| /* |
| Copyright (C) 1993 Free Software Foundation |
| |
| This file is part of the GNU IO Library. This library is free |
| software; you can redistribute it and/or modify it under the |
| terms of the GNU General Public License as published by the |
| Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| This 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 General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this library; see the file COPYING. If not, write to the Free |
| Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| |
| As a special exception, if you link this library with files |
| compiled with a GNU compiler to produce an executable, this does not cause |
| the resulting executable to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why |
| the executable file might be covered by the GNU General Public License. */ |
| |
| /* |
| * Copyright (c) 1990 The Regents of the University of California. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms are permitted |
| * provided that the above copyright notice and this paragraph are |
| * duplicated in all such forms and that any documentation, |
| * advertising materials, and other materials related to such |
| * distribution and use acknowledge that the software was developed |
| * by the University of California, Berkeley. The name of the |
| * University may not be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| */ |
| |
| /* Modified for GNU iostream by Per Bothner 1991, 1992. */ |
| |
| #define _POSIX_SOURCE |
| #include "libioP.h" |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #ifdef __STDC__ |
| #include <stdlib.h> |
| #endif |
| |
| /* If this function pointer is non-zero, we should call it. |
| It's supposed to make sure _IO_cleanup gets called on exit. |
| We call it from _IO_file_doallocate, since that is likely |
| to get called by any program that does buffered I/O. */ |
| void (*_IO_cleanup_registration_needed)(); |
| |
| /* |
| * Allocate a file buffer, or switch to unbuffered I/O. |
| * Per the ANSI C standard, ALL tty devices default to line buffered. |
| * |
| * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek |
| * optimisation) right after the _fstat() that finds the buffer size. |
| */ |
| |
| int |
| DEFUN(_IO_file_doallocate, (fp), |
| register _IO_FILE *fp) |
| { |
| register _IO_size_t size; |
| int couldbetty; |
| register char *p; |
| struct stat st; |
| |
| if (_IO_cleanup_registration_needed) |
| (*_IO_cleanup_registration_needed)(); |
| |
| if (fp->_fileno < 0 || _IO_SYSSTAT (fp, &st) < 0) |
| { |
| couldbetty = 0; |
| size = _IO_BUFSIZ; |
| #if 0 |
| /* do not try to optimise fseek() */ |
| fp->_flags |= __SNPT; |
| #endif |
| } |
| else |
| { |
| couldbetty = S_ISCHR(st.st_mode); |
| #if _IO_HAVE_ST_BLKSIZE |
| size = st.st_blksize <= 0 ? _IO_BUFSIZ : st.st_blksize; |
| #else |
| size = _IO_BUFSIZ; |
| #endif |
| } |
| p = ALLOC_BUF(size); |
| if (p == NULL) |
| return EOF; |
| _IO_setb(fp, p, p+size, 1); |
| if (couldbetty && isatty(fp->_fileno)) |
| fp->_flags |= _IO_LINE_BUF; |
| return 1; |
| } |