clearenv -- Delete Environment Variables

SYNOPSIS
#include <env.h>
int clearenv(void);
DESCRIPTION
clearenv
deletes the environment-variable list for a process. Only
program-scope environment variables are affected.
RETURN VALUE
clearenv
returns 0 if it is successful and - 1 if it
is not successful.
CAUTION
A copy of the environ
pointer may not be valid after a call is
made to clearenv
.
EXAMPLE
The following code fragment illustrates the use of clearenv
:
/* This example requires compilation with the posix option */
/* to execute successfully. */
#include <stdlib.h>
#include <stdio.h>
extern char **environ;
int count_env() {
int num;
for (num=0; environ[num] !=NULL; num++);
return num;
}
.
.
.
printf("There are %d environment variablesn", count_env());
if (clearenv() !=0)
perror("clearenv() error");
else {
printf("Now there are %d environment variablesn", count_env());
}
.
.
.
RELATED FUNCTIONS
getenv
, setenv
SEE ALSO