| # mime_guess  [](https://crates.io/crates/mime_guess) | |
| MIME/MediaType guessing by file extension. | |
| Uses a static map of known file extension -> MIME type mappings. | |
| **Returning Contributors: New Requirements for Submissions Below** | |
| ##### Required Rust Version: 1.33 | |
| #### [Documentation](https://docs.rs/mime_guess/) | |
| ### Versioning | |
| Due to a mistaken premature release, `mime_guess` currently publicly depends on a pre-1.0 `mime`, | |
| which means `mime` upgrades are breaking changes and necessitate a major version bump. | |
| Refer to the following table to find a version of `mime_guess` which matches your version of `mime`: | |
| | `mime` version | `mime_guess` version | | |
| |----------------|----------------------| | |
| | `0.1.x, 0.2.x` | `1.x.y` | | |
| | `0.3.x` | `2.x.y` | | |
| #### Note: MIME Types Returned Are Not Stable/Guaranteed | |
| The media types returned for a given extension are not considered to be part of the crate's | |
| stable API and are often updated in patch (`x.y.z + 1`) releases to be as correct as possible. MIME | |
| changes are backported to previous major releases on a best-effort basis. | |
| Note that only the extensions of paths/filenames are inspected in order to guess the MIME type. The | |
| file that may or may not reside at that path may or may not be a valid file of the returned MIME type. | |
| Be wary of unsafe or un-validated assumptions about file structure or length. | |
| An extension may also have multiple applicable MIME types. When more than one is returned, the first | |
| is considered to be the most "correct"--see below for elaboration. | |
| Contributing | |
| ----------- | |
| #### Adding or correcting MIME types for extensions | |
| Is the MIME type for a file extension wrong or missing? Great! | |
| Well, not great for us, but great for you if you'd like to open a pull request! | |
| The file extension -> MIME type mappings are listed in `src/mime_types.rs`. | |
| **The list is sorted lexicographically by file extension, and all extensions are lowercase (where applicable).** | |
| The former is necessary to support fallback to binary search when the | |
| `phf-map` feature is turned off, and for the maintainers' sanity. | |
| The latter is only for consistency's sake; the search is case-insensitive. | |
| Simply add or update the appropriate string pair(s) to make the correction(s) needed. | |
| Run `cargo test` to make sure the library continues to work correctly. | |
| #### Important! Citing the corrected MIME type | |
| When opening a pull request, please include a link to an official document or RFC noting | |
| the correct MIME type for the file type in question **in the commit message** so | |
| that the commit history can be used as an audit trail. | |
| Though we're only guessing here, we like to be as correct as we can. | |
| It makes it much easier to vet your contribution if we don't have to search for corroborating material. | |
| #### Multiple MIME types per extension | |
| As of `2.0.0`, multiple MIME types per extension are supported. The first MIME type in the list for | |
| a given extension should be the most "correct" so users who only care about getting a single MIME | |
| type can use the `first*()` methods. | |
| The definition of "correct" is open to debate, however. In the author's opinion this should be | |
| whatever is defined by the latest IETF RFC for the given file format, or otherwise explicitly | |
| supercedes all others. | |
| If an official IANA registration replaces an older "experimental" style media type, please | |
| place the new type before the old type in the list, but keep the old type for reference: | |
| ``` | |
| - ("md", &["text/x-markdown"]), | |
| + ("md", &["text/markdown", "text/x-markdown"]), | |
| ``` | |
| #### Changes to the API or operation of the crate | |
| We're open to changes to the crate's API or its inner workings, breaking or not, if it improves the overall operation, efficiency, or ergonomics of the crate. However, it would be a good idea to open an issue on the repository so we can discuss your proposed changes and decide how best to approach them. | |
| License | |
| ------- | |
| MIT (See the `LICENSE` file in this repository for more information.) |