Fill in the blanks.

include include #include include int main (void) pid.t childpid; int fd [2]; ) setup a pipe */ perror (" Failed to setup pipeline"); return 1: * fork a child * perror (" Failed to fork a child"); return 1; )/*env is the child / perror (" Failed to redirect stdout of env"); perror (" Failed to close extra pipe descriptors on env"); execl perror("Failed to exec env); else if ( ) /*close unused file descriptor */ else execute env return 1; grep is the parent else f else perror(" Failed to redirect stdin of grep"); perror(" Failed to close extra pipe file descriptors on grep"); execl ) *execute "grep HOME" perror(" Failed to exec grep"); return 1: Asg red o.c