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React-Redux site for The Reporter Foundation in Taiwan
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# 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`, an `number` indicating the size of the file.
* `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`, an `number` indicating the size of the file.
* `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");
if (isBinaryFile(process.argv[2]))
console.log("It is!")
else
console.log("No.")
fs.readFile(process.argv[2], function(err, data) {
fs.lstat(process.argv[2], function(err, stat) {
if (isBinaryFile(data, stat.size))
console.log("It is!")
else
console.log("No.")
});
});
isBinaryFile.sync(process.argv[2]); // true or false
var stat = fs.lstatSync(process.argv[2]);
isBinaryFile.sync(process.argv[2], stat.size); // true or false
```
## Testing
Run `npm install` to install `mocha`, then run `npm test`.