binutils-gdb/gdb/contrib/expect-read1.c

/* Copyright (C) 2013-2021 Free Software Foundation, Inc.

   This file is part of GDB.

   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 <http://www.gnu.org/licenses/>.  */

/* RTLD_NEXT requires _GNU_SOURCE.  */
#define _GNU_SOURCE 1
#include <dlfcn.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>

ssize_t
read (int fd, void *buf, size_t count)
{
  static ssize_t (*read2) (int fd, void *buf, size_t count) = NULL;

  if (read2 == NULL)
    {
      unsetenv ("LD_PRELOAD");
      read2 = dlsym (RTLD_NEXT, "read");
    }

  if (count > 1 && isatty (fd) == 1)
    count = 1;

  return read2 (fd, buf, count);
}