Added "--discard" option.

src/main/help.c

@@ -377,6 +377,9 @@ void display_help(void)
 		{ "-K", "--direct-io", NULL,
 		 N_("use direct I/O to bypass cache"),
 		 { 0, 0, 0, 0} },
+		{ "-X", "--discard", NULL,
+		 N_("discard input instead of writing to output"),
+		 { 0, 0, 0, 0} },
 #ifdef HAVE_IPC
 		{ "-R", "--remote", N_("PID"),
 		 N_("update settings of process PID"),

src/main/main.c

@@ -273,6 +273,7 @@ int main(int argc, char **argv)
 	pv_state_stop_at_size_set(state, opts->stop_at_size);
 	pv_state_sync_after_write_set(state, opts->sync_after_write);
 	pv_state_direct_io_set(state, opts->direct_io);
+	pv_state_discard_input_set(state, opts->discard_input);
 	pv_state_rate_limit_set(state, opts->rate_limit);
 	pv_state_target_buffer_size_set(state, opts->buffer_size);
 	pv_state_no_splice_set(state, opts->no_splice);

src/main/options.c

@@ -172,6 +172,7 @@ opts_t opts_parse(unsigned int argc, char **argv)
 		{ "stop-at-size", 0, NULL, (int) 'S' },
 		{ "sync", 0, NULL, (int) 'Y' },
 		{ "direct-io", 0, NULL, (int) 'K' },
+		{ "discard", 0, NULL, (int) 'X' },
 		{ "remote", 1, NULL, (int) 'R' },
 		{ "pidfile", 1, NULL, (int) 'P' },
 		{ "watchfd", 1, NULL, (int) 'd' },
@@ -184,7 +185,7 @@ opts_t opts_parse(unsigned int argc, char **argv)
 	/*@+nullassign@ */
 	int option_index = 0;
 #endif				/* HAVE_GETOPT_LONG */
-	char *short_options = "hVpteIrab8TA:fnqcWD:s:l0i:w:H:N:F:L:B:CESYKR:P:d:m:"
+	char *short_options = "hVpteIrab8TA:fnqcWD:s:l0i:w:H:N:F:L:B:CESYKXR:P:d:m:"
 #ifdef ENABLE_DEBUGGING
 	    "!:"
 #endif
@@ -464,6 +465,10 @@ opts_t opts_parse(unsigned int argc, char **argv)
 		case 'K':
 			opts->direct_io = true;
 			break;
+		case 'X':
+			opts->discard_input = true;
+			opts->no_splice = true;
+			break;
 		case 'R':
 			opts->remote = pv_getnum_ui(optarg);
 			break;