This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       Default.

       Default.

       Thefollowingsectionsareinformative.

       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 .

IEEE/The Open Group                                   2017                                         ALIAS(1POSIX)

       The  alias  utility  shall  create  or  redefine  alias definitions or write the values of existing alias
       definitions to standard output. An alias definition provides a string value that shall replace a  command
       name when it is encountered; see Section2.3.1, AliasSubstitution.

       An  alias  definition shall affect the current shell execution environment and the execution environments
       of the subshells of the current shell. When used as specified by this volume of POSIX.1‐2017,  the  alias
       definition  shall  not affect the parent process of the current shell nor any utility environment invoked
       by the shell; see Section2.12, ShellExecutionEnvironment.

       The following environment variables shall affect the execution of alias:

       LANG      Provide a default value for the internationalization variables that are unset or null. (See the
                 Base Definitions volume of POSIX.1‐2017, Section8.2, InternationalizationVariables  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.

        1. Create a short alias for a commonly used ls command:

               alias lf="ls -CF"

        2. Create a simple ``redo'' command to repeat previous entries in the command history file:

               alias r='fc -s'

        3. Use 1K units for du:

               alias du=du\ -k

        4. Set up nohup so that it can deal with an argument that is itself an alias name:

               alias nohup="nohup "

       The following exit values shall be returned:

        0    Successful completion.

       >0    One of the name operands specified did not have an alias definition, or an error occurred.

       None.

       None.

       None.

       alias — define or display aliases

       The following operands shall be supported:

       alias-name
                 Write the alias definition to standard output.

       alias-name=string
                 Assign the value of string to the alias alias-name.

       If no operands are given, all alias definitions shall be written to standard output.

       None.

       None.

       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.

       The alias description is based on 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.

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

       Historical  versions  of the KornShell have allowed aliases to be exported to scripts that are invoked by
       the same shell. This is triggered by the alias-x flag; it is allowed by this volume of POSIX.1‐2017 only
       when an explicit extension such as -x is used. The standard developers considered that  aliases  were  of
       use primarily to interactive users and that they should normally not affect shell scripts called by those
       users; functions are available to such scripts.

       Historical  versions  of the KornShell had not written aliases in a quoted manner suitable for reentry to
       the shell, but this volume of POSIX.1‐2017 has made this a requirement for all similar output. Therefore,
       consistency was chosen over this detail of historical practice.

Section2.9.5, FunctionDefinitionCommand

       The Base Definitions volume of POSIX.1‐2017, Chapter8, EnvironmentVariables

       The standard error shall be used only for diagnostic messages.

       Not used.

       The format for displaying aliases (when no operands or only name operands are specified) shall be:

           "%s=%s\n", name, value

       The  value  string  shall  be  written with appropriate quoting so that it is suitable for reinput to the
       shell. See the description of shell quoting in Section2.2, Quoting.

       alias [alias-name[=string]...]