~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 MySQL AB

   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; version 2 of the License.

   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, write to the Free Software

   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include "mysys/mysys_priv.h"

#include "mysys/mysys_err.h"

#include <mystrings/m_string.h>

#include <errno.h>

#ifdef HAVE_REALPATH

#include <sys/param.h>

#include <sys/stat.h>

#endif

/*

  Reads the content of a symbolic link

  If the file is not a symbolic link, return the original file name in to.

  RETURN

    0  If filename was a symlink,    (to will be set to value of symlink)

    1  If filename was a normal file (to will be set to filename)

   -1  on error.

*/

int my_readlink(char *to, const char *filename, myf MyFlags)

{

#ifndef HAVE_READLINK

  strcpy(to,filename);

  return 1;

#else

  int result=0;

  int length;

  if ((length=readlink(filename, to, FN_REFLEN-1)) < 0)

  {

    /* Don't give an error if this wasn't a symlink */

    if ((my_errno=errno) == EINVAL)

    {

      result= 1;

      strcpy(to,filename);

    }

    else

    {

      if (MyFlags & MY_WME)

	my_error(EE_CANT_READLINK, MYF(0), filename, errno);

      result= -1;

    }

  }

  else

    to[length]=0;

  return(result);

#endif /* HAVE_READLINK */

}

/* Create a symbolic link */

int my_symlink(const char *content, const char *linkname, myf MyFlags)

{

#ifndef HAVE_READLINK

  return 0;

#else

  int result;

  result= 0;

  if (symlink(content, linkname))

  {

    result= -1;

    my_errno=errno;

    if (MyFlags & MY_WME)

      my_error(EE_CANT_SYMLINK, MYF(0), linkname, content, errno);

  }

  else if ((MyFlags & MY_SYNC_DIR) && my_sync_dir_by_file(linkname, MyFlags))

    result= -1;

  return(result);

#endif /* HAVE_READLINK */

}

/*

  Resolve all symbolic links in path

  'to' may be equal to 'filename'

  Because purify gives a lot of UMR errors when using realpath(),

  this code is disabled when using purify.

  If MY_RESOLVE_LINK is given, only do realpath if the file is a link.

*/

#if defined(SCO)

#define BUFF_LEN 4097

#elif defined(MAXPATHLEN)

#define BUFF_LEN MAXPATHLEN

#else

#define BUFF_LEN FN_LEN

#endif

int my_realpath(char *to, const char *filename, myf MyFlags)

{

#if defined(HAVE_REALPATH) &&  !defined(HAVE_BROKEN_REALPATH)

  int result=0;

  char buff[BUFF_LEN];

  struct stat stat_buff;

  if (!(MyFlags & MY_RESOLVE_LINK) ||

      (!lstat(filename,&stat_buff) && S_ISLNK(stat_buff.st_mode)))

  {

    char *ptr;

    if ((ptr=realpath(filename,buff)))

    {

      strncpy(to,ptr,FN_REFLEN-1);

    }

    else

    {

      /*

	Realpath didn't work;  Use my_load_path() which is a poor substitute

	original name but will at least be able to resolve paths that starts

	with '.'.

      */

      my_errno=errno;

      if (MyFlags & MY_WME)

	my_error(EE_REALPATH, MYF(0), filename, my_errno);

      my_load_path(to, filename, NULL);

      result= -1;

    }

  }

  return(result);

#else

  my_load_path(to, filename, NULL);

  return 0;

#endif

}