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 v6.0.0+.

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:

$ 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:

{ 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):

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, (err) => {
        console.log(err);
    });
    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.

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, 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.

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

> 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):

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 with a path property containing the temporary file path for the stream. The path is registered for removal when temp.cleanup is called (because temp.track() is called).

var temp = require('temp');
 
// Automatically track and cleanup files at exit
temp.track();
 
var stream = temp.createWriteStream();
// stream.path contains the temporary file path for the stream
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.

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, data, (err) => {
            console.log(err)
        });
    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:

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.

Testing

$ 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.