MiniCompress

A small file compressor and decompressor using run length encoding (RLE), implemented in C, with a Python command line wrapper.

RLE replaces runs of repeated bytes with a (count, byte) pair. It works well on files with long runs of repeated values, such as simple bitmaps, some logs, or padded binary formats. On typical text or already compressed files, it usually makes the file larger, since most bytes do not repeat. This tool reports the result either way so you know what happened.

Build

make

This compiles rle.c into an rle binary in the same folder.

Usage

Compress one or more files (creates <file>.rle alongside the original):

python3 compress.py compress notes.txt
python3 compress.py compress file1.bin file2.bin

Decompress an .rle file (creates <name>.out):

python3 compress.py decompress notes.txt.rle

How it works

• rle.c reads the input byte by byte. For each run of identical bytes (up to 255 in a row), it writes one byte for the count and one byte for the value. Decompression reverses this by reading each (count, byte) pair and writing the byte that many times.
• compress.py calls the rle binary for the actual work, then reports the original size, compressed size, and whether the file actually got smaller.

Notes

• The original file is never modified or deleted, compress and decompress always write a new file.
• Compression and decompression are lossless, the original bytes are reproduced exactly.