StdLib/LibC/StdLib/realpath.c

   1 /** @file
   2   Implement the realpath function.
   3
   4   Copyright (c) 2011, Intel Corporation
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include <LibConfig.h>
  16 #include <Library/BaseLib.h>
  17 #include <Library/PathLib.h>
  18 #include <Library/MemoryAllocationLib.h>
  19 #include <errno.h>
  20
  21 /**
  22   The realpath() function shall derive, from the pathname pointed to by
  23   file_name, an absolute pathname that names the same file, whose resolution
  24   does not involve '.', '..', or symbolic links. The generated pathname shall
  25   be stored as a null-terminated string, up to a maximum of {PATH_MAX} bytes,
  26   in the buffer pointed to by resolved_name.
  27
  28   If resolved_name is a null pointer, the behavior of realpath() is
  29   implementation-defined.
  30
  31   @param[in] file_name            The filename to convert.
  32   @param[in,out] resolved_name    The resultant name.
  33
  34   @retval NULL                    An error occured.
  35   @return resolved_name.
  36 **/
  37 char *
  38 realpath(
  39   char *file_name,
  40   char *resolved_name
  41   )
  42 {
  43   CHAR16 *Temp;
  44   if (file_name == NULL || resolved_name == NULL) {
  45     errno = EINVAL;
  46     return (NULL);
  47   }
  48   Temp = AllocateZeroPool((1+AsciiStrLen(file_name))*sizeof(CHAR16));
  49   if (Temp == NULL) {
  50     errno = ENOMEM;
  51     return (NULL);
  52   }
  53   AsciiStrToUnicodeStr(file_name, Temp);
  54   PathCleanUpDirectories(Temp);
  55   UnicodeStrToAsciiStr(Temp, resolved_name);
  56   return (resolved_name);
  57 }