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

COPYRIGHT

       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 .