newt: improve input filtering

diff --git a/rc/bin/newt b/rc/bin/newt
index 32e0b51b729a50da88adce0ce87e1193f8f2ee3a..7d6e8ab8e6017d640a6b9f1134e09bb3e0e79044 100755 (executable)
--- a/rc/bin/newt
+++ b/rc/bin/newt
@@ -154,8 +154,10 @@ while(){
        cmd=`{read}
        switch($cmd){
        case [0-9]*
-               post=$cmd(1)
-               printp $post
+               if(grep -s -e '^[0-9]+$' <{echo $cmd(1)}){
+                       post=$cmd(1)
+                       printp $post
+               }
        case b
                if(! ~ $post $posts(1)){
                        post=`{echo $post^-1 | bc}