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Diffstat (limited to 'libio/filedoalloc.c')
-rw-r--r-- | libio/filedoalloc.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/libio/filedoalloc.c b/libio/filedoalloc.c new file mode 100644 index 0000000..8ab1738 --- /dev/null +++ b/libio/filedoalloc.c @@ -0,0 +1,103 @@ +/* +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; +} |