создавать специальные файлы FIFO (make FIFO special files)
Пролог (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.
Имя (Name)
mkfifo — make FIFO special files
Синопсис (Synopsis)
mkfifo [-m mode] file...
Описание (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.)
Параметры (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.
Операнды (Operands)
The following operand shall be supported:
file A pathname of the FIFO special file to be created.
Стандартный ввод (Stdin)
Not used.
Входные файлы (Input files)
None.
Переменные окружения (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.
Асинхронные события (Asynchronous events)
Default.
Стандартный вывод (Stdout)
Not used.
Стандартный вывод сообщений (Stderr)
The standard error shall be used only for diagnostic messages.
Выходные файлы (Output files)
None.
Расширенное описание (Extended description)
None.
Статус выхода (Exit)
The following exit values shall be returned:
0 All the specified FIFO special files were created
successfully.
>0 An error occurred.
Последствия ошибок (Consequences of errors)
Default.
The following sections are informative.
Использование в приложениях (Application usage)
None.
Примеры (Examples)
None.
Обоснование (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.
Будущие направления (Future directions)
None.
Смотри также (See also)
chmod(1p), umask(1p)
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(3p)
