mkdtemp(3)

okay bestie, welcome to the mkdtemp(3) page from the Library Functions Manual — it's literally about making a unique temporary directory, and yes, it's iconic. 💖

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✨ NAME ✨

• mkdtemp — create a unique temporary directory 🎀

📚 LIBRARY 📚

Standard C library (libc, -lc) — that's where she lives, no cap. 💅

🌸 SYNOPSIS 🌸

#include <stdlib.h>

char *mkdtemp(char *template);

🧚 Feature Test Macro Requirements for glibc (see feature_test_macros(7)) 🧚

for mkdtemp(), the feature test macros are giving:

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 — like literally those six X's — and those get replaced with a string that makes the directory name unique. Then the directory is created with permissions 0700. And because it's gonna be modified, template must not be a string constant, bestie; it should be declared as a character array. 🫶

🎀 RETURN VALUE 🎀

On success, mkdtemp() returns a pointer to the modified template string. On failure, it returns NULL, and when that happens errno is set to indicate the error. success is slay, failure is 😭.

💀 ERRORS 💀

• EINVAL — the last six characters of template were not XXXXXX. Now template is unchanged. 💀

Also see mkdir(2) for other possible values for errno.

👑 ATTRIBUTES 👑

For an explanation of the terms used in this section, see attributes(7).

• Interface: mkdtemp()
• Attribute: Thread safety
• Value: MT-Safe

⭐ STANDARDS ⭐

POSIX.1-2008. periodt. 💅

🦋 HISTORY 🦋

glibc 2.1.91. NetBSD 1.4. POSIX.1-2008. the heritage, the range. 🦋

🌈 SEE ALSO 🌈

• mktemp(1)
• mkdir(2)
• mkstemp(3)
• mktemp(3)
• tempnam(3)
• tmpfile(3)
• tmpnam(3)

xoxo, Linux man-pages 6.20 — dated 2026-02-08 — page mkdtemp(3) 💖✨