Man Export en anglais
EXPORT(P)                  POSIX Programmer's Manual                 EXPORT(P)



 

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 correspond-
       ing to the specified names, which shall cause them to be in  the  envi-
       ronment 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 IEEE Std 1003.1-2001, 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", , 

       if name is set, and:


              "export %s\n", 

       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.

 

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


       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-fileunset 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 implemen-
       tations. 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


       Special Built-In Utilities

 

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                            EXPORT(P)