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NAME
       alias - define or display aliases


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


DESCRIPTION
       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 Alias Substitution .

       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 IEEE Std 1003.1-2001, the
       alias  definition  shall  not  affect the parent process of the current shell nor any utility environment
       invoked by the shell; see Shell Execution Environment .


OPTIONS
       None.


OPERANDS
       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.


STDIN
       Not used.


INPUT FILES
       None.


ENVIRONMENT VARIABLES
       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 IEEE Std 1003.1-2001, 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
       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 Quoting .


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     Successful completion.

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


CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.


APPLICATION USAGE
       None.


EXAMPLES
        1. Change ls to give a columnated, more annotated output:

           alias ls="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 "


RATIONALE
       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 IEEE Std 1003.1-2001, 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
       IEEE Std 1003.1-2001 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 IEEE Std 1003.1-2001 has made this a requirement for all similar output.
       Therefore, consistency with this volume of IEEE Std 1003.1-2001 was chosen over this detail of historical
       practice.


FUTURE DIRECTIONS
       None.


SEE ALSO
       Function Definition Command


       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open  Group  Base
       Specifications Issue 6, Copyright (C) 2001-2003 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 .