tmp

Temporary file and directory creator

Tmp

A simple temporary file and directory creator for node.js.

The main difference between bruce's node-temp is that mine more aggressively checks for the existence of the newly created temporary file and creates the new file with O_EXCL instead of simple O_CREAT | O_RDRW, so it is safer.

Tmp offers both an asynchronous and a synchronous API. For all API calls, all the parameters are optional.

Tmp uses crypto for determining random file names, or, when using templates, a six letter random identifier. And just in case that you do not have that much entropy left on your system, Tmp will fall back to pseudo random numbers.

You can set whether you want to remove the temporary file on process exit or not, and the destination directory can also be set.

npm install tmp

Simple temporary file creation, the file will be closed and unlinked on process exit.

var tmp = require('tmp');
 
tmp.file(function _tempFileCreated(errpathfdcleanupCallback) {
  if (err) throw err;
 
  console.log("File: ", path);
  console.log("Filedescriptor: ", fd);
  
  // If we don't need the file anymore we could manually call the cleanupCallback 
  // But that is not necessary if we didn't pass the keep option because the library 
  // will clean after itself. 
  cleanupCallback();
});

A synchronous version of the above.

var tmp = require('tmp');
 
var tmpobj = tmp.fileSync();
console.log("File: ", tmpobj.name);
console.log("Filedescriptor: ", tmpobj.fd);
  
// If we don't need the file anymore we could manually call the removeCallback 
// But that is not necessary if we didn't pass the keep option because the library 
// will clean after itself. 
tmpobj.removeCallback();

Note that this might throw an exception if either the maximum limit of retries for creating a temporary name fails, or, in case that you do not have the permission to write to the directory where the temporary file should be created in.

Simple temporary directory creation, it will be removed on process exit.

If the directory still contains items on process exit, then it won't be removed.

var tmp = require('tmp');
 
tmp.dir(function _tempDirCreated(errpathcleanupCallback) {
  if (err) throw err;
 
  console.log("Dir: ", path);
  
  // Manual cleanup 
  cleanupCallback();
});

If you want to cleanup the directory even when there are entries in it, then you can pass the unsafeCleanup option when creating it.

A synchronous version of the above.

var tmp = require('tmp');
 
var tmpobj = tmp.dirSync();
console.log("Dir: ", tmpobj.name);
// Manual cleanup 
tmpobj.removeCallback();

Note that this might throw an exception if either the maximum limit of retries for creating a temporary name fails, or, in case that you do not have the permission to write to the directory where the temporary directory should be created in.

It is possible with this library to generate a unique filename in the specified directory.

var tmp = require('tmp');
 
tmp.tmpName(function _tempNameGenerated(errpath) {
    if (err) throw err;
 
    console.log("Created temporary filename: ", path);
});

A synchrounous version of the above.

var tmp = require('tmp');
 
var name = tmp.tmpNameSync();
console.log("Created temporary filename: ", name);

Creates a file with mode 0644, prefix will be prefix- and postfix will be .txt.

var tmp = require('tmp');
 
tmp.file({ mode: 0644, prefix: 'prefix-', postfix: '.txt' }, function _tempFileCreated(errpathfd) {
  if (err) throw err;
 
  console.log("File: ", path);
  console.log("Filedescriptor: ", fd);
});

A synchronous version of the above.

var tmp = require('tmp');
 
var tmpobj = tmp.fileSync({ mode: 0644, prefix: 'prefix-', postfix: '.txt' });
console.log("File: ", tmpobj.name);
console.log("Filedescriptor: ", tmpobj.fd);

Creates a directory with mode 0755, prefix will be myTmpDir_.

var tmp = require('tmp');
 
tmp.dir({ mode: 0750, prefix: 'myTmpDir_' }, function _tempDirCreated(errpath) {
  if (err) throw err;
 
  console.log("Dir: ", path);
});

Again, a synchronous version of the above.

var tmp = require('tmp');
 
var tmpobj = tmp.dirSync({ mode: 0750, prefix: 'myTmpDir_' });
console.log("Dir: ", tmpobj.name);

Creates a new temporary directory with mode 0700 and filename like /tmp/tmp-nk2J1u.

var tmp = require('tmp');
 
tmp.dir({ template: '/tmp/tmp-XXXXXX' }, function _tempDirCreated(errpath) {
  if (err) throw err;
 
  console.log("Dir: ", path);
});

This will behave similarly to the asynchronous version.

var tmp = require('tmp');
 
var tmpobj = tmp.dirSync({ template: '/tmp/tmp-XXXXXX' });
console.log("Dir: ", tmpobj.name);

The tmpName() function accepts the prefix, postfix, dir, etc. parameters also:

var tmp = require('tmp');
 
tmp.tmpName({ template: '/tmp/tmp-XXXXXX' }, function _tempNameGenerated(errpath) {
    if (err) throw err;
 
    console.log("Created temporary filename: ", path);
});

The tmpNameSync() function works similarly to tmpName().

var tmp = require('tmp');
var tmpname = tmp.tmpNameSync({ template: '/tmp/tmp-XXXXXX' });
console.log("Created temporary filename: ", tmpname);

One may want to cleanup the temporary files even when an uncaught exception occurs. To enforce this, you can call the setGracefulCleanup() method:

var tmp = require('tmp');
 
tmp.setGracefulCleanup();

All options are optional :)

  • mode: the file mode to create with, it fallbacks to 0600 on file creation and 0700 on directory creation
  • prefix: the optional prefix, fallbacks to tmp- if not provided
  • postfix: the optional postfix, fallbacks to .tmp on file creation
  • template: mkstemps like filename template, no default
  • dir: the optional temporary directory, fallbacks to system default (guesses from environment)
  • tries: how many times should the function try to get a unique filename before giving up, default 3
  • keep: signals that the temporary file or directory should not be deleted on exit, default is false, means delete
    • Please keep in mind that it is recommended in this case to call the provided cleanupCallback function manually.
  • unsafeCleanup: recursively removes the created temporary directory, even when it's not empty. default is false