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       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

       export — set the export attribute for variables

SYNOPSIS

       export name[=word]...

       export −p

DESCRIPTION

       The  shell shall give the export attribute to the variables corresponding to the specified
       names, which shall cause them to be in the environment of subsequently executed  commands.
       If  the  name of a variable is followed by =word, then the value of that variable shall be
       set to word.

       The export special built-in shall support the Base  Definitions  volume  of  POSIX.1‐2008,
       Section 12.2, Utility Syntax Guidelines.

       When  −p  is  specified, export shall write to the standard output the names and values of
       all exported variables, in the following format:

           "export %s=%s\n", <name>, <value>

       if name is set, and:

           "export %s\n", <name>

       if name is unset.

       The shell shall format the output, including the proper use of  quoting,  so  that  it  is
       suitable  for  reinput  to  the shell as commands that achieve the same exporting results,
       except:

        1. Read-only variables with values cannot be reset.

        2. Variables that were unset at the time they were output need not be reset to the  unset
           state  if a value is assigned to the variable between the time the state was saved and
           the time at which the saved output is reinput to the shell.

       When no arguments are given,  the  results  are  unspecified.  If  a  variable  assignment
       precedes  the command name of export but that variable is not also listed as an operand of
       export, then that variable shall be set in the current shell execution  environment  after
       the  completion  of  the  export  command,  but it is unspecified whether that variable is
       marked for export.

OPTIONS

       See the DESCRIPTION.

OPERANDS

       See the DESCRIPTION.

STDIN

       Not used.

INPUT FILES

       None.

ENVIRONMENT VARIABLES

       None.

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       See the DESCRIPTION.

STDERR S

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       Zero.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       None.

EXAMPLES

       Export PWD and HOME variables:

           export PWD HOME

       Set and export the PATH variable:

           export PATH=/local/bin:$PATH

       Save and restore all exported variables:

           export −p > temp-file
           unset a lot of variables
           ... processing
           . temp-file

RATIONALE

       Some historical shells use the no-argument case as the functional equivalent  of  what  is
       required  here  with  −p.   This feature was left unspecified because it is not historical
       practice in all shells, and some scripts may rely on the now-unspecified results on  their
       implementations.  Attempts  to specify the −p output as the default case were unsuccessful
       in achieving consensus.  The −p option was added to allow portable access  to  the  values
       that can be saved and then later restored using; for example, a dot script.

FUTURE DIRECTIONS

       None.

SEE ALSO

       Section 2.14, Special Built-In Utilities

       The Base Definitions volume of POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1, 2013 Edition, Standard for Information Technology  --  Portable  Operating  System
       Interface  (POSIX),  The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical  Corrigendum  1  applied.)  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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most  likely  to  have
       been  introduced  during  the conversion of the source files to man page format. To report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .