Man Alias en anglais
ALIAS(P)                   POSIX Programmer's Manual                  ALIAS(P)



 

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
       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 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(P)