forkshell
if (forkshell(jp, NULL, FORK_NOJOB) == 0) {
if (forkshell(jp, cmd, mode) != 0)
forkshell(jp = makejob(n, 1), n, backgnd?FORK_BG:FORK_FG) == 0) {
if (forkshell(jp, lp->n,
if (forkshell(jp, n, FORK_NOJOB) == 0) {
int forkshell(struct job *, union node *, int);
if (forkshell(NULL, NULL, FORK_NOJOB) == 0) {