how to set environment variable when execle executes bash? -

here tried spawn bash using execle() , wanted set tmout environment new bash. worked well. see tmout environment variable new bash shell.

<example1> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>  int main(void) {     char *env[] = {"tmout=60", null};      execle("/bin/bash", "bash", null, env);     return 0; } 

but if same thing example2 use sudo, cannot see tmout environment variable new shell.

<example2> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>  int main(void) {     char *env[] = {"tmout=60", null};      execle("/bin/sudo", "sudo", "/bin/bash", null, null);     return 0; } 

i tried find example here. find information example1 above. not find information example2.

i tried following using putenv().

<example3> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>  int main(void) {     putenv("tmout=60");     execle("/bin/sudo", "sudo", "/bin/bash", null, null);     return 0; } 

but example3 didn't work. can please give me idea how set environment when use sudo this?