README.md

node-temp
=========

Temporary files, directories, and streams for Node.js.

Handles generating a unique file/directory name under the appropriate
system temporary directory, changing the file to an appropriate mode,
and supports automatic removal (if asked)

`temp` has a similar API to the `fs` module.

Node.js Compatibility
---------------------

Supports v0.10.0+.

[![Build Status](https://travis-ci.org/bruce/node-temp.png)](https://travis-ci.org/bruce/node-temp)

Please let me know if you have problems running it on a later version of Node.js or
have platform-specific problems.

Installation
------------

Install it using [npm](http://github.com/isaacs/npm):

    $ npm install temp

Or get it directly from:
http://github.com/bruce/node-temp

Synopsis
--------

You can create temporary files with `open` and `openSync`, temporary
directories with `mkdir` and `mkdirSync`, or you can get a unique name
in the system temporary directory with `path`.

Working copies of the following examples can be found under the
`examples` directory.

### Temporary Files

To create a temporary file use `open` or `openSync`, passing
them an optional prefix, suffix, or both (see below for details on
affixes). The object passed to the callback (or returned) has
`path` and `fd` keys:

```javascript
{ path: "/path/to/file",
, fd: theFileDescriptor
}
```

In this example we write to a temporary file and call out to `grep` and
`wc -l` to determine the number of time `foo` occurs in the text.  The
temporary file is chmod'd `0600` and cleaned up automatically when the
process at exit (because `temp.track()` is called):

```javascript
var temp = require('temp'),
    fs   = require('fs'),
    util  = require('util'),
    exec = require('child_process').exec;

// Automatically track and cleanup files at exit
temp.track();

// Fake data
var myData = "foo\nbar\nfoo\nbaz";

// Process the data (note: error handling omitted)
temp.open('myprefix', function(err, info) {
  if (!err) {
    fs.write(info.fd, myData);
    fs.close(info.fd, function(err) {
      exec("grep foo '" + info.path + "' | wc -l", function(err, stdout) {
        util.puts(stdout.trim());
      });
    });
  }
});
```

### Want Cleanup? Make sure you ask for it.

As noted in the example above, if you want temp to track the files and
directories it creates and handle removing those files and directories
on exit, you must call `track()`. The `track()` function is chainable,
and it's recommended that you call it when requiring the module.

```javascript
var temp = require("temp").track();
```

Why is this necessary? In pre-0.6 versions of temp, tracking was
automatic. While this works great for scripts and
[Grunt tasks](http://gruntjs.com/), it's not so great for long-running
server processes. Since that's arguably what Node.js is _for_, you
have to opt-in to tracking.

But it's easy.

#### Cleanup anytime

When tracking, you can run `cleanup()` and `cleanupSync()` anytime
(`cleanupSync()` will be run for you on process exit). An object will
be returned (or passed to the callback) with cleanup counts and
the file/directory tracking lists will be reset.

```javascript
> temp.cleanupSync();
{ files: 1,
  dirs:  0 }
```

```javascript
> temp.cleanup(function(err, stats) {
    console.log(stats);
  });
{ files: 1,
  dirs:  0 }
```

Note: If you're not tracking, an error ("not tracking") will be passed
to the callback.

### Temporary Directories

To create a temporary directory, use `mkdir` or `mkdirSync`, passing
it an optional prefix, suffix, or both (see below for details on affixes).

In this example we create a temporary directory, write to a file
within it, call out to an external program to create a PDF, and read
the result.  While the external process creates a lot of additional
files, the temporary directory is removed automatically at exit (because
`temp.track()` is called):

```javascript
var temp = require('temp'),
    fs   = require('fs'),
    util = require('util'),
    path = require('path'),
    exec = require('child_process').exec;

// Automatically track and cleanup files at exit
temp.track();

// For use with ConTeXt, http://wiki.contextgarden.net
var myData = "\\starttext\nHello World\n\\stoptext";

temp.mkdir('pdfcreator', function(err, dirPath) {
  var inputPath = path.join(dirPath, 'input.tex')
  fs.writeFile(inputPath, myData, function(err) {
    if (err) throw err;
    process.chdir(dirPath);
    exec("texexec '" + inputPath + "'", function(err) {
      if (err) throw err;
      fs.readFile(path.join(dirPath, 'input.pdf'), function(err, data) {
        if (err) throw err;
        sys.print(data);
      });
    });
  });
});
```

### Temporary Streams

To create a temporary WriteStream, use 'createWriteStream', which sits
on top of `fs.createWriteStream`. The return value is a
`fs.WriteStream` whose `path` is registered for removal when
`temp.cleanup` is called (because `temp.track()` is called).

```javascript
var temp = require('temp');

// Automatically track and cleanup files at exit
temp.track();

var stream = temp.createWriteStream();
stream.write("Some data");
// Maybe do some other things
stream.end();
```

### Affixes

You can provide custom prefixes and suffixes when creating temporary
files and directories. If you provide a string, it is used as the prefix
for the temporary name. If you provide an object with `prefix`,
`suffix` and `dir` keys, they are used for the temporary name.

Here are some examples:

* `"aprefix"`: A simple prefix, prepended to the filename; this is
  shorthand for:
* `{prefix: "aprefix"}`: A simple prefix, prepended to the filename
* `{suffix: ".asuffix"}`: A suffix, appended to the filename
  (especially useful when the file needs to be named with specific
  extension for use with an external program).
* `{prefix: "myprefix", suffix: "mysuffix"}`: Customize both affixes
* `{dir: path.join(os.tmpDir(), "myapp")}`: default prefix and suffix
  within a new temporary directory.
* `null`: Use the defaults for files and directories (prefixes `"f-"`
  and `"d-"`, respectively, no suffixes).

In this simple example we read a `pdf`, write it to a temporary file with
a `.pdf` extension, and close it.

```javascript
var fs   = require('fs'),
    temp = require('temp');

fs.readFile('/path/to/source.pdf', function(err, data) {
  temp.open({suffix: '.pdf'}, function(err, info) {
    if (err) throw err;
    fs.write(info.fd, contents);
    fs.close(info.fd, function(err) {
      if (err) throw err;
      // Do something with the file
    });
  });
});
```

### Just a path, please

If you just want a unique name in your temporary directory, use
`path`:

```javascript
var fs = require('fs');
var tempName = temp.path({suffix: '.pdf'});
// Do something with tempName
```

Note: The file isn't created for you, and the mode is not changed  -- and it
will not be removed automatically at exit.  If you use `path`, it's
all up to you.

Using it with Grunt
-------------------

If you want to use the module with [Grunt](http://gruntjs.com/), make sure you
use `async()` in your Gruntfile:

```javascript
module.exports = function (grunt) {
  var temp = require("temp");
  temp.track(); // Cleanup files, please
  grunt.registerTask("temptest", "Testing temp", function() {

    var done = this.async(); // Don't forget this!

    grunt.log.writeln("About to write a file...");
    temp.open('tempfile', function(err, info) {
      // File writing shenanigans here
      grunt.log.writeln("Wrote a file!")

      done(); // REALLY don't forget this!

    });
  });
};
```

For more information, see the [Grunt FAQ](http://gruntjs.com/frequently-asked-questions#why-doesn-t-my-asynchronous-task-complete).

Testing
-------

```sh
$ npm test
```

Contributing
------------

You can find the repository at:
http://github.com/bruce/node-temp

Issues/Feature Requests can be submitted at:
http://github.com/bruce/node-temp/issues

I'd really like to hear your feedback, and I'd love to receive your
pull-requests!

Copyright
---------

Copyright (c) 2010-2014 Bruce Williams. This software is licensed
under the MIT License, see LICENSE for details.