SysIII/usr/src/lib/libc/pdp11/stdio/endopen.c

/*LINTLIBRARY*/
#include	<stdio.h>
#include	<errno.h>

FILE *
_endopen (file, mode, iop)
char *file, *mode;
register FILE *iop;
{
	extern int errno;
	register int rw, f;

	if (iop == NULL)
		return NULL;

	rw = mode[1] == '+';

	switch (*mode) {

	case 'w':
		f = create (file, rw);
		break;

	case 'a':
		if ((f = open (file, rw? 2: 1)) < 0) {
			if (errno == ENOENT)
				f = create (file, rw);
		}
		lseek (f, 0L, 2);
		break;

	case 'r':
		f = open (file, rw? 2: 0);
		break;

	default:
		return NULL;
	}

	if (f < 0)
		return NULL;

	iop->_cnt = 0;
	iop->_file = f;

	if (rw)
		iop->_flag |= _IORW;
	else if (*mode == 'r')
		iop->_flag |= _IOREAD;
	else
		iop->_flag |= _IOWRT;

	return iop;
}

static int
create (file, rw)
register char *file;
int rw;
{
	register int m, f;

	if (rw) {
		m = umask (0);
		f = creat (file, 0666);
		if (f >= 0) {
			close (f);
			f = open (file, 2);
			chmod (file, 0666 & ~m);
		}
		umask (m);
	} else
		f = creat (file, 0666);
	
	return f;
}