StdLib/LibC/StdLib/realpath.c

   1 /** @file
   2   Implement the realpath function.
   3
   4   Copyright (c) 2011 - 2014, 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 #include <LibConfig.h>
  14 #include <Library/BaseLib.h>
  15 #include <Library/MemoryAllocationLib.h>
  16 #include <Library/PathLib.h>
  17 #include <errno.h>
  18
  19 /** The realpath() function shall derive, from the pathname pointed to by
  20     file_name, an absolute pathname that names the same file, whose resolution
  21     does not involve '.', '..', or symbolic links.
  22
  23     The generated pathname shall be stored as a null-terminated string, up to a
  24     maximum of {PATH_MAX} bytes, in the buffer pointed to by resolved_name.
  25
  26     If resolved_name is a null pointer, the behavior of realpath() is
  27     implementation-defined.
  28
  29   @param[in] file_name            The filename to convert.
  30   @param[in,out] resolved_name    The resultant name.
  31
  32   @retval NULL                    An error occured.
  33   @return resolved_name.
  34 **/
  35 char *
  36 realpath(
  37   char *file_name,
  38   char *resolved_name
  39   )
  40 {
  41   CHAR16 *Temp;
  42   if (file_name == NULL || resolved_name == NULL) {
  43     errno = EINVAL;
  44     return (NULL);
  45   }
  46   Temp = AllocateZeroPool((1+AsciiStrLen(file_name))*sizeof(CHAR16));
  47   if (Temp == NULL) {
  48     errno = ENOMEM;
  49     return (NULL);
  50   }
  51   AsciiStrToUnicodeStr(file_name, Temp);
  52   PathCleanUpDirectories(Temp);
  53   UnicodeStrToAsciiStr(Temp, resolved_name);
  54   return (resolved_name);
  55 }