info/dribble.c

/* dribble.c -- dribble files for Info.

   Copyright 1993-2026 Free Software Foundation, Inc.

   This program 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 3 of the License, or
   (at your option) any later version.

   This program 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 program.  If not, see <https://www.gnu.org/licenses/>.

   Originally written by Brian Fox. */

#include "info.h"
#include "dribble.h"

/* When non-zero, it is a stream to write all input characters to for the
   duration of this info session. */
FILE *info_dribble_file = NULL;

/* Open a dribble file named NAME, perhaps closing an already open one.
   This sets the global variable INFO_DRIBBLE_FILE to the open stream. */
void
open_dribble_file (char *name)
{
  /* Perhaps close existing dribble file. */
  close_dribble_file ();

  /* Keystrokes can be non-printable characters, so we need binary I/O.  */
  info_dribble_file = fopen (name, FOPEN_WBIN);

  if (info_dribble_file)
    setvbuf (info_dribble_file, NULL, _IONBF, 1);
}

/* If there is a dribble file already open, close it. */
void
close_dribble_file (void)
{
  if (info_dribble_file)
    {
      fflush (info_dribble_file);
      fclose (info_dribble_file);
      info_dribble_file = NULL;
    }
}

/* Write some output to our existing dribble file. */
void
dribble (unsigned char byte)
{
  if (info_dribble_file)
    fwrite (&byte, sizeof (unsigned char), 1, info_dribble_file);
}