---
name: "mkdtemp"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/mkdtemp"
---

# mkdtemp(3)

create a unique temporary directory

## NAME

mkdtemp - create a unique temporary directory

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <stdlib.h>
```

**char \*mkdtemp(char \****template***);**

Feature Test Macro Requirements for glibc (see [**feature\_test\_macros**(7)](/feature_test_macros/7.md)):

**mkdtemp**():

```
    /* Since glibc 2.19: */ _DEFAULT_SOURCE
        || /* glibc 2.19 and earlier: */ _BSD_SOURCE
        || /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L
```

## DESCRIPTION

The **mkdtemp**() function generates a uniquely named temporary directory from *template*. The last six characters of *template* must be XXXXXX and these are replaced with a string that makes the directory name unique. The directory is then created with permissions 0700. Since it will be modified, *template* must not be a string constant, but should be declared as a character array.

## RETURN VALUE

The **mkdtemp**() function returns a pointer to the modified template string on success, and NULL on failure, in which case *errno* is set to indicate the error.

## ERRORS

- **EINVAL**

  The last six characters of *template* were not XXXXXX. Now *template* is unchanged.

Also see [**mkdir**(2)](/mkdir/2.md) for other possible values for *errno*.

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **mkdtemp**() | Thread safety | MT-Safe |

## STANDARDS

POSIX.1-2008.

## HISTORY

glibc 2.1.91. NetBSD 1.4. POSIX.1-2008.

## SEE ALSO

[**mktemp**(1)](/mktemp/1.md), [**mkdir**(2)](/mkdir/2.md), [**mkstemp**(3)](/mkstemp/3.md), [**mktemp**(3)](/mktemp/3.md), [**tempnam**(3)](/tempnam/3.md), [**tmpfile**(3)](/tmpfile/3.md), [**tmpnam**(3)](/tmpnam/3.md)