magicnum

README

magicnum

provides functions for checking magic numbers; currently supports a limited number of file formats

About

The functions within this package currently accepts and io.ReaderAt and trys to determine its format by comparing the data to the magic numbers of various formats.

It was created to determine the compression or archive format. Support for other magic numbers will be added as needed. This may also mean support for other formats, e.g. images.

Usage

Get:

go get github.com/mohae/magicnum

Import:

import github.com/mohae/magicnum

Get a reader. To check to see if any format is matched:

format, err := magicnum.GetFormat(r)

If magicnum isn't able to determine the format the format will be: Unsupported and an NotSupportedErr will be returned. Otherwise a magicnum.Format will be returned.

To check to see if it is of a specific format:

ok, err := magicnum.IsLZ4(r)

If the reader has data in the specified format, lz4 in this case, ok == true, otherwise ok == false. If an error occurs during processing, that will be returned.

Format

The magicnum.Format fulfills the Stringer interface so the common abbreviation for the format can be obtained with format.String().

Since formats can have different valid extensions, an extension can be matched to a Format by using magicnum.GetFormatFromString(ext).

Endianness

This library currently supports checking the magic number using little endian only. If there is need for big endian support, please file an issue or make a pull request. Ofc, the latter is preferred!

Copyright

Copyright 2015 by Joel Scoble. This is provided under the MIT License. Please check the included LICENSE file for more details.