| # isBinaryFile |
| |
| Detects if a file is binary in Node.js. 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, is a directory, or is empty, the function returns `false`. |
| |
| ## Installation |
| |
| ``` |
| npm install isbinaryfile |
| ``` |
| |
| ## Usage |
| |
| ### isBinaryFile(filepath, callback) |
| |
| * `filepath`, a `string` indicating the path to the file. |
| * `callback`, a `function` for the callback. It has two arguments: |
| - `err`, the typical Node.js error argument |
| - `result`, a `boolean` of `true` or `false`, depending on if the file is binary |
| |
| |
| ### isBinaryFile(bytes, size, callback) |
| |
| * `bytes`, a `Buffer` of the file's contents. |
| * `size`, an optional `number` indicating the file size. |
| * `callback`, a `function` for the callback. It has two arguments: |
| - `err`, the typical Node.js error argument |
| - `result`, a `boolean` of `true` or `false`, depending on if the file is binary |
| |
| |
| ### isBinaryFile.sync(filepath) |
| |
| * `filepath`, a `string` indicating the path to the file. |
| |
| |
| ### isBinaryFile.sync(bytes, size) |
| |
| * `bytes`, a `Buffer` of the file's contents. |
| * `size`, an `number` indicating the file size. |
| |
| |
| Returns a `boolean` of `true` or `false`, depending on if the file is binary. |
| |
| ### Examples |
| |
| ```javascript |
| var isBinaryFile = require("isbinaryfile"); |
| |
| fs.readFile("some_file", function(err, data) { |
| fs.lstat("some_file", function(err, stat) { |
| isBinaryFile(data, stat.size, function (err, result) { |
| if (!err) { |
| if (result) { |
| console.log("It is!") |
| } |
| else { |
| console.log("No.") |
| } |
| } |
| }); |
| }); |
| }); |
| |
| isBinaryFile.sync("some_file"); // true or false |
| var bytes = fs.readFileSync(("some_file")); |
| var size = fs.lstatSync(("some_file").size; |
| isBinaryFile.sync(bytes, size); // true or false |
| ``` |
| |
| ## Testing |
| |
| Run `npm install` to install `mocha`, then run `npm test`. |