glibc/sysdeps/generic/sysd-stdio.c
1995-02-18 01:27:10 +00:00

190 lines
4.4 KiB
C

/* Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
/* Read N bytes into BUF from COOKIE. */
int
DEFUN(__stdio_read, (cookie, buf, n),
PTR cookie AND register char *buf AND register size_t n)
{
CONST int fd = (int) cookie;
#if defined (EINTR) && defined (EINTR_REPEAT)
int save = errno;
int nread;
try:;
errno = 0;
nread = __read (fd, buf, (int) n);
if (nread < 0)
{
if (errno == EINTR)
goto try;
return -1;
}
errno = save;
return nread;
#else /* No EINTR. */
return __read (fd, buf, n);
#endif
}
/* Write N bytes from BUF to COOKIE. */
int
DEFUN(__stdio_write, (cookie, buf, n),
PTR cookie AND register CONST char *buf AND register size_t n)
{
CONST int fd = (int) cookie;
register size_t written = 0;
while (n > 0)
{
int count = __write (fd, buf, (int) n);
if (count > 0)
{
buf += count;
written += count;
n -= count;
}
else if (count < 0
#if defined (EINTR) && defined (EINTR_REPEAT)
&& errno != EINTR
#endif
)
/* Write error. */
return -1;
}
return (int) written;
}
/* Move COOKIE's file position *POS bytes, according to WHENCE.
The new file position is stored in *POS.
Returns zero if successful, nonzero if not. */
int
DEFUN(__stdio_seek, (cookie, pos, whence),
PTR cookie AND fpos_t *pos AND int whence)
{
off_t new;
new = __lseek ((int) cookie, (off_t) *pos, whence);
if (new < 0)
return 1;
*pos = (fpos_t) new;
return 0;
}
/* Close COOKIE. */
int
DEFUN(__stdio_close, (cookie), PTR cookie)
{
return __close ((int) cookie);
}
/* Return the POSIX.1 file descriptor associated with COOKIE,
or -1 for errors. If COOKIE does not relate to any POSIX.1 file
descriptor, this should return -1 with errno set to EOPNOTSUPP. */
int
DEFUN(__stdio_fileno, (cookie), PTR cookie)
{
return (int) cookie;
}
/* Open the given file with the mode given in the __io_mode argument. */
int
DEFUN(__stdio_open, (filename, m, cookieptr),
CONST char *filename AND __io_mode m AND PTR *cookieptr)
{
int fd;
int mode;
if (m.__read && m.__write)
mode = O_RDWR;
else
mode = m.__read ? O_RDONLY : O_WRONLY;
if (m.__append)
mode |= O_APPEND;
if (m.__exclusive)
mode |= O_EXCL;
if (m.__truncate)
mode |= O_TRUNC;
if (m.__create)
fd = __open (filename, mode | O_CREAT,
S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
else
fd = __open (filename, mode);
if (fd < 0)
return -1;
*cookieptr = (PTR) fd;
return 0;
}
/* Open FILENAME with the mode in M. Use the same magic cookie
already in *COOKIEPTR if possible, closing the old cookie with CLOSEFN. */
int
DEFUN(__stdio_reopen, (filename, m, cookieptr),
CONST char *filename AND __io_mode m AND
PTR *cookieptr AND __io_close_fn closefn)
{
PTR newcookie;
/* We leave the old descriptor open while we open the file.
That way ``freopen ("/dev/stdin", "r", stdin)'' works. */
if (__stdio_open (filename, m, &newcookie))
{
if (errno == ENFILE || errno == EMFILE)
{
/* We are out of file descriptors. Try closing the old one and
retrying the open. */
(void) (*closefn) (*cookieptr);
if (__stdio_open (filename, m, &newcookie))
return -1;
}
}
if (newcookie != *cookieptr)
{
if (closefn != __stdio_close ||
/* Try to move the descriptor to the desired one. */
__dup2 ((int) newcookie, (int) *cookieptr) < 0)
/* Didn't work. Give the caller the new cookie. */
*cookieptr = newcookie;
}
return 0;
}