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-rw-r--r--libio/iosetvbuf.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/libio/iosetvbuf.c b/libio/iosetvbuf.c
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+/*
+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. */
+
+#include "libioP.h"
+
+#define _IOFBF 0 /* Fully buffered. */
+#define _IOLBF 1 /* Line buffered. */
+#define _IONBF 2 /* No buffering. */
+
+int
+_IO_setvbuf (fp, buf, mode, size)
+ _IO_FILE* fp;
+ char* buf;
+ int mode;
+ _IO_size_t size;
+{
+ CHECK_FILE (fp, EOF);
+ switch (mode)
+ {
+ case _IOFBF:
+ fp->_IO_file_flags &= ~_IO_LINE_BUF;
+ if (buf == NULL)
+ {
+ if (fp->_IO_buf_base == NULL)
+ {
+ /* There is no flag to distinguish between "fully buffered
+ mode has been explicitly set" as opposed to "line
+ buffering has not been explicitly set". In both
+ cases, _IO_LINE_BUF is off. If this is a tty, and
+ _IO_filedoalloc later gets called, it cannot know if
+ it should set the _IO_LINE_BUF flag (because that is
+ the default), or not (because we have explicitly asked
+ for fully buffered mode). So we make sure a buffer
+ gets allocated now, and explicitly turn off line
+ buffering.
+
+ A possibly cleaner alternative would be to add an
+ extra flag, but then flags are a finite resource. */
+ if (_IO_DOALLOCATE (fp) < 0)
+ return EOF;
+ fp->_IO_file_flags &= ~_IO_LINE_BUF;
+ }
+ return 0;
+ }
+ break;
+ case _IOLBF:
+ fp->_IO_file_flags |= _IO_LINE_BUF;
+ if (buf == NULL)
+ return 0;
+ break;
+ case _IONBF:
+ buf = NULL;
+ size = 0;
+ break;
+ default:
+ return EOF;
+ }
+ return _IO_SETBUF (fp, buf, size) == NULL ? EOF : 0;
+}