cat.c32: check if filename exists

Don't crash if the file doesn't exist.

Signed-off-by: Gert Hulselmans <gerth@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/com32/samples/cat.c b/com32/samples/cat.c
index 16380b0..3930f74 100644 (file)
--- a/com32/samples/cat.c
+++ b/com32/samples/cat.c
@@ -15,13 +15,18 @@ int main(int argc, char *argv[])
        printf("argv[%d] = %p = \"%s\"\n", i, argv[i], argv[i]);
 
     if (argc < 2) {
-       fprintf(stderr, "Missing file name!\n");
-       exit(1);
+       fprintf(stderr, "Usage: cat.c32 filename\n");
+       return 1;
     }
 
     printf("File = %s\n", argv[1]);
 
     f = fopen(argv[1], "r");
+    if (!f) {
+       fprintf(stderr, "File name \"%s\" does not exist.\n", argv[1]);
+       return 1;
+    }
+
     while ((ch = getc(f)) != EOF)
        putchar(ch);