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 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 cur-
       rent 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
", 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  Korn-
       Shell  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 Technol-
       ogy -- 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)