Constrain the options so that -M cannot be used with -U (as it is a different action) and -M will report the right error message if mixed with -R or -Q (#67).

docs/pv.1

@@ -439,6 +439,8 @@ the latter can't show the input:output ratio.
 The values \*(lq\fB0\fR\*(rq, \*(lq\fB1\fR\*(rq, and \*(lq\fB2\fR\*(rq may
 be used as synonyms for \*(lq\fBin\fR\*(rq, \*(lq\fBout\fR\*(rq, and
 \*(lq\fBboth\fR\*(rq.
+.IP
+This option cannot be used with \*(lq\fB\-\-store\-and\-forward\*(rq.
 .\"TODO: formatting option for input:output ratio
 .\"
 .SS "Other options"

src/include/options.h

@@ -40,6 +40,7 @@ typedef enum {
  * Sides of a monitored command to monitor with PV_ACTION_MONITOR.
  */
 typedef enum {
+	PV_SIDE_NONE,			/* don't monitor a command */
 	PV_SIDE_IN,			/* monitor only the input side */
 	PV_SIDE_OUT,			/* monitor only the output side */
 	PV_SIDE_BOTH			/* monitor both sides */

src/main/options.c

@@ -762,6 +762,7 @@ opts_t opts_parse(unsigned int argc, char **argv)
 	numopts = 0;
 
 	opts->action = PV_ACTION_TRANSFER;
+	opts->side = PV_SIDE_NONE;
 	opts->interval = 1;
 	opts->delay_start = 0;
 	opts->average_rate_window = 30;
@@ -1293,6 +1294,31 @@ opts_t opts_parse(unsigned int argc, char **argv)
 	if (opts->error_skip_block > 0 && 0 == opts->skip_errors)
 		opts->skip_errors = 1;
 
+	/*
+	 * Don't allow -R or -Q with -M.
+	 */
+	if ((PV_ACTION_MONITOR == opts->action) && ((0 != opts->remote) || (0 != opts->query))) {
+		/*@-mustfreefresh@ *//* see above */
+		fprintf(stderr, "%s: %s: %s\n", opts->program_name, 0 != opts->remote ? "-R" : "-Q",
+			_("monitor mode cannot be specified with this option"));
+		opts_free(opts);
+		return NULL;
+		/*@+mustfreefresh@ */
+	}
+
+	/*
+	 * Don't allow -U with -M.
+	 */
+	if ((PV_ACTION_STORE_AND_FORWARD == opts->action && PV_SIDE_NONE != opts->side)
+	    || (PV_ACTION_MONITOR == opts->action && NULL != opts->store_and_forward_file)) {
+		/*@-mustfreefresh@ *//* see above */
+		fprintf(stderr, "%s: %s\n", opts->program_name,
+			_("monitor mode cannot be used with store-and-forward"));
+		opts_free(opts);
+		return NULL;
+		/*@+mustfreefresh@ */
+	}
+
 	/*
 	 * Don't allow any non-option arguments with -R or -Q.
 	 */