C-sar

A simple Caesar cipher encrypter/decrypter for POSIX systems. Encrypts a string or file and prints cipher to stdout.

C-sar features:

• En/decryption of strings and files.
• Option for showing all 26 possible encryptions (-a).

Installation

Make it (using make) with make clean from the project root. This uses gcc, so that is also required.

Usage

c-sar [key] [string] [-i inputfile] [-a] [-h] [-v]

Example usage:

• c-sar -h will print some (hopefully) helpful text.
• c-sar 2 hello will encrypt the string "hello" with the key 2.
• c-sar -a hello will generate all possible encryptions of the string "hello"
• c-sar 42 "forty two" will encrypt the string "forty two" with the key 42.
• c-sar 5 -i plaintext.txt will encrypt the contents of file plaintext.txt with the key 5.

Known issues

• Currently only supports English letters (a-z) (other characters are simply copied to the cipher as they are). Support for custom alphabets is planned for the future.
• Currently only works on POSIX systems. This is due to how the program reads files. Windows support is planned for the future.