my_copy.cc

/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   Without limiting anything contained in the foregoing, this file,
   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
   http://oss.oracle.com/licenses/universal-foss-exception.

   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, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/**
  @file mysys/my_copy.cc
*/

#include "my_config.h"

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>

#include "my_dir.h" /* for stat */
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_io.h"
#include "my_macros.h"
#include "my_sys.h"
#include "my_thread_local.h"
#include "mysys_err.h"

#ifndef _WIN32
#include <utime.h>
#else
#include <sys/utime.h>
#endif

/*
  int my_copy(const char *from, const char *to, myf MyFlags)

  NOTES
    Ordinary ownership and accesstimes are copied from 'from-file'
    If MyFlags & MY_HOLD_ORIGINAL_MODES is set and to-file exists then
    the modes of to-file isn't changed
    If MyFlags & MY_DONT_OVERWRITE_FILE is set, we will give an error
    if the file existed.

  WARNING
    Don't set MY_FNABP or MY_NABP bits on when calling this function !

  RETURN
    0	ok
    #	Error

*/

int my_copy(const char *from, const char *to, myf MyFlags) {
  size_t Count;
  bool new_file_stat = 0; /* 1 if we could stat "to" */
  int create_flag;
  File from_file, to_file;
  uchar buff[IO_SIZE];
  MY_STAT stat_buff, new_stat_buff;
  DBUG_ENTER("my_copy");
  DBUG_PRINT("my", ("from %s to %s MyFlags %d", from, to, MyFlags));

  from_file = to_file = -1;
  memset(&new_stat_buff, 0, sizeof(MY_STAT));
  DBUG_ASSERT(!(MyFlags & (MY_FNABP | MY_NABP))); /* for my_read/my_write */
  if (MyFlags & MY_HOLD_ORIGINAL_MODES)           /* Copy stat if possible */
    new_file_stat = my_stat((char *)to, &new_stat_buff, MYF(0)) != nullptr;

  if ((from_file = my_open(from, O_RDONLY, MyFlags)) >= 0) {
    if (!my_stat(from, &stat_buff, MyFlags)) {
      set_my_errno(errno);
      goto err;
    }
    if (MyFlags & MY_HOLD_ORIGINAL_MODES && new_file_stat)
      stat_buff = new_stat_buff;
    create_flag = (MyFlags & MY_DONT_OVERWRITE_FILE) ? O_EXCL : O_TRUNC;

    if ((to_file = my_create(to, (int)stat_buff.st_mode, O_WRONLY | create_flag,
                             MyFlags)) < 0)
      goto err;

    while ((Count = my_read(from_file, buff, sizeof(buff), MyFlags)) != 0) {
      if (Count == (uint)-1 ||
          my_write(to_file, buff, Count, MYF(MyFlags | MY_NABP)))
        goto err;
    }

    /* sync the destination file */
    if (MyFlags & MY_SYNC) {
      if (my_sync(to_file, MyFlags)) goto err;
    }

    if (my_close(from_file, MyFlags) | my_close(to_file, MyFlags))
      DBUG_RETURN(-1); /* Error on close */

    /* Reinitialize closed fd, so they won't be closed again. */
    from_file = -1;
    to_file = -1;

    /* Copy modes if possible */

    if (MyFlags & MY_HOLD_ORIGINAL_MODES && !new_file_stat)
      DBUG_RETURN(0); /* File copyed but not stat */
    /* Copy modes */
    if (chmod(to, stat_buff.st_mode & 07777)) {
      set_my_errno(errno);
      if (MyFlags & (MY_FAE + MY_WME)) {
        char errbuf[MYSYS_STRERROR_SIZE];
        my_error(EE_CHANGE_PERMISSIONS, MYF(0), from, errno,
                 my_strerror(errbuf, sizeof(errbuf), errno));
      }
      goto err;
    }
#if !defined(_WIN32)
    /* Copy ownership */
    if (chown(to, stat_buff.st_uid, stat_buff.st_gid)) {
      set_my_errno(errno);
      if (MyFlags & (MY_FAE + MY_WME)) {
        char errbuf[MYSYS_STRERROR_SIZE];
        my_error(EE_CHANGE_OWNERSHIP, MYF(0), from, errno,
                 my_strerror(errbuf, sizeof(errbuf), errno));
      }
      goto err;
    }
#endif

    if (MyFlags & MY_COPYTIME) {
      struct utimbuf timep;
      timep.actime = stat_buff.st_atime;
      timep.modtime = stat_buff.st_mtime;
      (void)utime((char *)to, &timep); /* last accessed and modified times */
    }

    DBUG_RETURN(0);
  }

err:
  if (from_file >= 0) (void)my_close(from_file, MyFlags);
  if (to_file >= 0) {
    (void)my_close(to_file, MyFlags);
    /* attempt to delete the to-file we've partially written */
    (void)my_delete(to, MyFlags);
  }
  DBUG_RETURN(-1);
} /* my_copy */