fairland: Check positional arguments more thoroughly

fairland silently "corrects" some bad arguments.  Reject them instead.
It neglects to check others completely.  Fix that.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

diff --git a/src/util/fairland.c b/src/util/fairland.c
index 4f772eaf7b50b34b82f9a2fc672963d98db5d389..12349880a44bc43d198a3978d75850e9785198e3 100644 (file)
--- a/src/util/fairland.c
+++ b/src/util/fairland.c
@@ -407,26 +407,43 @@ parse_args(int argc, char *argv[])
        ni = atoi(argv[2]);
     else
        ni = nc;
+    if (ni < 0) {
+       fprintf(stderr, "%s: number of islands must be >= 0\n",
+               program_name);
+       exit(1);
+    }
 
     if (argc > 3)
        is = atoi(argv[3]);
     else
        is = sc / 2;
-    if (is < 1)
-       is = 1;
+    if (is < 1) {
+       fprintf(stderr, "%s: size of islands must be > 0\n",
+               program_name);
+       exit(1);
+    }
 
     if (argc > 4)
        sp = atoi(argv[4]);
     else
        sp = DEFAULT_SPIKE;
-    sp = LIMIT_TO(sp, 0, 100);
+    if (sp < 0 || sp > 100) {
+       fprintf(stderr,
+               "%s: spike percentage must be between 0 and 100\n",
+               program_name);
+       exit(1);
+    }
 
     if (argc > 5)
        pm = atoi(argv[5]);
     else
        pm = DEFAULT_MOUNTAIN;
-    if (pm < 0)
-       pm = 0;
+    if (pm < 0 || pm > 100) {
+       fprintf(stderr,
+               "%s: mountain percentage must be between 0 and 100\n",
+               program_name);
+       exit(1);
+    }
 
     if (argc > 6)
        di = atoi(argv[6]);