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  man pages->Tru64 Unix man pages -> putenv (3)              



NAME    [Toc]    [Back]

       putenv - Sets an environment variable

SYNOPSIS    [Toc]    [Back]

       #include <stdlib.h>

       int putenv(
               const char *string );

       The  following  syntax is for XSH5.0-compliant interfaces:
       #include <stdlib.h>

       int putenv(
               char *string );

LIBRARY    [Toc]    [Back]

       Standard C Library (libc)

STANDARDS    [Toc]    [Back]

       Interfaces documented on this reference  page  conform  to
       industry standards as follows:

       putenv(): XSH4.0, XSH4.2, XSH5.0, POSIX.1

       Refer to the standards(5) reference page for more information
 about industry standards and associated tags.

PARAMETERS    [Toc]    [Back]

       Points to a name=value string.

DESCRIPTION    [Toc]    [Back]

       The putenv() function sets the  value  of  an  environment
       variable by altering an existing variable or by creating a
       new one. The new environment variable  remains  in  effect
       even after the program setting it is exited.

       The  string  parameter  points  to  a  string  of the form
       "name=value", where name is the environment  variable  and
       value is the new value for it.

NOTES    [Toc]    [Back]

       The  putenv()  function  manipulates  the environ external
       variable, and it can  be  used  in  conjunction  with  the
       getenv()  function.  However,  the  third parameter to the
       main function (the environment pointer) is not changed.

       The  putenv()  function  uses  the  malloc()  function  to
       enlarge the environment.

       A  potential  error  is to call putenv() with an automatic
       variable as the argument and then exit the  calling  function
 while string is still part of the environment.

RETURN VALUES    [Toc]    [Back]

       Upon  successful  completion,  a  value  of  0  (zero)  is
       returned. If the malloc() function  is  unable  to  obtain
       sufficient  space  to expand the environment, the putenv()
       function returns a nonzero value.

SEE ALSO    [Toc]    [Back]

       Functions: clearenv(3), exec(2), getenv(3), malloc(3)

       Standards: standards(5)

[ Back ]
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