PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT 

UNALIAS(1P)               POSIX Programmer's Manual              UNALIAS(1P)

PROLOG         top

       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         top

       unalias — remove alias definitions

SYNOPSIS         top

       unalias alias-name...
       unalias −a

DESCRIPTION         top

       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.

OPTIONS         top

       The unalias utility shall conform to the Base Definitions volume of
       POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.
       The following option shall be supported:
       −a        Remove all alias definitions from the current shell
                 execution environment.

OPERANDS         top

       The following operand shall be supported:
       alias-name
                 The name of an alias to be removed.

STDIN         top

       Not used.

INPUT FILES         top

       None.

ENVIRONMENT VARIABLES         top

       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.1‐2008, 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         top

       Default.

STDOUT         top

       Not used.

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       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.

CONSEQUENCES OF ERRORS         top

       Default.
       The following sections are informative.

APPLICATION USAGE         top

       Since unalias affects the current shell execution environment, it is
       generally provided as a shell regular built-in.

EXAMPLES         top

       None.

RATIONALE         top

       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.1‐2008, 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.)

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       Chapter 2, Shell Command Language, alias(1p)
       The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/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 .
IEEE/The Open Group                 2013                         UNALIAS(1P)