```
#!/bin/bash
# enc.txt.sh
file=enc.txt
encode=$(cat "$file")
enc_test=`echo $encode | cut -c1-10`
while [ "$enc_test" != "Bugs_Bunny" ]
do
encode=`echo $encode | base64 -d`
enc_test=`echo $encode | cut -c1-10`
done
echo $encode
```

```
# ./enc.txt.sh
Bugs_Bunny{N0T_H4Rd_4T_4ll}
```