gzdopen
file = gzdopen(fileno(stdin), "rb");
file = gzdopen(fileno(stdout), outmode);
file = gzdopen(fileno(stdout), outmode);
ZEXTERN gzFile ZEXPORT gzdopen(int fd, const char *mode);
zfp = gzdopen(STDIN_FILENO, "rb");
if ((in = gzdopen(pipefd[0], "r")) == NULL) {
gzf = gzdopen(dup(prep_fd), "a");
gzf = gzdopen(dup(rs6000_fd), "a");
gzf = gzdopen(dup(bebox_fd), "a");
ZEXTERN gzFile ZEXPORT gzdopen(int, const char *);
(gzbufdesc = gzdopen(f->fd, "r")) == NULL)