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

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.
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 environ-
       ment 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 Exe-
       cution 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  Vari-
              ables  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 oper-
       ands 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 defini-
              tion, 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 fea-
       tures in this volume of  IEEE Std 1003.1-2001,  such  as  command  line
       editing.
       Since alias affects the current shell execution environment, it is gen-
       erally 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 trig-
       gered  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  pri-
       marily  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 out-
       put. 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 .

IEEE/The Open Group                  2003                            ALIAS(1P)