---
name: "tmpfile"
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/tmpfile"
---

# tmpfile(3)

create a temporary file

## NAME

tmpfile - create a temporary file

## LIBRARY

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

## SYNOPSIS

```
#include <stdio.h>
```

**FILE \*tmpfile(void);**

## DESCRIPTION

The **tmpfile**() function opens a unique temporary file in binary read/write (w+b) mode. The file will be automatically deleted when it is closed or the program terminates.

## RETURN VALUE

The **tmpfile**() function returns a stream descriptor, or NULL if a unique filename cannot be generated or the unique file cannot be opened. In the latter case, *errno* is set to indicate the error.

## ERRORS

- **EACCES**

  Search permission denied for directory in file's path prefix.

- **EEXIST**

  Unable to generate a unique filename.

- **EINTR**

  The call was interrupted by a signal; see [**signal**(7)](/signal/7.md).

- **EMFILE**

  The per-process limit on the number of open file descriptors has been reached.

- **ENFILE**

  The system-wide limit on the total number of open files has been reached.

- **ENOSPC**

  There was no room in the directory to add the new filename.

- **EROFS**

  Read-only filesystem.

## ATTRIBUTES

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

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

## VERSIONS

The standard does not specify the directory that **tmpfile**() will use. glibc will try the path prefix *P\_tmpdir* defined in *\<stdio.h\>*, and if that fails, then the directory */tmp*.

## STANDARDS

C11, POSIX.1-2008.

## HISTORY

POSIX.1-2001, C89, SVr4, 4.3BSD, SUSv2.

## NOTES

POSIX.1-2001 specifies: an error message may be written to *stdout* if the stream cannot be opened.

## SEE ALSO

[**exit**(3)](/exit/3.md), [**mkstemp**(3)](/mkstemp/3.md), [**mktemp**(3)](/mktemp/3.md), [**tempnam**(3)](/tempnam/3.md), [**tmpnam**(3)](/tmpnam/3.md)