redirect_dup2    2771 process.c                  ret = redirect_dup2(pairs[j].oldfd, pairs[j].newfd); /* async-signal-safe */
redirect_dup2    2808 process.c                  ret = redirect_dup2(pairs[i].oldfd, extra_fd); /* async-signal-safe */
redirect_dup2    2819 process.c                  ret = redirect_dup2(pairs[j].oldfd, pairs[j].newfd); /* async-signal-safe */
redirect_dup2    2876 process.c              ret = redirect_dup2(oldfd, newfd); /* async-signal-safe */