Package 'wand'

Title: Retrieve Magic Attributes from Files and Directories
Description: MIME types are shorthand descriptors for file contents and can be determined from "magic" bytes in file headers, file contents or intuited from file extensions. Tools are provided to perform curated "magic" tests as well as mapping MIME types from a database of over 1,800 extension mappings.
Authors: Bob Rudis [aut, cre]
Maintainer: Bob Rudis <[email protected]>
License: MIT + file LICENSE
Version: 0.6.0
Built: 2024-09-20 08:05:10 UTC
Source: https://gitlab.com/hrbrmstr/wand

Help Index

Discover MIME type of a file based on contents

Description

There are a limited number of header "magic" bytes checked directly by this function but cover quite a bit of ground. After that, guess_content_type() is called which uses file extension-to-MIME mappings.

Usage

get_content_type(path, guess = TRUE, ...)

Arguments

path

path to a file
guess

if TRUE (the default), calls guess_content_type() if no internal rules match the magic header
...

passed on to guess_content_type() if guess is TRUE

Details

File an issue or PR if more magic-byte-level comparisons are required/desired. If no match is found, ??? is returned (see guess_content_type() for how to override this behaviour).

Value

character vector

Examples

get_content_type(system.file("extdat", "pass-through", "test.pdf", package="wand"))

Guess MIME type from filename (extension)

Description

Uses an internal database of over 1,800 file extension-to-MIME mappings to return one or more associated types for a given input path. If no match is found, ??? is returned.

Usage

guess_content_type(path, not_found = "???", custom_db = NULL)

Arguments

path

path to file
not_found

MIME type to use when the content cannot be guessed by file type.
custom_db

a single data frames each with two columns: mime_type and extension. These sources will be used along with the built-in sources and will take priority over the built-in sources. Note that the extensions should be lower case as they are in the official MIME database.

Value

character vector

Examples

guess_content_type(system.file("extdat", "pass-through", "test.pdf", package="wand"))

File extension-to-MIME mapping data frame

Description

built from the files found in the References

Note

Last updated 2019-07-27.

References

- <https://tools.ietf.org/html/rfc6838> - <https://www.iana.org/assignments/media-types/media-types.xhtml> - <https://s-randomfiles.s3.amazonaws.com/mime/allMimeTypes.json> - <https://cdn.jsdelivr.net/gh/jshttp/mime-db@master/db.json>

Retrieve 'Magic' Attributes from Files and Directories

Description

The 'libmagic' library provides functions to determine 'MIME' type and other metadata from files through their "magic" attributes. This is useful when you do not wish to rely solely on the honesty of a user or the extension on a file name. It also incorporates other metadata from the mime-db database https://github.com/jshttp/mime-db

Some important details

The header checking is minimal (i.e. nowhere near as comprehensive as libmagic) but covers quite a bit of ground. If there are content-check types from magic sources that you would like coded into the package, please file an issue and include the full line(s) from that linked magic.tab that you would like mapped.

Author(s)

Bob Rudis ([email protected])