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seta75D 7c4988eac0 Init
2021-10-11 19:38:01 -03:00

131 lines
2.9 KiB
C
Executable File

/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T */
/* The copyright notice above does not evidence any */
/* actual or intended publication of such source code. */
#ident "@(#)fopen.c 1.15 93/11/15 SMI" /* SVr4.0 1.20 */
/*LINTLIBRARY*/
#include "synonyms.h"
#include <stdio.h>
#include "stdiom.h"
#include <fcntl.h>
#include <unistd.h>
#include <limits.h>
#include <thread.h>
#include <synch.h>
#include <mtlib.h>
static FILE *
_endopen(name, type, iop) /* open UNIX file name, associate with iop */
const char *name;
const char *type;
register FILE *iop;
{
register int oflag, plus, fd;
#ifdef _REENTRANT
rmutex_t *lk;
#endif _REENTRANT
if (iop == 0)
return 0;
switch (type[0])
{
default:
return 0;
case 'r':
oflag = O_RDONLY;
break;
case 'w':
oflag = O_WRONLY | O_TRUNC | O_CREAT;
break;
case 'a':
oflag = O_WRONLY | O_APPEND | O_CREAT;
break;
}
/* UNIX ignores 'b' and treats text and binary the same */
if ((plus = type[1]) == 'b')
plus = type[2];
if (plus == '+')
oflag = (oflag & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
if ((fd = open(name, oflag, 0666)) < 0)
return 0;
if (fd > UCHAR_MAX) {
(void)close(fd);
return 0;
}
iop->_file = (unsigned char)fd; /* assume fits in unsigned char */
FLOCKFILE(lk, iop); /* this lock may be unnecessary */
if (plus == '+')
iop->_flag = _IORW;
else if (type[0] == 'r')
iop->_flag = _IOREAD;
else
iop->_flag = _IOWRT;
FUNLOCKFILE(lk);
if (oflag == (O_WRONLY | O_APPEND | O_CREAT)) /* type == "a" */
if (lseek(fd, 0L, 2) < 0L) {
close(fd);
return NULL;
}
return iop;
}
FILE *
fopen(name, type) /* open name, return new stream */
const char *name;
const char *type;
{
#ifdef _REENTRANT
register FILE *iop;
register FILE *rc;
iop = _findiop();
/*
* Note that iop is not locked here, since no other thread could
* possibly call _endopen with the same iop at this point.
*/
rc = _endopen(name, type, iop);
if (rc == 0)
iop->_flag = 0; /* release iop */
return rc;
#else
return _endopen(name, type, _findiop());
#endif _REENTRANT
}
FILE *
freopen(name, type, iop) /* open name, associate with existing stream */
const char *name;
const char *type;
FILE *iop;
{
#ifdef _REENTRANT
FILE *rc;
rmutex_t *lk;
FLOCKFILE(lk, iop);
/*
* there may be concurrent calls to reopen the same stream - need
* to make freopen() atomic
*/
(void)close_fd(iop);
/* new function to do everything that fclose() does, except */
/* to release the iop - this cannot yet be released since */
/* _endopen() is yet to be called on this iop */
rc = _endopen(name, type, iop);
if (rc == 0)
iop->_flag = 0; /* release iop */
FUNLOCKFILE(lk);
return rc;
#else
(void)fclose(iop);
return _endopen(name, type, iop);
#endif _REENTRANT
}