OC-misc/mtar

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.