1  /* Truncate a file given by name.  Generic POSIX.1 version.
       2     Copyright (C) 1995-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <sys/types.h>
      20  #include <errno.h>
      21  #include <unistd.h>
      22  #include <fcntl.h>
      23  
      24  /* Truncate PATH to LENGTH bytes.  */
      25  int
      26  __truncate (const char *path, off_t length)
      27  {
      28    int fd, ret, save;
      29  
      30    fd = __open (path, O_WRONLY | (length == 0 ? O_TRUNC : 0));
      31    if (fd < 0)
      32      return -1;
      33  
      34    if (length == 0)
      35      ret = 0;
      36    else
      37      ret = __ftruncate (fd, length);
      38    save = errno;
      39    (void) __close (fd);
      40    if (ret < 0)
      41      __set_errno (save);
      42    return ret;
      43  }
      44  weak_alias (__truncate, truncate)