/* * Unix routine to do an "fopen" on file descriptor * The mode has to be repeated because you can't query its * status */#include	<stdio.h>#include	<errno.h>FILE *fdopen(fd, mode)	register char *mode;{	register FILE *iop;	FILE *_findiop();	if ((iop = _findiop()) == NULL)		return(NULL);	iop->_cnt = 0;	iop->_file = fd;	switch (*mode) {	case 'r':		iop->_flag |= _IOREAD;		break;	case 'a':		lseek(fd, 0L, 2);		/* No break */	case 'w':		iop->_flag |= _IOWRT;		break;	default:		return(NULL);	}	if (mode[1] == '+') {		iop->_flag &= ~(_IOREAD|_IOWRT);		iop->_flag |= _IORW;	}	return(iop);}