CLEARENV(V)                                           CLEARENV(V)



NAME
       clearenv - clear the environment

SYNOPSIS
       #include <stdlib.h>

       int clearenv(v);

DESCRIPTION
       The  clearenv()  function  clears  the  environment of all
       name-value pairs.


RETURN VALUE
       The clearenv() function returns zero  on  success,  and  a
       non-zero value on failure.


AVAILABILITY
       Not in libc4, libc5. In glibc since glibc 2.0.


CONFORMING TO
       Various  Unix  variants  (DGUX,  HPUX, QNX, ...).  POSIX.9
       (bindings for FORTRAN77).   POSIX.1-1996  did  not  accept
       clearenv()  and  putenv(), but changed its mind and sched-
       uled these functions for some later issue of this standard
       (cf.  B.4.6.1).  However,  SUSv3  only  adds putenv(), and
       rejected clearenv().


NOTES
       Used in security-conscious applications. If it is unavail-
       able the assignment
                   environ = NULL;
       will probably do.

SEE ALSO
       getenv(v), putenv(v), setenv(v), unsetenv(v), environ(n)




Linux Programmer's Manual   2001-10-17                CLEARENV(V)