удалить определения псевдонимов (remove alias definitions)
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)
unalias — remove alias definitions
Синопсис (Synopsis)
unalias alias-name...
unalias -a
Описание (Description)
The unalias utility shall remove the definition for each alias
name specified. See Section 2.3.1, Alias Substitution. The
aliases shall be removed from the current shell execution
environment; see Section 2.12, Shell Execution Environment.
Параметры (Options)
The unalias utility shall conform to the Base Definitions volume
of POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.
The following option shall be supported:
-a Remove all alias definitions from the current shell
execution environment.
Операнды (Operands)
The following operand shall be supported:
alias-name
The name of an alias to be removed.
Стандартный ввод (Stdin)
Not used.
Входные файлы (Input files)
None.
Переменные окружения (Environment variables)
The following environment variables shall affect the execution of
unalias:
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 Successful completion.
>0 One of the alias-name operands specified did not represent
a valid alias definition, or an error occurred.
Последствия ошибок (Consequences of errors)
Default.
The following sections are informative.
Использование в приложениях (Application usage)
Since unalias affects the current shell execution environment, it
is generally provided as a shell regular built-in.
Примеры (Examples)
None.
Обоснование (Rationale)
The unalias description is based on that from historical
KornShell implementations. Known differences exist between that
and the C shell. The KornShell version was adopted to be
consistent with all the other KornShell features in this volume
of POSIX.1‐2017, such as command line editing.
The -a option is the equivalent of the unalias * form of the C
shell and is provided to address security concerns about unknown
aliases entering the environment of a user (or application)
through the allowable implementation-defined predefined alias
route or as a result of an ENV file. (Although unalias could be
used to simplify the ``secure'' shell script shown in the command
rationale, it does not obviate the need to quote all command
names. An initial call to unalias -a would have to be quoted in
case there was an alias for unalias.)
Будущие направления (Future directions)
None.
Смотри также (See also)
Chapter 2, Shell Command Language, alias(1p)
The Base Definitions volume of POSIX.1‐2017, Chapter 8,
Environment Variables, Section 12.2, Utility Syntax Guidelines
