| # isBinaryFile | |
| Detects if a file is binary in Node.js using ✨promises✨. Similar to [Perl's `-B` switch](http://stackoverflow.com/questions/899206/how-does-perl-know-a-file-is-binary), in that: | |
| - it reads the first few thousand bytes of a file | |
| - checks for a `null` byte; if it's found, it's binary | |
| - flags non-ASCII characters. After a certain number of "weird" characters, the file is flagged as binary | |
| Much of the logic is pretty much ported from [ag](https://github.com/ggreer/the_silver_searcher). | |
| Note: if the file doesn't exist or is a directory, an error is thrown. | |
| ## Installation | |
| ``` | |
| npm install isbinaryfile | |
| ``` | |
| ## Usage | |
| Returns `Promise<boolean>` (or just `boolean` for `*Sync`). `true` if the file is binary, `false` otherwise. | |
| ### isBinaryFile(filepath) | |
| * `filepath` - a `string` indicating the path to the file. | |
| ### isBinaryFile(bytes[, size]) | |
| * `bytes` - a `Buffer` of the file's contents. | |
| * `size` - an optional `number` indicating the file size. | |
| ### isBinaryFileSync(filepath) | |
| * `filepath` - a `string` indicating the path to the file. | |
| ### isBinaryFileSync(bytes[, size]) | |
| * `bytes` - a `Buffer` of the file's contents. | |
| * `size` - an optional `number` indicating the file size. | |
| ### Examples | |
| Here's an arbitrary usage: | |
| ```javascript | |
| const isBinaryFile = require("isbinaryfile").isBinaryFile; | |
| const fs = require("fs"); | |
| const filename = "fixtures/pdf.pdf"; | |
| const data = fs.readFileSync(filename); | |
| const stat = fs.lstatSync(filename); | |
| isBinaryFile(data, stat.size).then((result) => { | |
| if (result) { | |
| console.log("It is binary!") | |
| } | |
| else { | |
| console.log("No it is not.") | |
| } | |
| }); | |
| const isBinaryFileSync = require("isbinaryfile").isBinaryFileSync; | |
| const bytes = fs.readFileSync(filename); | |
| const size = fs.lstatSync(filename).size; | |
| console.log(isBinaryFileSync(bytes, size)); // true or false | |
| ``` | |
| ## Testing | |
| Run `npm install`, then run `npm test`. | |