c - How to execute ./process 2>&1 | tee log.txt with execvp -

i try write process controller. should restart process again every time fails. start process following terminal command:

./process 2>&1 | tee log.txt 

now want execute command execvp:

int main() {     int status;      while(1) {         pid = fork();         char* const argv[4] = {"2>&1", "tee", "log.txt", null};          if(pid == 0) {             // make child process ./process             if(execvp("./process", argv) {                 perror("execvp");                 exit(1);             }         }         else if(pid > 0) {             sleep(3);             // wait ./process return             waitpid(pid, &status, 0);         }     } } 

this example program doesn't fail , ./process starts 2>&1 | tee log.txt not executed or @ least log file doesn't appear.

any suggestions?