sl@0: /* MAKEBUF.C
sl@0:  *
sl@0:  * Portions Copyright (c) 1990-1999 Nokia Corporation and/or its subsidiary(-ies).
sl@0:  * All rights reserved.
sl@0:  */
sl@0: 
sl@0: /* No user fns here.  Pesch 15apr92. */
sl@0: 
sl@0: /*
sl@0:  * Copyright (c) 1990 The Regents of the University of California.
sl@0:  * All rights reserved.
sl@0:  *
sl@0:  * Redistribution and use in source and binary forms are permitted
sl@0:  * provided that the above copyright notice and this paragraph are
sl@0:  * duplicated in all such forms and that any documentation,
sl@0:  * advertising materials, and other materials related to such
sl@0:  * distribution and use acknowledge that the software was developed
sl@0:  * by the University of California, Berkeley.  The name of the
sl@0:  * University may not be used to endorse or promote products derived
sl@0:  * from this software without specific prior written permission.
sl@0:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
sl@0:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
sl@0:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
sl@0:  */
sl@0: 
sl@0: #include <stdio_r.h>
sl@0: #include <stdlib_r.h>
sl@0: #include <sys/stat.h>
sl@0: #include <sys/types.h>
sl@0: #include <sys/unistd.h>
sl@0: 
sl@0: #include "LOCAL.H"
sl@0: 
sl@0: /*
sl@0:  * Allocate a file buffer, or switch to unbuffered I/O.
sl@0:  * Per the ANSI C standard, ALL tty devices default to line buffered.
sl@0:  *
sl@0:  * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek
sl@0:  * optimization) right after the _fstat() that finds the buffer size.
sl@0:  */
sl@0: 
sl@0: void
sl@0: __smakebuf (register FILE *fp)
sl@0: {
sl@0:   register size_t size, couldbetty;
sl@0:   register void* p;
sl@0:   struct stat st;
sl@0: 
sl@0:   if (fp->_flags & __SNBF)
sl@0:     {
sl@0:       fp->_bf._base = fp->_p = fp->_nbuf;
sl@0:       fp->_bf._size = 1;
sl@0:       return;
sl@0:     }
sl@0:   if (fp->_file < 0 || _fstat_r (fp->_data, fp->_file, &st) < 0)
sl@0:     {
sl@0:       couldbetty = 0;
sl@0:       size = BUFSIZ;
sl@0:       /* do not try to optimise fseek() */
sl@0:       fp->_flags |= __SNPT;
sl@0:     }
sl@0:   else
sl@0:     {
sl@0:       couldbetty = (st.st_mode & S_IFMT) == S_IFCHR;
sl@0:       size = st.st_blksize <= 0 ? BUFSIZ : st.st_blksize;
sl@0:       /*
sl@0:        * Optimize fseek() only if it is a regular file.
sl@0:        * (The test for __sseek is mainly paranoia.)
sl@0:        */
sl@0:       if ((st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek)
sl@0: 	{
sl@0: 	  fp->_flags |= __SOPT;
sl@0: 	  fp->_blksize = st.st_blksize;
sl@0: 	}
sl@0:       else
sl@0: 	fp->_flags |= __SNPT;
sl@0:     }
sl@0:   if ((p = _malloc_r (fp->_data, size)) == NULL)
sl@0:     {
sl@0:       fp->_flags |= __SNBF;
sl@0:       fp->_bf._base = fp->_p = fp->_nbuf;
sl@0:       fp->_bf._size = 1;
sl@0:     }
sl@0:   else
sl@0:     {
sl@0:       fp->_data->__cleanup = _cleanup_r;
sl@0:       fp->_flags |= __SMBF;
sl@0:       fp->_bf._base = fp->_p = (unsigned char *) p;
sl@0:       fp->_bf._size = size;
sl@0:       if (couldbetty && isatty (fp->_file))
sl@0: 	fp->_flags |= __SLBF;
sl@0:     }
sl@0: }