OC-misc/mtar/README.md

# mtar - Minitel Archiver

mtar is a file format for storing multiple files in a single file, much like tar, cpio or zip.

## File format

mtar archive files consist of a number of file entries, in any combination of the following formats:

### v1 format

- 0xFFFF (for differentiating versioned headers from legacy v0 headers)
- version byte, with the value 1
- 2 bytes file name length
- the file name
- 8 bytes file content length
- the file contents

### Legacy v0 format

- 2 bytes file name length
- the file name
- 2 bytes file content length
- the file contents

Archives are terminated either by the end of file, or a record with a name length of zero.

## libmtar

libmtar is the reference implementation of mtar. It provides two functions:

 - `libmtar.genHeader(string: name, number: len): string`  
Generates an mtar file header for a file called *name* that is *len* bytes long.
 - `libmtar.iter(table: stream): function`  
Given buffer *stream*, returns an iterator suitable for use with *for* that returns, for each iteration, the file name, a function to read from the file, and the length of the file.