Explicitly specify -? as an option in tred2

diff --git a/cmd/tools/tred2.c b/cmd/tools/tred2.c
index 297c1d9dbc82476de1d67149fea0a6d600ee4b72..511e513246aef164881df21050e35ed919cec175 100644 (file)
--- a/cmd/tools/tred2.c
+++ b/cmd/tools/tred2.c
@@ -60,10 +60,10 @@ static void init(int argc, char *argv[])
 
     CmdName = argv[0];
     opterr = 0;
-    while ((c = getopt(argc, argv, ":")) != -1) {
+    while ((c = getopt(argc, argv, ":?")) != -1) {
        switch (c) {
        case '?':
-           if (optopt == '?')
+           if (optopt == '\0')
                usage(0);
            else {
                fprintf(stderr, "%s: option -%c unrecognized\n",