Clear the environment
#include <stdlib.h> int clearenv( void );
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The clearenv() function clears the environment area; no environment variables are defined immediately after the clearenv() call.
Note that clearenv() clears the following environment variables, which may then affect the operation of other library functions such as spawnp():
Clear the entire environment and set up a new TZ environment variable:
#include <stdio.h> #include <stdlib.h> int main( void ) { if( clearenv() != 0 ) { puts( "Unable to clear the environment" ); return EXIT_FAILURE; } setenv( "TZ", "EST5EDT", 0 ); return EXIT_SUCCESS; }
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |
The clearenv() function manipulates the environment pointed to by the global environ variable.
environ, errno, execl(), execle(), execlp(), execlpe(), execv(), execve(), execvp(), execvpe(), getenv(), putenv(), searchenv(), setenv(), spawn(), spawnl(), spawnle(), spawnlp(), spawnlpe(), spawnp(), spawnv(), spawnve(), spawnvp(), spawnvpe(), system(), unsetenv()