update the usage()

diff --git a/main.c b/main.c
index 198706d077fadb76ff789c43b7396e77966c1d58..9e27fbe026fa7562f2e459e7c0aee18ed26bcdd2 100644 (file)
--- a/main.c
+++ b/main.c
@@ -195,8 +195,8 @@ static void usage()
        printf("-s: show from the Nth sample\n");
        printf("-n: show when every N samples\n");
        printf("-I: show the internal circuit graph of IC number\n");
-       printf("-V: show the voltage of line numbers, v1 - v2 means the diff voltage between line 1 and line 2.\n");
-       printf("-A: show the current of components, i1 means the component with ID 1, i2c means the C pin of NPN or PNP with ID 2.\n");
+       printf("-V: save the voltage of lines      in 'v.txt', v1 - v2 means the diff voltage between line 1 and line 2.\n");
+       printf("-A: save the current of components in 'a.txt', i1 means the component with ID 1, i2c means the C pin of NPN or PNP with ID 2.\n");
        printf("src.cpk: electronic model file to simulate\n\n");
 }