1 files changed, 80 insertions, 0 deletions
diff --git a/libio/iosetvbuf.c b/libio/iosetvbuf.c
new file mode 100644
index 0000000000..316179e330
--- /dev/null
+++ b/libio/iosetvbuf.c
@@ -0,0 +1,80 @@
+/*
+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;
+}