/*============================================================================
  CMake - Cross Platform Makefile Generator
  Copyright 2000-2009 Kitware, Inc., Insight Software Consortium

  Distributed under the OSI-approved BSD License (the "License");
  see accompanying file Copyright.txt for details.

  This software is distributed WITHOUT ANY WARRANTY; without even the
  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the License for more information.
============================================================================*/
#if defined(_MSC_VER) && _MSC_VER < 1300
# define _WIN32_WINNT 0x0400 /* for wincrypt.h */
#endif
#include "cmSystemTools.h"
#include <ctype.h>
#include <errno.h>
#include <time.h>
#include <string.h>
#include <stdlib.h>
#ifdef __QNX__
# include <malloc.h> /* for malloc/free on QNX */
#endif
#include <cmsys/Glob.hxx>
#include <cmsys/RegularExpression.hxx>
#include <cmsys/Directory.hxx>
#include <cmsys/System.h>
#if defined(CMAKE_BUILD_WITH_CMAKE)
# include "cmArchiveWrite.h"
# include <cm_libarchive.h>
# include <cmsys/Terminal.h>
#endif
#include <cmsys/stl/algorithm>

#if defined(_WIN32)
# include <windows.h>
# include <wincrypt.h>
#else
# include <sys/time.h>
# include <sys/types.h>
# include <unistd.h>
# include <utime.h>
# include <sys/wait.h>
#endif

#include <sys/stat.h>

#if defined(_WIN32) && \
   (defined(_MSC_VER) || defined(__WATCOMC__) || \
    defined(__BORLANDC__) || defined(__MINGW32__))
# include <io.h>
#endif

#if defined(CMAKE_BUILD_WITH_CMAKE)
#  include <memory> // auto_ptr
#  include <fcntl.h>
#  include "cmCryptoHash.h"
#endif

#if defined(CMAKE_USE_ELF_PARSER)
# include "cmELF.h"
#endif

class cmSystemToolsFileTime
{
public:
#if defined(_WIN32) && !defined(__CYGWIN__)
  FILETIME timeCreation;
  FILETIME timeLastAccess;
  FILETIME timeLastWrite;
#else
  struct utimbuf timeBuf;
#endif
};

#if defined(__sgi) && !defined(__GNUC__)
# pragma set woff 1375 /* base class destructor not virtual */
#endif

#if !defined(HAVE_ENVIRON_NOT_REQUIRE_PROTOTYPE)
// For GetEnvironmentVariables
# if defined(_WIN32)
extern __declspec( dllimport ) char** environ;
# else
extern char** environ;
# endif
#endif

#ifdef _WIN32
class cmSystemToolsWindowsHandle
{
public:
  cmSystemToolsWindowsHandle(HANDLE h): handle_(h) {}
  ~cmSystemToolsWindowsHandle()
    {
    if(this->handle_ != INVALID_HANDLE_VALUE)
      {
      CloseHandle(this->handle_);
      }
    }
  operator bool() const { return this->handle_ != INVALID_HANDLE_VALUE; }
  bool operator !() const { return this->handle_ == INVALID_HANDLE_VALUE; }
  operator HANDLE() const { return this->handle_; }
private:
  HANDLE handle_;
};
#elif defined(__APPLE__)
#include <crt_externs.h>
#define environ (*_NSGetEnviron())
#endif

bool cmSystemTools::s_RunCommandHideConsole = false;
bool cmSystemTools::s_DisableRunCommandOutput = false;
bool cmSystemTools::s_ErrorOccured = false;
bool cmSystemTools::s_FatalErrorOccured = false;
bool cmSystemTools::s_DisableMessages = false;
bool cmSystemTools::s_ForceUnixPaths = false;

std::string cmSystemTools::s_Windows9xComspecSubstitute = "command.com";
void cmSystemTools::SetWindows9xComspecSubstitute(const char* str)
{
  if ( str )
    {
    cmSystemTools::s_Windows9xComspecSubstitute = str;
    }
}
const char* cmSystemTools::GetWindows9xComspecSubstitute()
{
  return cmSystemTools::s_Windows9xComspecSubstitute.c_str();
}

void (*cmSystemTools::s_ErrorCallback)(const char*, const char*,
                                       bool&, void*);
void (*cmSystemTools::s_StdoutCallback)(const char*, int len, void*);
void* cmSystemTools::s_ErrorCallbackClientData = 0;
void* cmSystemTools::s_StdoutCallbackClientData = 0;
bool (*cmSystemTools::s_InterruptCallback)(void*);
void* cmSystemTools::s_InterruptCallbackClientData = 0;

// replace replace with with as many times as it shows up in source.
// write the result into source.
#if defined(_WIN32) && !defined(__CYGWIN__)
void cmSystemTools::ExpandRegistryValues(std::string& source, KeyWOW64 view)
{
  // Regular expression to match anything inside [...] that begins in HKEY.
  // Note that there is a special rule for regular expressions to match a
  // close square-bracket inside a list delimited by square brackets.
  // The "[^]]" part of this expression will match any character except
  // a close square-bracket.  The ']' character must be the first in the
  // list of characters inside the [^...] block of the expression.
  cmsys::RegularExpression regEntry("\\[(HKEY[^]]*)\\]");

  // check for black line or comment
  while (regEntry.find(source))
    {
    // the arguments are the second match
    std::string key = regEntry.match(1);
    std::string val;
    if (ReadRegistryValue(key.c_str(), val, view))
      {
      std::string reg = "[";
      reg += key + "]";
      cmSystemTools::ReplaceString(source, reg.c_str(), val.c_str());
      }
    else
      {
      std::string reg = "[";
      reg += key + "]";
      cmSystemTools::ReplaceString(source, reg.c_str(), "/registry");
      }
    }
}
#else
void cmSystemTools::ExpandRegistryValues(std::string& source, KeyWOW64)
{
  cmsys::RegularExpression regEntry("\\[(HKEY[^]]*)\\]");
  while (regEntry.find(source))
    {
    // the arguments are the second match
    std::string key = regEntry.match(1);
    std::string val;
    std::string reg = "[";
    reg += key + "]";
    cmSystemTools::ReplaceString(source, reg.c_str(), "/registry");
    }

}
#endif

std::string cmSystemTools::EscapeQuotes(const char* str)
{
  std::string result = "";
  for(const char* ch = str; *ch != '\0'; ++ch)
    {
    if(*ch == '"')
      {
      result += '\\';
      }
    result += *ch;
    }
  return result;
}

std::string cmSystemTools::TrimWhitespace(const std::string& s)
{
  std::string::const_iterator start = s.begin();
  while(start != s.end() && *start == ' ')
    ++start;
  if (start == s.end())
    return "";

  std::string::const_iterator stop = s.end()-1;
  while(*stop == ' ')
    --stop;
  return std::string(start, stop+1);
}

void cmSystemTools::Error(const char* m1, const char* m2,
                          const char* m3, const char* m4)
{
  std::string message = "CMake Error: ";
  if(m1)
    {
    message += m1;
    }
  if(m2)
    {
    message += m2;
    }
  if(m3)
    {
    message += m3;
    }
  if(m4)
    {
    message += m4;
    }
  cmSystemTools::s_ErrorOccured = true;
  cmSystemTools::Message(message.c_str(),"Error");
}

void cmSystemTools::SetInterruptCallback(InterruptCallback f, void* clientData)
{
  s_InterruptCallback = f;
  s_InterruptCallbackClientData = clientData;
}

bool cmSystemTools::GetInterruptFlag()
{
  if(s_InterruptCallback)
    {
    return (*s_InterruptCallback)(s_InterruptCallbackClientData);
    }
  return false;
}

void cmSystemTools::SetErrorCallback(ErrorCallback f, void* clientData)
{
  s_ErrorCallback = f;
  s_ErrorCallbackClientData = clientData;
}

void cmSystemTools::SetStdoutCallback(StdoutCallback f, void* clientData)
{
  s_StdoutCallback = f;
  s_StdoutCallbackClientData = clientData;
}

void cmSystemTools::Stdout(const char* s)
{
  if(s_StdoutCallback)
    {
    (*s_StdoutCallback)(s, static_cast<int>(strlen(s)),
                        s_StdoutCallbackClientData);
    }
  else
    {
    std::cout << s;
    std::cout.flush();
    }
}

void cmSystemTools::Stderr(const char* s, int length)
{
    std::cerr.write(s, length);
    std::cerr.flush();
}

void cmSystemTools::Stdout(const char* s, int length)
{
  if(s_StdoutCallback)
    {
    (*s_StdoutCallback)(s, length, s_StdoutCallbackClientData);
    }
  else
    {
    std::cout.write(s, length);
    std::cout.flush();
    }
}

void cmSystemTools::Message(const char* m1, const char *title)
{
  if(s_DisableMessages)
    {
    return;
    }
  if(s_ErrorCallback)
    {
    (*s_ErrorCallback)(m1, title, s_DisableMessages,
                       s_ErrorCallbackClientData);
    return;
    }
  else
    {
    std::cerr << m1 << std::endl << std::flush;
    }

}


void cmSystemTools::ReportLastSystemError(const char* msg)
{
  std::string m = msg;
  m += ": System Error: ";
  m += Superclass::GetLastSystemError();
  cmSystemTools::Error(m.c_str());
}

bool cmSystemTools::IsInternallyOn(const char* val)
{
  if (!val)
    {
    return false;
    }
  std::basic_string<char> v = val;

  for(std::basic_string<char>::iterator c = v.begin();
      c != v.end(); c++)
    {
    *c = static_cast<char>(toupper(*c));
    }
  return (v == "I_ON" || v == "i_on");
}

bool cmSystemTools::IsOn(const char* val)
{
  if (!val)
    {
    return false;
    }
  std::basic_string<char> v = val;

  for(std::basic_string<char>::iterator c = v.begin();
      c != v.end(); c++)
    {
    *c = static_cast<char>(toupper(*c));
    }
  return (v == "ON" || v == "1" || v == "YES" || v == "TRUE" || v == "Y");
}

bool cmSystemTools::IsNOTFOUND(const char* val)
{
  size_t len = strlen(val);
  const char* notfound = "-NOTFOUND";
  const size_t lenNotFound = 9;
  if(len < lenNotFound-1)
    {
    return false;
    }
  if(len == lenNotFound-1)
    {
    return ( strcmp(val, "NOTFOUND") == 0);
    }
  return ((strncmp((val + (len - lenNotFound)), notfound, lenNotFound) == 0));
}


bool cmSystemTools::IsOff(const char* val)
{
  if (!val || strlen(val) == 0)
    {
    return true;
    }
  std::basic_string<char> v = val;

  for(std::basic_string<char>::iterator c = v.begin();
      c != v.end(); c++)
    {
    *c = static_cast<char>(toupper(*c));
    }
  return (v == "OFF" || v == "0" || v == "NO" || v == "FALSE" ||
          v == "N" || cmSystemTools::IsNOTFOUND(v.c_str()) || v == "IGNORE");
}

//----------------------------------------------------------------------------
void cmSystemTools::ParseWindowsCommandLine(const char* command,
                                            std::vector<std::string>& args)
{
  // See the MSDN document "Parsing C Command-Line Arguments" at
  // http://msdn2.microsoft.com/en-us/library/a1y7w461.aspx for rules
  // of parsing the windows command line.

  bool in_argument = false;
  bool in_quotes = false;
  int backslashes = 0;
  std::string arg;
  for(const char* c = command;*c; ++c)
    {
    if(*c == '\\')
      {
      ++backslashes;
      in_argument = true;
      }
    else if(*c == '"')
      {
      int backslash_pairs  = backslashes >> 1;
      int backslash_escaped = backslashes & 1;
      arg.append(backslash_pairs, '\\');
      backslashes = 0;
      if(backslash_escaped)
        {
        /* An odd number of backslashes precede this quote.
           It is escaped.  */
        arg.append(1, '"');
        }
      else
        {
        /* An even number of backslashes precede this quote.
           It is not escaped.  */
        in_quotes = !in_quotes;
        }
      in_argument = true;
      }
    else
      {
      arg.append(backslashes, '\\');
      backslashes = 0;
      if(isspace(*c))
        {
        if(in_quotes)
          {
          arg.append(1, *c);
          }
        else if(in_argument)
          {
          args.push_back(arg);
          arg = "";
          in_argument = false;
          }
        }
      else
        {
        in_argument = true;
        arg.append(1, *c);
        }
      }
    }
  arg.append(backslashes, '\\');
  if(in_argument)
    {
    args.push_back(arg);
    }
}

//----------------------------------------------------------------------------
class cmSystemToolsArgV
{
  char** ArgV;
public:
  cmSystemToolsArgV(char** argv): ArgV(argv) {}
  ~cmSystemToolsArgV()
    {
    for(char** arg = this->ArgV; arg && *arg; ++arg)
      {
      free(*arg);
      }
    free(this->ArgV);
    }
  void Store(std::vector<std::string>& args) const
    {
    for(char** arg = this->ArgV; arg && *arg; ++arg)
      {
      args.push_back(*arg);
      }
    }
  void Store(std::vector<cmStdString>& args) const
    {
    for(char** arg = this->ArgV; arg && *arg; ++arg)
      {
      args.push_back(*arg);
      }
    }
};

//----------------------------------------------------------------------------
void cmSystemTools::ParseUnixCommandLine(const char* command,
                                         std::vector<std::string>& args)
{
  // Invoke the underlying parser.
  cmSystemToolsArgV argv = cmsysSystem_Parse_CommandForUnix(command, 0);
  argv.Store(args);
}

//----------------------------------------------------------------------------
void cmSystemTools::ParseUnixCommandLine(const char* command,
                                         std::vector<cmStdString>& args)
{
  // Invoke the underlying parser.
  cmSystemToolsArgV argv = cmsysSystem_Parse_CommandForUnix(command, 0);
  argv.Store(args);
}

std::string cmSystemTools::EscapeWindowsShellArgument(const char* arg,
                                                      int shell_flags)
{
  char local_buffer[1024];
  char* buffer = local_buffer;
  int size = cmsysSystem_Shell_GetArgumentSizeForWindows(arg, shell_flags);
  if(size > 1024)
    {
    buffer = new char[size];
    }
  cmsysSystem_Shell_GetArgumentForWindows(arg, buffer, shell_flags);
  std::string result(buffer);
  if(buffer != local_buffer)
    {
    delete [] buffer;
    }
  return result;
}

std::vector<cmStdString> cmSystemTools::ParseArguments(const char* command)
{
  std::vector<cmStdString> args;
  std::string arg;

  bool win_path = false;

  if ((command[0] != '/' && command[1] == ':' && command[2] == '\\') ||
      (command[0] == '\"' && command[1] != '/' && command[2] == ':'
       && command[3] == '\\') ||
      (command[0] == '\'' && command[1] != '/' && command[2] == ':'
       && command[3] == '\\') ||
      (command[0] == '\\' && command[1] == '\\'))
    {
    win_path = true;
    }
  // Split the command into an argv array.
  for(const char* c = command; *c;)
    {
    // Skip over whitespace.
    while(*c == ' ' || *c == '\t')
      {
      ++c;
      }
    arg = "";
    if(*c == '"')
      {
      // Parse a quoted argument.
      ++c;
      while(*c && *c != '"')
        {
        arg.append(1, *c);
        ++c;
        }
      if(*c)
        {
        ++c;
        }
      args.push_back(arg);
      }
    else if(*c == '\'')
      {
      // Parse a quoted argument.
      ++c;
      while(*c && *c != '\'')
        {
        arg.append(1, *c);
        ++c;
        }
      if(*c)
        {
        ++c;
        }
      args.push_back(arg);
      }
    else if(*c)
      {
      // Parse an unquoted argument.
      while(*c && *c != ' ' && *c != '\t')
        {
        if(*c == '\\' && !win_path)
          {
          ++c;
          if(*c)
            {
            arg.append(1, *c);
            ++c;
            }
          }
        else
          {
          arg.append(1, *c);
          ++c;
          }
        }
      args.push_back(arg);
      }
    }

  return args;
}


bool cmSystemTools::RunSingleCommand(std::vector<cmStdString>const& command,
                                     std::string* output ,
                                     int* retVal , const char* dir ,
                                     OutputOption outputflag ,
                                     double timeout )
{
  std::vector<const char*> argv;
  for(std::vector<cmStdString>::const_iterator a = command.begin();
      a != command.end(); ++a)
    {
    argv.push_back(a->c_str());
    }
  argv.push_back(0);
  if ( output )
    {
    *output = "";
    }

  cmsysProcess* cp = cmsysProcess_New();
  cmsysProcess_SetCommand(cp, &*argv.begin());
  cmsysProcess_SetWorkingDirectory(cp, dir);
  if(cmSystemTools::GetRunCommandHideConsole())
    {
    cmsysProcess_SetOption(cp, cmsysProcess_Option_HideWindow, 1);
    }

  cmsysProcess_SetTimeout(cp, timeout);
  cmsysProcess_Execute(cp);

  std::vector<char> tempOutput;
  char* data;
  int length;
  int pipe;
  if ( output || outputflag != OUTPUT_NONE )
    {
    while((pipe = cmsysProcess_WaitForData(cp, &data, &length, 0)) > 0)
      {
      if(output || outputflag != OUTPUT_NONE)
        {
        // Translate NULL characters in the output into valid text.
        // Visual Studio 7 puts these characters in the output of its
        // build process.
        for(int i=0; i < length; ++i)
          {
          if(data[i] == '\0')
            {
            data[i] = ' ';
            }
          }
        }
      if ( output )
        {
        tempOutput.insert(tempOutput.end(), data, data+length);
        }
      if(outputflag != OUTPUT_NONE)
        {
        if(outputflag == OUTPUT_MERGE)
          {
          cmSystemTools::Stdout(data, length);
          }
        else
          {
          if(pipe == cmsysProcess_Pipe_STDERR)
            {
            cmSystemTools::Stderr(data, length);
            }
          else if(pipe == cmsysProcess_Pipe_STDOUT)
            {
            cmSystemTools::Stdout(data, length);
            }
          }
        }
      }
    }

  cmsysProcess_WaitForExit(cp, 0);
  if ( output && tempOutput.begin() != tempOutput.end())
    {
    output->append(&*tempOutput.begin(), tempOutput.size());
    }

  bool result = true;
  if(cmsysProcess_GetState(cp) == cmsysProcess_State_Exited)
    {
    if ( retVal )
      {
      *retVal = cmsysProcess_GetExitValue(cp);
      }
    else
      {
      if ( cmsysProcess_GetExitValue(cp) !=  0 )
        {
        result = false;
        }
      }
    }
  else if(cmsysProcess_GetState(cp) == cmsysProcess_State_Exception)
    {
    const char* exception_str = cmsysProcess_GetExceptionString(cp);
    if ( outputflag != OUTPUT_NONE )
      {
      std::cerr << exception_str << std::endl;
      }
    if ( output )
      {
      output->append(exception_str, strlen(exception_str));
      }
    result = false;
    }
  else if(cmsysProcess_GetState(cp) == cmsysProcess_State_Error)
    {
    const char* error_str = cmsysProcess_GetErrorString(cp);
    if ( outputflag != OUTPUT_NONE )
      {
      std::cerr << error_str << std::endl;
      }
    if ( output )
      {
      output->append(error_str, strlen(error_str));
      }
    result = false;
    }
  else if(cmsysProcess_GetState(cp) == cmsysProcess_State_Expired)
    {
    const char* error_str = "Process terminated due to timeout\n";
    if ( outputflag != OUTPUT_NONE )
      {
      std::cerr << error_str << std::endl;
      }
    if ( output )
      {
      output->append(error_str, strlen(error_str));
      }
    result = false;
    }

  cmsysProcess_Delete(cp);
  return result;
}

bool cmSystemTools::RunSingleCommand(
  const char* command,
  std::string* output,
  int *retVal,
  const char* dir,
  OutputOption outputflag,
  double timeout)
{
  if(s_DisableRunCommandOutput)
    {
    outputflag = OUTPUT_NONE;
    }

  std::vector<cmStdString> args = cmSystemTools::ParseArguments(command);

  if(args.size() < 1)
    {
    return false;
    }
  return cmSystemTools::RunSingleCommand(args, output,retVal,
                                         dir, outputflag, timeout);
}
bool cmSystemTools::RunCommand(const char* command,
                               std::string& output,
                               const char* dir,
                               bool verbose,
                               int timeout)
{
  int dummy;
  return cmSystemTools::RunCommand(command, output, dummy,
                                   dir, verbose, timeout);
}

#if defined(WIN32) && !defined(__CYGWIN__)
#include "cmWin32ProcessExecution.h"
// use this for shell commands like echo and dir
bool RunCommandViaWin32(const char* command,
                        const char* dir,
                        std::string& output,
                        int& retVal,
                        bool verbose,
                        int timeout)
{
#if defined(__BORLANDC__)
  return
    cmWin32ProcessExecution::
    BorlandRunCommand(command, dir, output,
                      retVal,
                      verbose, timeout,
                      cmSystemTools::GetRunCommandHideConsole());
#else // Visual studio
  ::SetLastError(ERROR_SUCCESS);
  if ( ! command )
    {
    cmSystemTools::Error("No command specified");
    return false;
    }
  cmWin32ProcessExecution resProc;
  if(cmSystemTools::GetRunCommandHideConsole())
    {
    resProc.SetHideWindows(true);
    }

  if ( cmSystemTools::GetWindows9xComspecSubstitute() )
    {
    resProc.SetConsoleSpawn(cmSystemTools::GetWindows9xComspecSubstitute() );
    }
  if ( !resProc.StartProcess(command, dir, verbose) )
    {
    output = resProc.GetOutput();
    if(verbose)
      {
      cmSystemTools::Stdout(output.c_str());
      }
    return false;
    }
  resProc.Wait(timeout);
  output = resProc.GetOutput();
  retVal = resProc.GetExitValue();
  return true;
#endif
}

// use this for shell commands like echo and dir
bool RunCommandViaSystem(const char* command,
                         const char* dir,
                         std::string& output,
                         int& retVal,
                         bool verbose)
{
  std::cout << "@@ " << command << std::endl;

  std::string commandInDir;
  if(dir)
    {
    commandInDir = "cd ";
    commandInDir += cmSystemTools::ConvertToOutputPath(dir);
    commandInDir += " && ";
    commandInDir += command;
    }
  else
    {
    commandInDir = command;
    }
  command = commandInDir.c_str();
  std::string commandToFile = command;
  commandToFile += " > ";
  std::string tempFile;
  tempFile += _tempnam(0, "cmake");

  commandToFile += tempFile;
  retVal = system(commandToFile.c_str());
  std::ifstream fin(tempFile.c_str());
  if(!fin)
    {
    if(verbose)
      {
      std::string errormsg = "RunCommand produced no output: command: \"";
      errormsg += command;
      errormsg += "\"";
      errormsg += "\nOutput file: ";
      errormsg += tempFile;
      cmSystemTools::Error(errormsg.c_str());
      }
    fin.close();
    cmSystemTools::RemoveFile(tempFile.c_str());
    return false;
    }
  bool multiLine = false;
  std::string line;
  while(cmSystemTools::GetLineFromStream(fin, line))
    {
    output += line;
    if(multiLine)
      {
      output += "\n";
      }
    multiLine = true;
    }
  fin.close();
  cmSystemTools::RemoveFile(tempFile.c_str());
  return true;
}

#else // We have popen

// BeOS seems to return from a successful pclose() before the process has
//  legitimately exited, or at least before SIGCHLD is thrown...the signal may
//  come quite some time after pclose returns! This causes havoc with later
//  parts of CMake that expect to catch the signal from other child processes,
//  so we explicitly wait to catch it here. This should be safe to do with
//  popen() so long as we don't actually collect the zombie process ourselves.
#ifdef __BEOS__
#include <signal.h>
#undef SIGBUS  // this is the same as SIGSEGV on BeOS and causes issues below.
static volatile bool beos_seen_signal = false;
static void beos_popen_workaround(int sig)
{
  beos_seen_signal = true;
}
#endif

bool RunCommandViaPopen(const char* command,
                        const char* dir,
                        std::string& output,
                        int& retVal,
                        bool verbose,
                        int /*timeout*/)
{
  // if only popen worked on windows.....
  std::string commandInDir;
  if(dir)
    {
    commandInDir = "cd \"";
    commandInDir += dir;
    commandInDir += "\" && ";
    commandInDir += command;
    }
  else
    {
    commandInDir = command;
    }
#ifndef __VMS
  commandInDir += " 2>&1";
#endif
  command = commandInDir.c_str();
  const int BUFFER_SIZE = 4096;
  char buffer[BUFFER_SIZE];
  if(verbose)
    {
    cmSystemTools::Stdout("running ");
    cmSystemTools::Stdout(command);
    cmSystemTools::Stdout("\n");
    }
  fflush(stdout);
  fflush(stderr);

#ifdef __BEOS__
  beos_seen_signal = false;
  signal(SIGCHLD, beos_popen_workaround);
#endif

  FILE* cpipe = popen(command, "r");
  if(!cpipe)
    {
#ifdef __BEOS__
    signal(SIGCHLD, SIG_DFL);
#endif
    return false;
    }
  if (!fgets(buffer, BUFFER_SIZE, cpipe))
    {
    buffer[0] = 0;
    }
  while(!feof(cpipe))
    {
    if(verbose)
      {
      cmSystemTools::Stdout(buffer);
      }
    output += buffer;
    if(!fgets(buffer, BUFFER_SIZE, cpipe))
      {
      buffer[0] = 0;
      }
    }

  retVal = pclose(cpipe);

#ifdef __BEOS__
  for (int i = 0; (!beos_seen_signal) && (i < 3); i++)
    {
    ::sleep(1);   // signals should interrupt this...
    }

  if (!beos_seen_signal)
    {
    signal(SIGCHLD, SIG_DFL);  // oh well, didn't happen. Go on anyhow.
    }
#endif

  if (WIFEXITED(retVal))
    {
    retVal = WEXITSTATUS(retVal);
    return true;
    }
  if (WIFSIGNALED(retVal))
    {
    retVal = WTERMSIG(retVal);
    cmOStringStream error;
    error << "\nProcess terminated due to ";
    switch (retVal)
      {
#ifdef SIGKILL
      case SIGKILL:
        error << "SIGKILL";
        break;
#endif
#ifdef SIGFPE
      case SIGFPE:
        error << "SIGFPE";
        break;
#endif
#ifndef __HAIKU__
#ifdef SIGBUS
      case SIGBUS:
        error << "SIGBUS";
        break;
#endif
#endif
#ifdef SIGSEGV
      case SIGSEGV:
        error << "SIGSEGV";
        break;
#endif
      default:
        error << "signal " << retVal;
        break;
      }
    output += error.str();
    }
  return false;
}

#endif  // endif WIN32 not CYGWIN


// run a command unix uses popen (easy)
// windows uses system and ShortPath
bool cmSystemTools::RunCommand(const char* command,
                               std::string& output,
                               int &retVal,
                               const char* dir,
                               bool verbose,
                               int timeout)
{
  if(s_DisableRunCommandOutput)
    {
    verbose = false;
    }

#if defined(WIN32) && !defined(__CYGWIN__)
  // if the command does not start with a quote, then
  // try to find the program, and if the program can not be
  // found use system to run the command as it must be a built in
  // shell command like echo or dir
  int count = 0;
  if(command[0] == '\"')
    {
    // count the number of quotes
    for(const char* s = command; *s != 0; ++s)
      {
      if(*s == '\"')
        {
        count++;
        if(count > 2)
          {
          break;
          }
        }
      }
    // if there are more than two double quotes use
    // GetShortPathName, the cmd.exe program in windows which
    // is used by system fails to execute if there are more than
    // one set of quotes in the arguments
    if(count > 2)
      {
      cmsys::RegularExpression quoted("^\"([^\"]*)\"[ \t](.*)");
      if(quoted.find(command))
        {
        std::string shortCmd;
        std::string cmd = quoted.match(1);
        std::string args = quoted.match(2);
        if(! cmSystemTools::FileExists(cmd.c_str()) )
          {
          shortCmd = cmd;
          }
        else if(!cmSystemTools::GetShortPath(cmd.c_str(), shortCmd))
          {
         cmSystemTools::Error("GetShortPath failed for " , cmd.c_str());
          return false;
          }
        shortCmd += " ";
        shortCmd += args;

        //return RunCommandViaSystem(shortCmd.c_str(), dir,
        //                           output, retVal, verbose);
        //return WindowsRunCommand(shortCmd.c_str(), dir,
        //output, retVal, verbose);
        return RunCommandViaWin32(shortCmd.c_str(), dir,
                                  output, retVal, verbose, timeout);
        }
      else
        {
        cmSystemTools::Error("Could not parse command line with quotes ",
                             command);
        }
      }
    }
  // if there is only one set of quotes or no quotes then just run the command
  //return RunCommandViaSystem(command, dir, output, retVal, verbose);
  //return WindowsRunCommand(command, dir, output, retVal, verbose);
  return ::RunCommandViaWin32(command, dir, output, retVal, verbose, timeout);
#else
  return ::RunCommandViaPopen(command, dir, output, retVal, verbose, timeout);
#endif
}

bool cmSystemTools::DoesFileExistWithExtensions(
  const char* name,
  const std::vector<std::string>& headerExts)
{
  std::string hname;

  for( std::vector<std::string>::const_iterator ext = headerExts.begin();
       ext != headerExts.end(); ++ext )
    {
    hname = name;
    hname += ".";
    hname += *ext;
    if(cmSystemTools::FileExists(hname.c_str()))
      {
      return true;
      }
    }
  return false;
}

std::string cmSystemTools::FileExistsInParentDirectories(const char* fname,
  const char* directory, const char* toplevel)
{
  std::string file = fname;
  cmSystemTools::ConvertToUnixSlashes(file);
  std::string dir = directory;
  cmSystemTools::ConvertToUnixSlashes(dir);
  std::string prevDir;
  while(dir != prevDir)
    {
    std::string path = dir + "/" + file;
    if ( cmSystemTools::FileExists(path.c_str()) )
      {
      return path;
      }
    if ( dir.size() < strlen(toplevel) )
      {
      break;
      }
    prevDir = dir;
    dir = cmSystemTools::GetParentDirectory(dir.c_str());
    }
  return "";
}

bool cmSystemTools::cmCopyFile(const char* source, const char* destination)
{
  return Superclass::CopyFileAlways(source, destination);
}

bool cmSystemTools::CopyFileIfDifferent(const char* source,
  const char* destination)
{
  return Superclass::CopyFileIfDifferent(source, destination);
}

//----------------------------------------------------------------------------
bool cmSystemTools::RenameFile(const char* oldname, const char* newname)
{
#ifdef _WIN32
  /* On Windows the move functions will not replace existing files.
     Check if the destination exists.  */
  struct stat newFile;
  if(stat(newname, &newFile) == 0)
    {
    /* The destination exists.  We have to replace it carefully.  The
       MoveFileEx function does what we need but is not available on
       Win9x.  */
    OSVERSIONINFO osv;
    DWORD attrs;

    /* Make sure the destination is not read only.  */
    attrs = GetFileAttributes(newname);
    if(attrs & FILE_ATTRIBUTE_READONLY)
      {
      SetFileAttributes(newname, attrs & ~FILE_ATTRIBUTE_READONLY);
      }

    /* Check the windows version number.  */
    osv.dwOSVersionInfoSize = sizeof(osv);
    GetVersionEx(&osv);
    if(osv.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
      {
      /* This is Win9x.  There is no MoveFileEx implementation.  We
         cannot quite rename the file atomically.  Just delete the
         destination and then move the file.  */
      DeleteFile(newname);
      return MoveFile(oldname, newname) != 0;
      }
    else
      {
      /* This is not Win9x.  Use the MoveFileEx implementation.  */
      return MoveFileEx(oldname, newname, MOVEFILE_REPLACE_EXISTING) != 0;
      }
    }
  else
    {
    /* The destination does not exist.  Just move the file.  */
    return MoveFile(oldname, newname) != 0;
    }
#else
  /* On UNIX we have an OS-provided call to do this atomically.  */
  return rename(oldname, newname) == 0;
#endif
}

bool cmSystemTools::ComputeFileMD5(const char* source, char* md5out)
{
#if defined(CMAKE_BUILD_WITH_CMAKE)
  cmCryptoHashMD5 md5;
  std::string str = md5.HashFile(source);
  strncpy(md5out, str.c_str(), 32);
  return !str.empty();
#else
  (void)source;
  (void)md5out;
  cmSystemTools::Message("md5sum not supported in bootstrapping mode","Error");
  return false;
#endif
}

std::string cmSystemTools::ComputeStringMD5(const char* input)
{
#if defined(CMAKE_BUILD_WITH_CMAKE)
  cmCryptoHashMD5 md5;
  return md5.HashString(input);
#else
  (void)input;
  cmSystemTools::Message("md5sum not supported in bootstrapping mode","Error");
  return "";
#endif
}

void cmSystemTools::Glob(const char *directory, const char *regexp,
                         std::vector<std::string>& files)
{
  cmsys::Directory d;
  cmsys::RegularExpression reg(regexp);

  if (d.Load(directory))
    {
    size_t numf;
        unsigned int i;
    numf = d.GetNumberOfFiles();
    for (i = 0; i < numf; i++)
      {
      std::string fname = d.GetFile(i);
      if (reg.find(fname))
        {
        files.push_back(fname);
        }
      }
    }
}


void cmSystemTools::GlobDirs(const char *fullPath,
                             std::vector<std::string>& files)
{
  std::string path = fullPath;
  std::string::size_type pos = path.find("/*");
  if(pos == std::string::npos)
    {
    files.push_back(fullPath);
    return;
    }
  std::string startPath = path.substr(0, pos);
  std::string finishPath = path.substr(pos+2);

  cmsys::Directory d;
  if (d.Load(startPath.c_str()))
    {
    for (unsigned int i = 0; i < d.GetNumberOfFiles(); ++i)
      {
      if((std::string(d.GetFile(i)) != ".")
         && (std::string(d.GetFile(i)) != ".."))
        {
        std::string fname = startPath;
        fname +="/";
        fname += d.GetFile(i);
        if(cmSystemTools::FileIsDirectory(fname.c_str()))
          {
          fname += finishPath;
          cmSystemTools::GlobDirs(fname.c_str(), files);
          }
        }
      }
    }
}


void cmSystemTools::ExpandList(std::vector<std::string> const& arguments,
                               std::vector<std::string>& newargs)
{
  std::vector<std::string>::const_iterator i;
  for(i = arguments.begin();i != arguments.end(); ++i)
    {
    cmSystemTools::ExpandListArgument(*i, newargs);
    }
}

void cmSystemTools::ExpandListArgument(const std::string& arg,
                                       std::vector<std::string>& newargs,
                                       bool emptyArgs)
{
  // If argument is empty, it is an empty list.
  if(arg.length() == 0 && !emptyArgs)
    {
    return;
    }
  // if there are no ; in the name then just copy the current string
  if(arg.find(';') == std::string::npos)
    {
    newargs.push_back(arg);
    return;
    }
  std::vector<char> newArgVec;
  // Break the string at non-escaped semicolons not nested in [].
  int squareNesting = 0;
  for(const char* c = arg.c_str(); *c; ++c)
    {
    switch(*c)
      {
      case '\\':
        {
        // We only want to allow escaping of semicolons.  Other
        // escapes should not be processed here.
        ++c;
        if(*c == ';')
          {
          newArgVec.push_back(*c);
          }
        else
          {
          newArgVec.push_back('\\');
          if(*c)
            {
            newArgVec.push_back(*c);
            }
          else
            {
            // Terminate the loop properly.
            --c;
            }
          }
        } break;
      case '[':
        {
        ++squareNesting;
        newArgVec.push_back(*c);
        } break;
      case ']':
        {
        --squareNesting;
        newArgVec.push_back(*c);
        } break;
      case ';':
        {
        // Break the string here if we are not nested inside square
        // brackets.
        if(squareNesting == 0)
          {
          if ( newArgVec.size() || emptyArgs )
            {
            // Add the last argument if the string is not empty.
            newArgVec.push_back(0);
            newargs.push_back(&*newArgVec.begin());
            newArgVec.clear();
            }
          }
        else
          {
          newArgVec.push_back(*c);
          }
        } break;
      default:
        {
        // Just append this character.
        newArgVec.push_back(*c);
        } break;
      }
    }
  if ( newArgVec.size() || emptyArgs )
    {
    // Add the last argument if the string is not empty.
    newArgVec.push_back(0);
    newargs.push_back(&*newArgVec.begin());
    }
}

bool cmSystemTools::SimpleGlob(const cmStdString& glob,
                               std::vector<cmStdString>& files,
                               int type /* = 0 */)
{
  files.clear();
  if ( glob[glob.size()-1] != '*' )
    {
    return false;
    }
  std::string path = cmSystemTools::GetFilenamePath(glob);
  std::string ppath = cmSystemTools::GetFilenameName(glob);
  ppath = ppath.substr(0, ppath.size()-1);
  if ( path.size() == 0 )
    {
    path = "/";
    }

  bool res = false;
  cmsys::Directory d;
  if (d.Load(path.c_str()))
    {
    for (unsigned int i = 0; i < d.GetNumberOfFiles(); ++i)
      {
      if((std::string(d.GetFile(i)) != ".")
         && (std::string(d.GetFile(i)) != ".."))
        {
        std::string fname = path;
        if ( path[path.size()-1] != '/' )
          {
          fname +="/";
          }
        fname += d.GetFile(i);
        std::string sfname = d.GetFile(i);
        if ( type > 0 && cmSystemTools::FileIsDirectory(fname.c_str()) )
          {
          continue;
          }
        if ( type < 0 && !cmSystemTools::FileIsDirectory(fname.c_str()) )
          {
          continue;
          }
        if ( sfname.size() >= ppath.size() &&
             sfname.substr(0, ppath.size()) ==
             ppath )
          {
          files.push_back(fname);
          res = true;
          }
        }
      }
    }
  return res;
}

cmSystemTools::FileFormat cmSystemTools::GetFileFormat(const char* cext)
{
  if ( ! cext || *cext == 0 )
    {
    return cmSystemTools::NO_FILE_FORMAT;
    }
  //std::string ext = cmSystemTools::LowerCase(cext);
  std::string ext = cext;
  if ( ext == "c" || ext == ".c" ||
       ext == "m" || ext == ".m"
    ) { return cmSystemTools::C_FILE_FORMAT; }
  if (
    ext == "C" || ext == ".C" ||
    ext == "M" || ext == ".M" ||
    ext == "c++" || ext == ".c++" ||
    ext == "cc" || ext == ".cc" ||
    ext == "cpp" || ext == ".cpp" ||
    ext == "cxx" || ext == ".cxx" ||
    ext == "mm" || ext == ".mm"
    ) { return cmSystemTools::CXX_FILE_FORMAT; }
  if (
    ext == "f" || ext == ".f" ||
    ext == "F" || ext == ".F" ||
    ext == "f77" || ext == ".f77" ||
    ext == "f90" || ext == ".f90" ||
    ext == "for" || ext == ".for" ||
    ext == "f95" || ext == ".f95"
    ) { return cmSystemTools::FORTRAN_FILE_FORMAT; }
  if ( ext == "java" || ext == ".java" )
    { return cmSystemTools::JAVA_FILE_FORMAT; }
  if (
    ext == "H" || ext == ".H" ||
    ext == "h" || ext == ".h" ||
    ext == "h++" || ext == ".h++" ||
    ext == "hm" || ext == ".hm" ||
    ext == "hpp" || ext == ".hpp" ||
    ext == "hxx" || ext == ".hxx" ||
    ext == "in" || ext == ".in" ||
    ext == "txx" || ext == ".txx"
    ) { return cmSystemTools::HEADER_FILE_FORMAT; }
  if ( ext == "rc" || ext == ".rc" )
    { return cmSystemTools::RESOURCE_FILE_FORMAT; }
  if ( ext == "def" || ext == ".def" )
    { return cmSystemTools::DEFINITION_FILE_FORMAT; }
  if ( ext == "lib" || ext == ".lib" ||
       ext == "a" || ext == ".a")
    { return cmSystemTools::STATIC_LIBRARY_FILE_FORMAT; }
  if ( ext == "o" || ext == ".o" ||
       ext == "obj" || ext == ".obj")
    { return cmSystemTools::OBJECT_FILE_FORMAT; }
#ifdef __APPLE__
  if ( ext == "dylib" || ext == ".dylib" )
    { return cmSystemTools::SHARED_LIBRARY_FILE_FORMAT; }
  if ( ext == "so" || ext == ".so" ||
       ext == "bundle" || ext == ".bundle" )
    { return cmSystemTools::MODULE_FILE_FORMAT; }
#else // __APPLE__
  if ( ext == "so" || ext == ".so" ||
       ext == "sl" || ext == ".sl" ||
       ext == "dll" || ext == ".dll" )
    { return cmSystemTools::SHARED_LIBRARY_FILE_FORMAT; }
#endif // __APPLE__
  return cmSystemTools::UNKNOWN_FILE_FORMAT;
}

bool cmSystemTools::Split(const char* s, std::vector<cmStdString>& l)
{
  std::vector<std::string> temp;
  bool res = Superclass::Split(s, temp);
  for(std::vector<std::string>::const_iterator i = temp.begin();
      i != temp.end(); ++i)
    {
    l.push_back(*i);
    }
  return res;
}

std::string cmSystemTools::ConvertToOutputPath(const char* path)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  if(s_ForceUnixPaths)
    {
    return cmSystemTools::ConvertToUnixOutputPath(path);
    }
  return cmSystemTools::ConvertToWindowsOutputPath(path);
#else
  return cmSystemTools::ConvertToUnixOutputPath(path);
#endif
}

void cmSystemTools::ConvertToOutputSlashes(std::string& path)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  if(!s_ForceUnixPaths)
    {
    // Convert to windows slashes.
    std::string::size_type pos = 0;
    while((pos = path.find('/', pos)) != std::string::npos)
      {
      path[pos++] = '\\';
      }
    }
#else
  static_cast<void>(path);
#endif
}

std::string cmSystemTools::ConvertToRunCommandPath(const char* path)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  return cmSystemTools::ConvertToWindowsOutputPath(path);
#else
  return cmSystemTools::ConvertToUnixOutputPath(path);
#endif
}

bool cmSystemTools::StringEndsWith(const char* str1, const char* str2)
{
  if ( !str1 || !str2 || strlen(str1) < strlen(str2) )
    {
    return 0;
    }
  return !strncmp(str1 + (strlen(str1)-strlen(str2)), str2, strlen(str2));
}

// compute the relative path from here to there
std::string cmSystemTools::RelativePath(const char* local, const char* remote)
{
  if(!cmSystemTools::FileIsFullPath(local))
    {
    cmSystemTools::Error("RelativePath must be passed a full path to local: ",
                         local);
    }
  if(!cmSystemTools::FileIsFullPath(remote))
    {
    cmSystemTools::Error
      ("RelativePath must be passed a full path to remote: ", remote);
    }
  return cmsys::SystemTools::RelativePath(local, remote);
}

#ifdef CMAKE_BUILD_WITH_CMAKE
//----------------------------------------------------------------------
bool cmSystemTools::UnsetEnv(const char* value)
{
#if !defined(HAVE_UNSETENV)
  std::string var = value;
  var += "=";
  return cmSystemTools::PutEnv(var.c_str());
#else
  unsetenv(value);
  return true;
#endif
}

//----------------------------------------------------------------------
std::vector<std::string> cmSystemTools::GetEnvironmentVariables()
{
  std::vector<std::string> env;
  int cc;
  for ( cc = 0; environ[cc]; ++ cc )
    {
    env.push_back(environ[cc]);
    }
  return env;
}

//----------------------------------------------------------------------
std::vector<std::string> cmSystemTools::AppendEnv(
  std::vector<std::string>* env)
{
  std::vector<std::string> origEnv = GetEnvironmentVariables();

  if (env && env->size()>0)
    {
    std::vector<std::string>::const_iterator eit;

    for (eit = env->begin(); eit!= env->end(); ++eit)
      {
      PutEnv(eit->c_str());
      }
    }

  return origEnv;
}

//----------------------------------------------------------------------
void cmSystemTools::RestoreEnv(const std::vector<std::string>& env)
{
  std::vector<std::string>::const_iterator eit;

  // First clear everything in the current environment:
  //
  std::vector<std::string> currentEnv = GetEnvironmentVariables();
  for (eit = currentEnv.begin(); eit!= currentEnv.end(); ++eit)
    {
    std::string var(*eit);

    std::string::size_type pos = var.find("=");
    if (pos != std::string::npos)
      {
      var = var.substr(0, pos);
      }

    UnsetEnv(var.c_str());
    }

  // Then put back each entry from the original environment:
  //
  for (eit = env.begin(); eit!= env.end(); ++eit)
    {
    PutEnv(eit->c_str());
    }
}

//----------------------------------------------------------------------
cmSystemTools::SaveRestoreEnvironment::SaveRestoreEnvironment()
{
  this->Env = cmSystemTools::GetEnvironmentVariables();
}

//----------------------------------------------------------------------
cmSystemTools::SaveRestoreEnvironment::~SaveRestoreEnvironment()
{
  cmSystemTools::RestoreEnv(this->Env);
}
#endif

void cmSystemTools::EnableVSConsoleOutput()
{
  // Visual Studio 8 2005 (devenv.exe or VCExpress.exe) will not
  // display output to the console unless this environment variable is
  // set.  We need it to capture the output of these build tools.
  // Note for future work that one could pass "/out \\.\pipe\NAME" to
  // either of these executables where NAME is created with
  // CreateNamedPipe.  This would bypass the internal buffering of the
  // output and allow it to be captured on the fly.
#ifdef _WIN32
  cmSystemTools::PutEnv("vsconsoleoutput=1");
#endif
}

bool cmSystemTools::IsPathToFramework(const char* path)
{
  if(cmSystemTools::FileIsFullPath(path))
    {
    std::string libname = path;
    if(libname.find(".framework") == libname.size()+1-sizeof(".framework"))
      {
      return true;
      }
    }
  return false;
}

bool cmSystemTools::CreateTar(const char* outFileName,
                              const std::vector<cmStdString>& files,
                              bool gzip, bool bzip2, bool verbose)
{
#if defined(CMAKE_BUILD_WITH_CMAKE)
  std::string cwd = cmSystemTools::GetCurrentWorkingDirectory();
  std::ofstream fout(outFileName, std::ios::out | cmsys_ios_binary);
  if(!fout)
    {
    std::string e = "Cannot open output file \"";
    e += outFileName;
    e += "\": ";
    e += cmSystemTools::GetLastSystemError();
    cmSystemTools::Error(e.c_str());
    return false;
    }
  cmArchiveWrite a(fout, (gzip? cmArchiveWrite::CompressGZip :
                          (bzip2? cmArchiveWrite::CompressBZip2 :
                           cmArchiveWrite::CompressNone)),
                           cmArchiveWrite::TypeTAR);
  a.SetVerbose(verbose);
  for(std::vector<cmStdString>::const_iterator i = files.begin();
      i != files.end(); ++i)
    {
    std::string path = *i;
    if(cmSystemTools::FileIsFullPath(path.c_str()))
      {
      // Get the relative path to the file.
      path = cmSystemTools::RelativePath(cwd.c_str(), path.c_str());
      }
    if(!a.Add(path))
      {
      break;
      }
    }
  if(!a)
    {
    cmSystemTools::Error(a.GetError().c_str());
    return false;
    }
  return true;
#else
  (void)outFileName;
  (void)files;
  (void)gzip;
  (void)verbose;
  return false;
#endif
}

#if defined(CMAKE_BUILD_WITH_CMAKE)
namespace{
#define BSDTAR_FILESIZE_PRINTF  "%lu"
#define BSDTAR_FILESIZE_TYPE    unsigned long
  void
    list_item_verbose(FILE *out, struct archive_entry *entry)
{
  char                   tmp[100];
  size_t                         w;
  const char            *p;
  const char            *fmt;
  time_t                         tim;
  static time_t          now;
  size_t u_width = 6;
  size_t gs_width = 13;

  /*
   * We avoid collecting the entire list in memory at once by
   * listing things as we see them.  However, that also means we can't
   * just pre-compute the field widths.  Instead, we start with guesses
   * and just widen them as necessary.  These numbers are completely
   * arbitrary.
   */
  if (!now)
    {
    time(&now);
    }
  fprintf(out, "%s %d ",
          archive_entry_strmode(entry),
          archive_entry_nlink(entry));

  /* Use uname if it's present, else uid. */
  p = archive_entry_uname(entry);
  if ((p == NULL) || (*p == '\0'))
    {
    sprintf(tmp, "%lu ",
            (unsigned long)archive_entry_uid(entry));
    p = tmp;
    }
  w = strlen(p);
  if (w > u_width)
    {
    u_width = w;
    }
  fprintf(out, "%-*s ", (int)u_width, p);
  /* Use gname if it's present, else gid. */
  p = archive_entry_gname(entry);
  if (p != NULL && p[0] != '\0')
    {
    fprintf(out, "%s", p);
    w = strlen(p);
    }
  else
    {
    sprintf(tmp, "%lu",
            (unsigned long)archive_entry_gid(entry));
    w = strlen(tmp);
    fprintf(out, "%s", tmp);
    }

  /*
   * Print device number or file size, right-aligned so as to make
   * total width of group and devnum/filesize fields be gs_width.
   * If gs_width is too small, grow it.
   */
  if (archive_entry_filetype(entry) == AE_IFCHR
      || archive_entry_filetype(entry) == AE_IFBLK)
    {
    sprintf(tmp, "%lu,%lu",
            (unsigned long)archive_entry_rdevmajor(entry),
            (unsigned long)archive_entry_rdevminor(entry));
    }
  else
    {
    /*
     * Note the use of platform-dependent macros to format
     * the filesize here.  We need the format string and the
     * corresponding type for the cast.
     */
    sprintf(tmp, BSDTAR_FILESIZE_PRINTF,
            (BSDTAR_FILESIZE_TYPE)archive_entry_size(entry));
    }
  if (w + strlen(tmp) >= gs_width)
    {
    gs_width = w+strlen(tmp)+1;
    }
  fprintf(out, "%*s", (int)(gs_width - w), tmp);

  /* Format the time using 'ls -l' conventions. */
  tim = archive_entry_mtime(entry);
#define HALF_YEAR (time_t)365 * 86400 / 2
#if defined(_WIN32) && !defined(__CYGWIN__)
  /* Windows' strftime function does not support %e format. */
#define DAY_FMT  "%d"
#else
#define DAY_FMT  "%e"  /* Day number without leading zeros */
#endif
  if (tim < now - HALF_YEAR || tim > now + HALF_YEAR)
    {
    fmt = DAY_FMT " %b  %Y";
    }
  else
    {
    fmt = DAY_FMT " %b %H:%M";
    }
  strftime(tmp, sizeof(tmp), fmt, localtime(&tim));
  fprintf(out, " %s ", tmp);
  fprintf(out, "%s", archive_entry_pathname(entry));

  /* Extra information for links. */
  if (archive_entry_hardlink(entry)) /* Hard link */
    {
    fprintf(out, " link to %s",
            archive_entry_hardlink(entry));
    }
  else if (archive_entry_symlink(entry)) /* Symbolic link */
    {
    fprintf(out, " -> %s", archive_entry_symlink(entry));
    }
}
#ifdef __BORLANDC__
# pragma warn -8066 /* unreachable code */
#endif

long copy_data(struct archive *ar, struct archive *aw)
{
  long r;
  const void *buff;
  size_t size;
#if defined(ARCHIVE_VERSION_NUMBER) && ARCHIVE_VERSION_NUMBER >= 3000000
  __LA_INT64_T offset;
#else
  off_t offset;
#endif

  for (;;)
    {
    r = archive_read_data_block(ar, &buff, &size, &offset);
    if (r == ARCHIVE_EOF)
      {
      return (ARCHIVE_OK);
      }
    if (r != ARCHIVE_OK)
      {
      return (r);
      }
    r = archive_write_data_block(aw, buff, size, offset);
    if (r != ARCHIVE_OK)
      {
      cmSystemTools::Message("archive_write_data_block()",
                             archive_error_string(aw));
      return (r);
      }
    }
  return r;
}

bool extract_tar(const char* outFileName, bool verbose,
                 bool extract)
{
  struct archive* a = archive_read_new();
  struct archive *ext = archive_write_disk_new();
  archive_read_support_compression_all(a);
  archive_read_support_format_all(a);
  struct archive_entry *entry;
  int r = archive_read_open_file(a, outFileName, 10240);
  if(r)
    {
    cmSystemTools::Error("Problem with archive_read_open_file(): ",
                         archive_error_string(a));
    return false;
    }
  for (;;)
    {
    r = archive_read_next_header(a, &entry);
    if (r == ARCHIVE_EOF)
      {
      break;
      }
    if (r != ARCHIVE_OK)
      {
      cmSystemTools::Error("Problem with archive_read_next_header(): ",
                           archive_error_string(a));
      }
    if (verbose && extract)
      {
      cmSystemTools::Stdout("x ");
      cmSystemTools::Stdout(archive_entry_pathname(entry));
      }
    if(verbose && !extract)
      {
      list_item_verbose(stdout, entry);
      }
    else if(!extract)
      {
      cmSystemTools::Stdout(archive_entry_pathname(entry));
      }
    if(extract)
      {
      r = archive_write_disk_set_options(ext, ARCHIVE_EXTRACT_TIME);
      if (r != ARCHIVE_OK)
        {
        cmSystemTools::Error(
          "Problem with archive_write_disk_set_options(): ",
          archive_error_string(ext));
        }

      r = archive_write_header(ext, entry);
      if (r != ARCHIVE_OK)
        {
        cmSystemTools::Error("Problem with archive_write_header(): ",
                             archive_error_string(ext));
        cmSystemTools::Error("Current file:",
                             archive_entry_pathname(entry));
        }
      else
        {
        copy_data(a, ext);
        r = archive_write_finish_entry(ext);
        if (r != ARCHIVE_OK)
          {
          cmSystemTools::Error("Problem with archive_write_finish_entry(): ",
                               archive_error_string(ext));
          }
        }
      }
    if (verbose || !extract)
      {
      cmSystemTools::Stdout("\n");
      }
    }
  archive_read_close(a);
  archive_read_finish(a);
  return true;

}
}
#endif

bool cmSystemTools::ExtractTar(const char* outFileName,
                               bool , bool verbose)
{
#if defined(CMAKE_BUILD_WITH_CMAKE)
  return extract_tar(outFileName, verbose, true);
#else
  (void)outFileName;
  (void)verbose;
  return false;
#endif
}

bool cmSystemTools::ListTar(const char* outFileName,
                            bool ,
                            bool verbose)
{
#if defined(CMAKE_BUILD_WITH_CMAKE)
  return extract_tar(outFileName, verbose, false);
#else
  (void)outFileName;
  (void)verbose;
  return false;
#endif
}

int cmSystemTools::WaitForLine(cmsysProcess* process, std::string& line,
                               double timeout,
                               std::vector<char>& out,
                               std::vector<char>& err)
{
  line = "";
  std::vector<char>::iterator outiter = out.begin();
  std::vector<char>::iterator erriter = err.begin();
  while(1)
    {
    // Check for a newline in stdout.
    for(;outiter != out.end(); ++outiter)
      {
      if((*outiter == '\r') && ((outiter+1) == out.end()))
        {
        break;
        }
      else if(*outiter == '\n' || *outiter == '\0')
        {
        std::vector<char>::size_type length = outiter-out.begin();
        if(length > 1 && *(outiter-1) == '\r')
          {
          --length;
          }
        if(length > 0)
          {
          line.append(&out[0], length);
          }
        out.erase(out.begin(), outiter+1);
        return cmsysProcess_Pipe_STDOUT;
        }
      }

    // Check for a newline in stderr.
    for(;erriter != err.end(); ++erriter)
      {
      if((*erriter == '\r') && ((erriter+1) == err.end()))
        {
        break;
        }
      else if(*erriter == '\n' || *erriter == '\0')
        {
        std::vector<char>::size_type length = erriter-err.begin();
        if(length > 1 && *(erriter-1) == '\r')
          {
          --length;
          }
        if(length > 0)
          {
          line.append(&err[0], length);
          }
        err.erase(err.begin(), erriter+1);
        return cmsysProcess_Pipe_STDERR;
        }
      }

    // No newlines found.  Wait for more data from the process.
    int length;
    char* data;
    int pipe = cmsysProcess_WaitForData(process, &data, &length, &timeout);
    if(pipe == cmsysProcess_Pipe_Timeout)
      {
      // Timeout has been exceeded.
      return pipe;
      }
    else if(pipe == cmsysProcess_Pipe_STDOUT)
      {
      // Append to the stdout buffer.
      std::vector<char>::size_type size = out.size();
      out.insert(out.end(), data, data+length);
      outiter = out.begin()+size;
      }
    else if(pipe == cmsysProcess_Pipe_STDERR)
      {
      // Append to the stderr buffer.
      std::vector<char>::size_type size = err.size();
      err.insert(err.end(), data, data+length);
      erriter = err.begin()+size;
      }
    else if(pipe == cmsysProcess_Pipe_None)
      {
      // Both stdout and stderr pipes have broken.  Return leftover data.
      if(!out.empty())
        {
        line.append(&out[0], outiter-out.begin());
        out.erase(out.begin(), out.end());
        return cmsysProcess_Pipe_STDOUT;
        }
      else if(!err.empty())
        {
        line.append(&err[0], erriter-err.begin());
        err.erase(err.begin(), err.end());
        return cmsysProcess_Pipe_STDERR;
        }
      else
        {
        return cmsysProcess_Pipe_None;
        }
      }
    }
}

void cmSystemTools::DoNotInheritStdPipes()
{
#ifdef _WIN32
  // Check to see if we are attached to a console
  // if so, then do not stop the inherited pipes
  // or stdout and stderr will not show up in dos
  // shell windows
  CONSOLE_SCREEN_BUFFER_INFO hOutInfo;
  HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
  if(GetConsoleScreenBufferInfo(hOut, &hOutInfo))
    {
    return;
    }
  {
  HANDLE out = GetStdHandle(STD_OUTPUT_HANDLE);
  DuplicateHandle(GetCurrentProcess(), out,
                  GetCurrentProcess(), &out, 0, FALSE,
                  DUPLICATE_SAME_ACCESS | DUPLICATE_CLOSE_SOURCE);
  SetStdHandle(STD_OUTPUT_HANDLE, out);
  }
  {
  HANDLE out = GetStdHandle(STD_ERROR_HANDLE);
  DuplicateHandle(GetCurrentProcess(), out,
                  GetCurrentProcess(), &out, 0, FALSE,
                  DUPLICATE_SAME_ACCESS | DUPLICATE_CLOSE_SOURCE);
  SetStdHandle(STD_ERROR_HANDLE, out);
  }
#endif
}

//----------------------------------------------------------------------------
bool cmSystemTools::CopyFileTime(const char* fromFile, const char* toFile)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  cmSystemToolsWindowsHandle hFrom =
    CreateFile(fromFile, GENERIC_READ, FILE_SHARE_READ, 0,
               OPEN_EXISTING, 0, 0);
  cmSystemToolsWindowsHandle hTo =
    CreateFile(toFile, GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
  if(!hFrom || !hTo)
    {
    return false;
    }
  FILETIME timeCreation;
  FILETIME timeLastAccess;
  FILETIME timeLastWrite;
  if(!GetFileTime(hFrom, &timeCreation, &timeLastAccess, &timeLastWrite))
    {
    return false;
    }
  if(!SetFileTime(hTo, &timeCreation, &timeLastAccess, &timeLastWrite))
    {
    return false;
    }
#else
  struct stat fromStat;
  if(stat(fromFile, &fromStat) < 0)
    {
    return false;
    }

  struct utimbuf buf;
  buf.actime = fromStat.st_atime;
  buf.modtime = fromStat.st_mtime;
  if(utime(toFile, &buf) < 0)
    {
    return false;
    }
#endif
  return true;
}

//----------------------------------------------------------------------------
cmSystemToolsFileTime* cmSystemTools::FileTimeNew()
{
  return new cmSystemToolsFileTime;
}

//----------------------------------------------------------------------------
void cmSystemTools::FileTimeDelete(cmSystemToolsFileTime* t)
{
  delete t;
}

//----------------------------------------------------------------------------
bool cmSystemTools::FileTimeGet(const char* fname, cmSystemToolsFileTime* t)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  cmSystemToolsWindowsHandle h =
    CreateFile(fname, GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, 0, 0);
  if(!h)
    {
    return false;
    }
  if(!GetFileTime(h, &t->timeCreation, &t->timeLastAccess, &t->timeLastWrite))
    {
    return false;
    }
#else
  struct stat st;
  if(stat(fname, &st) < 0)
    {
    return false;
    }
  t->timeBuf.actime = st.st_atime;
  t->timeBuf.modtime = st.st_mtime;
#endif
  return true;
}

//----------------------------------------------------------------------------
bool cmSystemTools::FileTimeSet(const char* fname, cmSystemToolsFileTime* t)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  cmSystemToolsWindowsHandle h =
    CreateFile(fname, GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
  if(!h)
    {
    return false;
    }
  if(!SetFileTime(h, &t->timeCreation, &t->timeLastAccess, &t->timeLastWrite))
    {
    return false;
    }
#else
  if(utime(fname, &t->timeBuf) < 0)
    {
    return false;
    }
#endif
  return true;
}

//----------------------------------------------------------------------------
#ifdef _WIN32
# ifndef CRYPT_SILENT
#  define CRYPT_SILENT 0x40 /* Not defined by VS 6 version of header.  */
# endif
static int WinCryptRandom(void* data, size_t size)
{
  int result = 0;
  HCRYPTPROV hProvider = 0;
  if(CryptAcquireContextW(&hProvider, 0, 0, PROV_RSA_FULL,
                          CRYPT_VERIFYCONTEXT | CRYPT_SILENT))
    {
    result = CryptGenRandom(hProvider, (DWORD)size, (BYTE*)data)? 1:0;
    CryptReleaseContext(hProvider, 0);
    }
  return result;
}
#endif

//----------------------------------------------------------------------------
unsigned int cmSystemTools::RandomSeed()
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  unsigned int seed = 0;

  // Try using a real random source.
  if(WinCryptRandom(&seed, sizeof(seed)))
    {
    return seed;
    }

  // Fall back to the time and pid.
  FILETIME ft;
  GetSystemTimeAsFileTime(&ft);
  unsigned int t1 = static_cast<unsigned int>(ft.dwHighDateTime);
  unsigned int t2 = static_cast<unsigned int>(ft.dwLowDateTime);
  unsigned int pid = static_cast<unsigned int>(GetCurrentProcessId());
  return t1 ^ t2 ^ pid;
#else
  union
  {
    unsigned int integer;
    char bytes[sizeof(unsigned int)];
  } seed;

  // Try using a real random source.
  std::ifstream fin("/dev/urandom");
  if(fin && fin.read(seed.bytes, sizeof(seed)) &&
     fin.gcount() == sizeof(seed))
    {
    return seed.integer;
    }

  // Fall back to the time and pid.
  struct timeval t;
  gettimeofday(&t, 0);
  unsigned int pid = static_cast<unsigned int>(getpid());
  unsigned int tv_sec = static_cast<unsigned int>(t.tv_sec);
  unsigned int tv_usec = static_cast<unsigned int>(t.tv_usec);
  // Since tv_usec never fills more than 11 bits we shift it to fill
  // in the slow-changing high-order bits of tv_sec.
  return tv_sec ^ (tv_usec << 21) ^ pid;
#endif
}

//----------------------------------------------------------------------------
static std::string cmSystemToolsExecutableDirectory;
void cmSystemTools::FindExecutableDirectory(const char* argv0)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  (void)argv0; // ignore this on windows
  char modulepath[_MAX_PATH];
  ::GetModuleFileName(NULL, modulepath, sizeof(modulepath));
  cmSystemToolsExecutableDirectory =
    cmSystemTools::GetFilenamePath(modulepath);
  return;
#else
  std::string errorMsg;
  std::string exe;
  if(cmSystemTools::FindProgramPath(argv0, exe, errorMsg))
    {
    // remove symlinks
    exe = cmSystemTools::GetRealPath(exe.c_str());
    cmSystemToolsExecutableDirectory =
      cmSystemTools::GetFilenamePath(exe.c_str());
    }
  else
    {
    // ???
    }
#endif
}

//----------------------------------------------------------------------------
const char* cmSystemTools::GetExecutableDirectory()
{
  return cmSystemToolsExecutableDirectory.c_str();
}

//----------------------------------------------------------------------------
#if defined(CMAKE_BUILD_WITH_CMAKE)
void cmSystemTools::MakefileColorEcho(int color, const char* message,
                                      bool newline, bool enabled)
{
  // On some platforms (an MSYS prompt) cmsysTerminal may not be able
  // to determine whether the stream is displayed on a tty.  In this
  // case it assumes no unless we tell it otherwise.  Since we want
  // color messages to be displayed for users we will assume yes.
  // However, we can test for some situations when the answer is most
  // likely no.
  int assumeTTY = cmsysTerminal_Color_AssumeTTY;
  if(cmSystemTools::GetEnv("DART_TEST_FROM_DART") ||
     cmSystemTools::GetEnv("DASHBOARD_TEST_FROM_CTEST") ||
     cmSystemTools::GetEnv("CTEST_INTERACTIVE_DEBUG_MODE"))
    {
    // Avoid printing color escapes during dashboard builds.
    assumeTTY = 0;
    }

  if(enabled)
    {
    cmsysTerminal_cfprintf(color | assumeTTY, stdout, "%s%s",
                           message, newline? "\n" : "");
    }
  else
    {
    // Color is disabled.  Print without color.
    fprintf(stdout, "%s%s", message, newline? "\n" : "");
    }
}
#endif

//----------------------------------------------------------------------------
bool cmSystemTools::GuessLibrarySOName(std::string const& fullPath,
                                       std::string& soname)
{
  // For ELF shared libraries use a real parser to get the correct
  // soname.
#if defined(CMAKE_USE_ELF_PARSER)
  cmELF elf(fullPath.c_str());
  if(elf)
    {
    return elf.GetSOName(soname);
    }
#endif

  // If the file is not a symlink we have no guess for its soname.
  if(!cmSystemTools::FileIsSymlink(fullPath.c_str()))
    {
    return false;
    }
  if(!cmSystemTools::ReadSymlink(fullPath.c_str(), soname))
    {
    return false;
    }

  // If the symlink has a path component we have no guess for the soname.
  if(!cmSystemTools::GetFilenamePath(soname).empty())
    {
    return false;
    }

  // If the symlink points at an extended version of the same name
  // assume it is the soname.
  std::string name = cmSystemTools::GetFilenameName(fullPath);
  if(soname.length() > name.length() &&
     soname.substr(0, name.length()) == name)
    {
    return true;
    }
  return false;
}

//----------------------------------------------------------------------------
#if defined(CMAKE_USE_ELF_PARSER)
std::string::size_type cmSystemToolsFindRPath(std::string const& have,
                                              std::string const& want)
{
  // Search for the desired rpath.
  std::string::size_type pos = have.find(want);

  // If the path is not present we are done.
  if(pos == std::string::npos)
    {
    return pos;
    }

  // Build a regex to match a properly separated path instance.
  std::string regex_str = "(^|:)(";
  for(std::string::const_iterator i = want.begin(); i != want.end(); ++i)
    {
    int ch = *i;
    if(!(('a' <= ch && ch <= 'z') ||
         ('A' <= ch && ch <= 'Z') ||
         ('0' <= ch && ch <= '9')))
      {
      // Escape the non-alphanumeric character.
      regex_str += "\\";
      }
    // Store the character.
    regex_str.append(1, static_cast<char>(ch));
    }
  regex_str += ")(:|$)";

  // Look for the separated path.
  cmsys::RegularExpression regex(regex_str.c_str());
  if(regex.find(have))
    {
    // Return the position of the path portion.
    return regex.start(2);
    }
  else
    {
    // The desired rpath was not found.
    return std::string::npos;
    }
}
#endif

#if defined(CMAKE_USE_ELF_PARSER)
struct cmSystemToolsRPathInfo
{
  unsigned long Position;
  unsigned long Size;
  std::string Name;
  std::string Value;
};
#endif

//----------------------------------------------------------------------------
bool cmSystemTools::ChangeRPath(std::string const& file,
                                std::string const& oldRPath,
                                std::string const& newRPath,
                                std::string* emsg,
                                bool* changed)
{
#if defined(CMAKE_USE_ELF_PARSER)
  if(changed)
    {
    *changed = false;
    }
  int rp_count = 0;
  cmSystemToolsRPathInfo rp[2];
  {
  // Parse the ELF binary.
  cmELF elf(file.c_str());

  // Get the RPATH and RUNPATH entries from it.
  int se_count = 0;
  cmELF::StringEntry const* se[2] = {0, 0};
  const char* se_name[2] = {0, 0};
  if(cmELF::StringEntry const* se_rpath = elf.GetRPath())
    {
    se[se_count] = se_rpath;
    se_name[se_count] = "RPATH";
    ++se_count;
    }
  if(cmELF::StringEntry const* se_runpath = elf.GetRunPath())
    {
    se[se_count] = se_runpath;
    se_name[se_count] = "RUNPATH";
    ++se_count;
    }
  if(se_count == 0)
    {
    if(newRPath.empty())
      {
      // The new rpath is empty and there is no rpath anyway so it is
      // okay.
      return true;
      }
    else
      {
      if(emsg)
        {
        *emsg = "No valid ELF RPATH or RUNPATH entry exists in the file; ";
        *emsg += elf.GetErrorMessage();
        }
      return false;
      }
    }

  for(int i=0; i < se_count; ++i)
    {
    // If both RPATH and RUNPATH refer to the same string literal it
    // needs to be changed only once.
    if(rp_count && rp[0].Position == se[i]->Position)
      {
      continue;
      }

    // Make sure the current rpath contains the old rpath.
    std::string::size_type pos =
      cmSystemToolsFindRPath(se[i]->Value, oldRPath);
    if(pos == std::string::npos)
      {
      // If it contains the new rpath instead then it is okay.
      if(cmSystemToolsFindRPath(se[i]->Value, newRPath) != std::string::npos)
        {
        continue;
        }
      if(emsg)
        {
        cmOStringStream e;
        e << "The current " << se_name[i] << " is:\n"
          << "  " << se[i]->Value << "\n"
          << "which does not contain:\n"
          << "  " << oldRPath << "\n"
          << "as was expected.";
        *emsg = e.str();
        }
      return false;
      }

    // Store information about the entry in the file.
    rp[rp_count].Position = se[i]->Position;
    rp[rp_count].Size = se[i]->Size;
    rp[rp_count].Name = se_name[i];

    // Construct the new value which preserves the part of the path
    // not being changed.
    rp[rp_count].Value = se[i]->Value.substr(0, pos);
    rp[rp_count].Value += newRPath;
    rp[rp_count].Value += se[i]->Value.substr(pos+oldRPath.length(),
                                              oldRPath.npos);

    // Make sure there is enough room to store the new rpath and at
    // least one null terminator.
    if(rp[rp_count].Size < rp[rp_count].Value.length()+1)
      {
      if(emsg)
        {
        *emsg = "The replacement path is too long for the ";
        *emsg += se_name[i];
        *emsg += " entry.";
        }
      return false;
      }

    // This entry is ready for update.
    ++rp_count;
    }
  }

  // If no runtime path needs to be changed, we are done.
  if(rp_count == 0)
    {
    return true;
    }

  {
  // Open the file for update.
  std::ofstream f(file.c_str(),
                  std::ios::in | std::ios::out | std::ios::binary);
  if(!f)
    {
    if(emsg)
      {
      *emsg = "Error opening file for update.";
      }
    return false;
    }

  // Store the new RPATH and RUNPATH strings.
  for(int i=0; i < rp_count; ++i)
    {
    // Seek to the RPATH position.
    if(!f.seekp(rp[i].Position))
      {
      if(emsg)
        {
        *emsg = "Error seeking to ";
        *emsg += rp[i].Name;
        *emsg += " position.";
        }
      return false;
      }

    // Write the new rpath.  Follow it with enough null terminators to
    // fill the string table entry.
    f << rp[i].Value;
    for(unsigned long j=rp[i].Value.length(); j < rp[i].Size; ++j)
      {
      f << '\0';
      }

    // Make sure it wrote correctly.
    if(!f)
      {
      if(emsg)
        {
        *emsg = "Error writing the new ";
        *emsg += rp[i].Name;
        *emsg += " string to the file.";
        }
      return false;
      }
    }
  }

  // Everything was updated successfully.
  if(changed)
    {
    *changed = true;
    }
  return true;
#else
  (void)file;
  (void)oldRPath;
  (void)newRPath;
  (void)emsg;
  (void)changed;
  return false;
#endif
}

//----------------------------------------------------------------------------
bool cmSystemTools::VersionCompare(cmSystemTools::CompareOp op,
                                   const char* lhss, const char* rhss)
{
  unsigned int lhs[4] = {0,0,0,0};
  unsigned int rhs[4] = {0,0,0,0};
  sscanf(lhss, "%u.%u.%u.%u", &lhs[0], &lhs[1], &lhs[2], &lhs[3]);
  sscanf(rhss, "%u.%u.%u.%u", &rhs[0], &rhs[1], &rhs[2], &rhs[3]);

  // Do component-wise comparison.
  for(unsigned int i=0; i < 4; ++i)
    {
    if(lhs[i] < rhs[i])
      {
      // lhs < rhs, so true if operation is LESS
      return op == cmSystemTools::OP_LESS;
      }
    else if(lhs[i] > rhs[i])
      {
      // lhs > rhs, so true if operation is GREATER
      return op == cmSystemTools::OP_GREATER;
      }
    }
  // lhs == rhs, so true if operation is EQUAL
  return op == cmSystemTools::OP_EQUAL;
}

//----------------------------------------------------------------------------
bool cmSystemTools::RemoveRPath(std::string const& file, std::string* emsg,
                                bool* removed)
{
#if defined(CMAKE_USE_ELF_PARSER)
  if(removed)
    {
    *removed = false;
    }
  int zeroCount = 0;
  unsigned long zeroPosition[2] = {0,0};
  unsigned long zeroSize[2] = {0,0};
  unsigned long bytesBegin = 0;
  std::vector<char> bytes;
  {
  // Parse the ELF binary.
  cmELF elf(file.c_str());

  // Get the RPATH and RUNPATH entries from it and sort them by index
  // in the dynamic section header.
  int se_count = 0;
  cmELF::StringEntry const* se[2] = {0, 0};
  if(cmELF::StringEntry const* se_rpath = elf.GetRPath())
    {
    se[se_count++] = se_rpath;
    }
  if(cmELF::StringEntry const* se_runpath = elf.GetRunPath())
    {
    se[se_count++] = se_runpath;
    }
  if(se_count == 0)
    {
    // There is no RPATH or RUNPATH anyway.
    return true;
    }
  if(se_count == 2 && se[1]->IndexInSection < se[0]->IndexInSection)
    {
    cmsys_stl::swap(se[0], se[1]);
    }

  // Get the size of the dynamic section header.
  unsigned int count = elf.GetDynamicEntryCount();
  if(count == 0)
    {
    // This should happen only for invalid ELF files where a DT_NULL
    // appears before the end of the table.
    if(emsg)
      {
      *emsg = "DYNAMIC section contains a DT_NULL before the end.";
      }
    return false;
    }

  // Save information about the string entries to be zeroed.
  zeroCount = se_count;
  for(int i=0; i < se_count; ++i)
    {
    zeroPosition[i] = se[i]->Position;
    zeroSize[i] = se[i]->Size;
    }

  // Get the range of file positions corresponding to each entry and
  // the rest of the table after them.
  unsigned long entryBegin[3] = {0,0,0};
  unsigned long entryEnd[2] = {0,0};
  for(int i=0; i < se_count; ++i)
    {
    entryBegin[i] = elf.GetDynamicEntryPosition(se[i]->IndexInSection);
    entryEnd[i] = elf.GetDynamicEntryPosition(se[i]->IndexInSection+1);
    }
  entryBegin[se_count] = elf.GetDynamicEntryPosition(count);

  // The data are to be written over the old table entries starting at
  // the first one being removed.
  bytesBegin = entryBegin[0];
  unsigned long bytesEnd = entryBegin[se_count];

  // Allocate a buffer to hold the part of the file to be written.
  // Initialize it with zeros.
  bytes.resize(bytesEnd - bytesBegin, 0);

  // Read the part of the DYNAMIC section header that will move.
  // The remainder of the buffer will be left with zeros which
  // represent a DT_NULL entry.
  char* data = &bytes[0];
  for(int i=0; i < se_count; ++i)
    {
    // Read data between the entries being removed.
    unsigned long sz = entryBegin[i+1] - entryEnd[i];
    if(sz > 0 && !elf.ReadBytes(entryEnd[i], sz, data))
      {
      if(emsg)
        {
        *emsg = "Failed to read DYNAMIC section header.";
        }
      return false;
      }
    data += sz;
    }
  }

  // Open the file for update.
  std::ofstream f(file.c_str(),
                  std::ios::in | std::ios::out | std::ios::binary);
  if(!f)
    {
    if(emsg)
      {
      *emsg = "Error opening file for update.";
      }
    return false;
    }

  // Write the new DYNAMIC table header.
  if(!f.seekp(bytesBegin))
    {
    if(emsg)
      {
      *emsg = "Error seeking to DYNAMIC table header for RPATH.";
      }
    return false;
    }
  if(!f.write(&bytes[0], bytes.size()))
    {
    if(emsg)
      {
      *emsg = "Error replacing DYNAMIC table header.";
      }
    return false;
    }

  // Fill the RPATH and RUNPATH strings with zero bytes.
  for(int i=0; i < zeroCount; ++i)
    {
    if(!f.seekp(zeroPosition[i]))
      {
      if(emsg)
        {
        *emsg = "Error seeking to RPATH position.";
        }
      return false;
      }
    for(unsigned long j=0; j < zeroSize[i]; ++j)
      {
      f << '\0';
      }
    if(!f)
      {
      if(emsg)
        {
        *emsg = "Error writing the empty rpath string to the file.";
        }
      return false;
      }
    }

  // Everything was updated successfully.
  if(removed)
    {
    *removed = true;
    }
  return true;
#else
  (void)file;
  (void)emsg;
  (void)removed;
  return false;
#endif
}

//----------------------------------------------------------------------------
bool cmSystemTools::CheckRPath(std::string const& file,
                               std::string const& newRPath)
{
#if defined(CMAKE_USE_ELF_PARSER)
  // Parse the ELF binary.
  cmELF elf(file.c_str());

  // Get the RPATH or RUNPATH entry from it.
  cmELF::StringEntry const* se = elf.GetRPath();
  if(!se)
    {
    se = elf.GetRunPath();
    }

  // Make sure the current rpath contains the new rpath.
  if(newRPath.empty())
    {
    if(!se)
      {
      return true;
      }
    }
  else
    {
    if(se &&
       cmSystemToolsFindRPath(se->Value, newRPath) != std::string::npos)
      {
      return true;
      }
    }
  return false;
#else
  (void)file;
  (void)newRPath;
  return false;
#endif
}

//----------------------------------------------------------------------------
bool cmSystemTools::RepeatedRemoveDirectory(const char* dir)
{
  // Windows sometimes locks files temporarily so try a few times.
  for(int i = 0; i < 10; ++i)
    {
    if(cmSystemTools::RemoveADirectory(dir))
      {
      return true;
      }
    cmSystemTools::Delay(100);
    }
  return false;
}

//----------------------------------------------------------------------------
std::vector<std::string> cmSystemTools::tokenize(const std::string& str,
                                  const std::string& sep)
{
  std::vector<std::string> tokens;
  std::string::size_type tokend = 0;

  do
    {
    std::string::size_type tokstart=str.find_first_not_of(sep, tokend);
    if (tokstart==std::string::npos)
      {
      break;    // no more tokens
      }
    tokend=str.find_first_of(sep,tokstart);
    if (tokend==std::string::npos)
      {
      tokens.push_back(str.substr(tokstart));
      }
    else
      {
      tokens.push_back(str.substr(tokstart,tokend-tokstart));
      }
    } while (tokend!=std::string::npos);

  if (tokens.empty())
    {
    tokens.push_back("");
    }
  return tokens;
}