1UNALIAS(P)                 POSIX Programmer's Manual                UNALIAS(P)
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NAME

6       unalias - remove alias definitions
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SYNOPSIS

9       unalias alias-name...
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11       unalias -a
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DESCRIPTION

15       The  unalias  utility  shall  remove the definition for each alias name
16       specified. See Alias Substitution . The aliases shall be  removed  from
17       the  current  shell execution environment; see Shell Execution Environ‐
18       ment .
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OPTIONS

21       The unalias utility shall conform to the  Base  Definitions  volume  of
22       IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
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24       The following option shall be supported:
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26       -a     Remove  all  alias  definitions from the current shell execution
27              environment.
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29

OPERANDS

31       The following operand shall be supported:
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33       alias-name
34              The name of an alias to be removed.
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36

STDIN

38       Not used.
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INPUT FILES

41       None.
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ENVIRONMENT VARIABLES

44       The following environment variables shall affect the execution of  una‐
45       lias:
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47       LANG   Provide  a  default value for the internationalization variables
48              that are unset or null. (See  the  Base  Definitions  volume  of
49              IEEE Std 1003.1-2001,  Section  8.2,  Internationalization Vari‐
50              ables for the precedence of internationalization variables  used
51              to determine the values of locale categories.)
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53       LC_ALL If  set  to a non-empty string value, override the values of all
54              the other internationalization variables.
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56       LC_CTYPE
57              Determine the locale for  the  interpretation  of  sequences  of
58              bytes  of  text  data as characters (for example, single-byte as
59              opposed to multi-byte characters in arguments).
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61       LC_MESSAGES
62              Determine the locale that should be used to  affect  the  format
63              and contents of diagnostic messages written to standard error.
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65       NLSPATH
66              Determine the location of message catalogs for the processing of
67              LC_MESSAGES .
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ASYNCHRONOUS EVENTS

71       Default.
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STDOUT

74       Not used.
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STDERR

77       The standard error shall be used only for diagnostic messages.
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OUTPUT FILES

80       None.
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EXTENDED DESCRIPTION

83       None.
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EXIT STATUS

86       The following exit values shall be returned:
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88        0     Successful completion.
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90       >0     One of the alias-name operands specified  did  not  represent  a
91              valid alias definition, or an error occurred.
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93

CONSEQUENCES OF ERRORS

95       Default.
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97       The following sections are informative.
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APPLICATION USAGE

100       Since  unalias  affects  the current shell execution environment, it is
101       generally provided as a shell regular built-in.
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EXAMPLES

104       None.
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RATIONALE

107       The unalias description is based  on  that  from  historical  KornShell
108       implementations.  Known differences exist between that and the C shell.
109       The KornShell version was adopted to be consistent with all  the  other
110       KornShell features in this volume of IEEE Std 1003.1-2001, such as com‐
111       mand line editing.
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113       The -a option is the equivalent of the unalias * form of  the  C  shell
114       and  is  provided  to  address  security concerns about unknown aliases
115       entering the environment of a user (or application) through the  allow‐
116       able implementation-defined predefined alias route or as a result of an
117       ENV file. (Although unalias could be  used  to  simplify  the  "secure"
118       shell  script  shown  in the command rationale, it does not obviate the
119       need to quote all command names. An initial call to  unalias  -a  would
120       have to be quoted in case there was an alias for unalias.)
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FUTURE DIRECTIONS

123       None.
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SEE ALSO

126       Shell Command Language , alias
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129       Portions  of  this text are reprinted and reproduced in electronic form
130       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
131       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
132       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
133       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
134       event of any discrepancy between this version and the original IEEE and
135       The  Open Group Standard, the original IEEE and The Open Group Standard
136       is the referee document. The original Standard can be  obtained  online
137       at http://www.opengroup.org/unix/online.html .
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141IEEE/The Open Group                  2003                           UNALIAS(P)
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