caesar

A simple C program that encodes files using Caesar's cipher.

Building

Just run make.

Usage

# Reading from stdin
$ echo "aaabbbccc" | ./caesar
nnnoooppp

# Specifying how many letters to shift by
$ echo "abc" | ./caesar --shift 1
bcd

# Using input and output files
$ echo "some words" > a.txt
$ ./caesar --input a.txt --output b.txt
$ cat b.txt
fbzr jbeqf

# The program ignores non-ascii letters
$ echo "ABC +-/ abc" | ./caesar
NOP +-/ nop

# To reverse an operation use negative shift
$ echo "some phrase" | ./caesar -s 10 | ./caesar -s -10
some phrase