# Grace Hopper
## Description> Grace Brewster Hopper (née Murray; December 9, 1906 – January 1, 1992) was an American computer scientist, mathematician, and United States Navy rear admiral. One of the first programmers of the Harvard Mark I computer, she was a pioneer of computer programming who invented one of the first linkers. Hopper was the first to devise the theory of machine-independent programming languages, and the FLOW-MATIC programming language she created using this theory was later extended to create COBOL, an early high-level programming language still in use today. - Wikipedia Entry
> Chal: Command this webapp like this Navy Real Admiral
## Challenge URL[Challenge Link](https://cyberheroines-web-srv2.chals.io/vulnerable.php)
## Solution* The challenge says to enter a command but `ls` does not work. ```Output:You think it's that easy? Try harder!```* Use `dir -a` to list directory contents even hidden files![dir](https://i.imgur.com/lCgZ68j.png)* `ls`, `cat`, `more`, `less`, `head`, `tail` commands are blacklisted.* So to view file contents, we can use `strings` or just `grep` for the flag format to view file contents* Running `strings` on `cyberheroines.sh` gives us the flag```FLAG="CHCTF{t#!$_!s_T#3_w@Y}"echo -n "$FLAG" | sha256sum > cyberheroines.txt```
### FLAG```CHCTF{t#!$_!s_T#3_w@Y}```