Create a temporary file or directory

File

Use ioutil.TempFile in package io/ioutil to create a globally unique temporary file. It’s your own job to remove the file when it’s no longer needed.

file, err := ioutil.TempFile("dir", "prefix")
if err != nil {
	log.Fatal(err)
}
defer os.Remove(file.Name())

fmt.Println(file.Name()) // For example "dir/prefix054003078"

The call to ioutil.TempFile

• creates a new file with a name starting with "prefix" in the directory "dir",
• opens the file for reading and writing,
• and returns the new *os.File.

To put the new file in os.TempDir(), the default directory for temporary files, call ioutil.TempFile with an empty directory string.

Add a suffix to the temporary file nameGo 1.11

Starting with Go 1.11, if the second string given to TempFile includes a "*", the random string replaces this "*".

file, err := ioutil.TempFile("dir", "myname.*.bat")
if err != nil {
	log.Fatal(err)
}
defer os.Remove(file.Name())

fmt.Println(file.Name()) // For example "dir/myname.054003078.bat"

If no "*" is included the old behavior is retained, and the random digits are appended to the end.

Directory

Use ioutil.TempDir in package io/ioutil to create a globally unique temporary directory.

dir, err := ioutil.TempDir("dir", "prefix")
if err != nil {
	log.Fatal(err)
}
defer os.RemoveAll(dir)

The call to ioutil.TempDir

• creates a new directory with a name starting with "prefix" in the directory "dir"
• and returns the path of the new directory.

To put the new directory in os.TempDir(), the default directory for temporary files, call ioutil.TempDir with an empty directory string.

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