634343171 -0400
+++ rtcanrecv.c	2011-06-27 12:12:32.834332555 -0400
@@ -24,6 +24,7 @@
 	    " -R, --timestamp-rel   with relative timestamp\n"
 	    " -v, --verbose         be verbose\n"
 	    " -p, --print=MODULO    print every MODULO message\n"
+	    " -L, --line-buffer     use line buffering\n"
 	    " -h, --help            this help\n",
 	    prg);
 }
@@ -31,7 +32,7 @@
 
 extern int optind, opterr, optopt;
 
-static int s = -1, verbose = 0, print = 1;
+static int s = -1, verbose = 0, print = 1, line_buffer = 0;
 static nanosecs_rel_t timeout = 0, with_timestamp = 0, timestamp_rel = 0;
 
 RT_TASK rt_task_desc;
@@ -174,6 +175,7 @@
 	{ "timeout", required_argument, 0, 't'},
 	{ "timestamp", no_argument, 0, 'T'},
 	{ "timestamp-rel", no_argument, 0, 'R'},
+	{ "line-buffer", no_argument, 0, 'L'},
 	{ 0, 0, 0, 0},
     };
 
@@ -182,7 +184,7 @@
     signal(SIGTERM, cleanup_and_exit);
     signal(SIGINT, cleanup_and_exit);
 
-    while ((opt = getopt_long(argc, argv, "hve:f:t:p:RT",
+    while ((opt = getopt_long(argc, argv, "hve:f:t:p:RTL",
 			      long_options, NULL)) != -1) {
 	switch (opt) {
 	case 'h':
@@ -230,6 +232,10 @@
 	    with_timestamp = 1;
 	    break;
 
+	case 'L':
+	    line_buffer = 1;
+	    break;
+
 	default:
 	    fprintf(stderr, "Unknown option %c\n", opt);
 	    break;
@@ -311,6 +317,10 @@
 	}
     }
 
+    if (line_buffer) {
+	setvbuf(stdout, NULL, _IOLBF, 0);
+    }
+
     snprintf(name, sizeof(name), "rtcanrecv-%d", getpid());
     ret = rt_task_shadow(&rt_task_desc, name, 0, 0);
     if (ret) {