listamsb: don't try to read tokenized BASIC from a terminal.

1 files changed, 5 insertions, 0 deletions

diff --git a/listamsb.c b/listamsb.c
index d21623a..d84c3ab 100644
--- a/listamsb.c
+++ b/listamsb.c
@@ -220,6 +220,11 @@ void parse_args(int argc, char **argv) {
 	}
 
 	if(optind >= argc) {
+		if(isatty(fileno(stdin))) {
+			fprintf(stderr, "%s: can't read binary data from a terminal\n", self);
+			print_help();
+			exit(1);
+		}
 		freopen(NULL, "rb", stdin);
 		infile = stdin;
 	} else {