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

# mkfifo(1p)

make FIFO special files

## PROLOG

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

## NAME

mkfifo — make FIFO special files

## SYNOPSIS

```
mkfifo [-m mode] file...
```

## DESCRIPTION

The *mkfifo* utility shall create the FIFO special files specified by the operands, in the order specified.

For each *file* operand, the *mkfifo* utility shall perform actions equivalent to the *mkfifo*() function defined in the System Interfaces volume of POSIX.1‐2017, called with the following arguments:

- 1\.

  The *file* operand is used as the *path* argument.

- 2\.

  The value of the bitwise-inclusive OR of S\_IRUSR, S\_IWUSR, S\_IRGRP, S\_IWGRP, S\_IROTH, and S\_IWOTH is used as the *mode* argument. (If the **-m** option is specified, the value of the *mkfifo*() *mode* argument is unspecified, but the FIFO shall at no time have permissions less restrictive than the **-m** *mode* option-argument.)

## OPTIONS

The *mkfifo* utility shall conform to the Base Definitions volume of POSIX.1‐2017, *Section 12.2*, *Utility Syntax Guidelines*.

The following option shall be supported:

- **-m** *mode*

  Set the file permission bits of the newly-created FIFO to the specified *mode* value. The *mode* option-argument shall be the same as the *mode* operand defined for the *chmod* utility. In the *symbolic\_mode* strings, the *op* characters **'+'** and **'-'** shall be interpreted relative to an assumed initial mode of *a*= *rw*.

## OPERANDS

The following operand shall be supported:

- *file*

  A pathname of the FIFO special file to be created.

## STDIN

Not used.

## INPUT FILES

None.

## ENVIRONMENT VARIABLES

The following environment variables shall affect the execution of *mkfifo*:

- *LANG*

  Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume of POSIX.1‐2017, *Section 8.2*, *Internationalization Variables* for the precedence of internationalization variables used to determine the values of locale categories.)

- *LC\_ALL*

  If set to a non-empty string value, override the values of all the other internationalization variables.

- *LC\_CTYPE*

  Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments).

- *LC\_MESSAGES*

  Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error.

- *NLSPATH*

  Determine the location of message catalogs for the processing of *LC\_MESSAGES*.

## ASYNCHRONOUS EVENTS

Default.

## STDOUT

Not used.

## STDERR

The standard error shall be used only for diagnostic messages.

## OUTPUT FILES

None.

## EXTENDED DESCRIPTION

None.

## EXIT STATUS

The following exit values shall be returned:

- 0

  All the specified FIFO special files were created successfully.

- \>0

  An error occurred.

## CONSEQUENCES OF ERRORS

Default.

*The following sections are informative.*

## APPLICATION USAGE

None.

## EXAMPLES

None.

## RATIONALE

This utility was added to permit shell applications to create FIFO special files.

The **-m** option was added to control the file mode, for consistency with the similar functionality provided by the *mkdir* utility.

Early proposals included a **-p** option similar to the *mkdir* **-p** option that created intermediate directories leading up to the FIFO specified by the final component. This was removed because it is not commonly needed and is not common practice with similar utilities.

The functionality of *mkfifo* is described substantially through a reference to the *mkfifo*() function in the System Interfaces volume of POSIX.1‐2017. For example, by default, the mode of the FIFO file is affected by the file mode creation mask in accordance with the specified behavior of the *mkfifo*() function. In this way, there is less duplication of effort required for describing details of the file creation.

## FUTURE DIRECTIONS

None.

## SEE ALSO

*chmod*, *umask*

The Base Definitions volume of POSIX.1‐2017, *Chapter 8*, *Environment Variables*, *Section 12.2*, *Utility Syntax Guidelines*

The System Interfaces volume of POSIX.1‐2017, *mkfifo()*

## COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting\_bugs.html .