/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM 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, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

InNamespace
    Foam

Description
    Functions used by OpenFOAM that are specific to POSIX compliant
    operating systems and need to be replaced or emulated on other systems.

SourceFiles
    POSIX.C

\*---------------------------------------------------------------------------*/

#ifndef OSspecific_H
#define OSspecific_H

#include "fileNameList.H"
#include "long.H"

#include <sys/types.h>

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#ifdef MSWIN
  // Match assumptions elsewhere.
  typedef long PID_T;
#else
  typedef pid_t PID_T;
#endif

//- Return the PID of this process
PID_T pid();

//- Return the parent PID of this process
PID_T ppid();

//- Return the group PID of this process
PID_T pgid();

//- Return true if environment variable of given name is defined
bool env(const word&);

//- Return environment variable of given name
//  Return string() if the environment is undefined
string getEnv(const word&);

//- Set an environment variable
bool setEnv(const word& name, const std::string& value, const bool overwrite);

//- Return the system's host name, as per hostname(1)
//  Optionally with the full name (as per the '-f' option)
string hostName(const bool full=false);

//- Return the system's domain name, as per hostname(1) with the '-d' option
string domainName();

//- Return the user's login name
string userName();

//- Is user administrator
bool isAdministrator();

//- Return home directory path name for the current user
fileName home();

//- Return home directory path name for a particular user
fileName home(const string& userName);

//- Return current working directory path name
fileName cwd();

//- Change the current directory to the one given and return true,
//  else return false
bool chDir(const fileName& dir);

//- Search for files from user/group/shipped directories.
//  The search scheme allows for version-specific and
//  version-independent files using the following hierarchy:
//  - \b user settings:
//    - ~/.OpenFOAM/\<VERSION\>
//    - ~/.OpenFOAM/
//  - \b group (site) settings (when $WM_PROJECT_SITE is set):
//    - $WM_PROJECT_SITE/\<VERSION\>
//    - $WM_PROJECT_SITE
//  - \b group (site) settings (when $WM_PROJECT_SITE is not set):
//    - $WM_PROJECT_INST_DIR/site/\<VERSION\>
//    - $WM_PROJECT_INST_DIR/site/
//  - \b other (shipped) settings:
//    - $WM_PROJECT_DIR/etc/
//
//  \return The list of full paths of all the matching files or
//  an empty list if the name cannot be found.
//  Optionally abort if the file cannot be found.
//  Optionally stop search after the first file has been found.
fileNameList findEtcFiles
(
    const fileName&,
    bool mandatory=false,
    bool findFirst=false
);

//- Search for a file using findEtcFiles.
//  \return The full path name of the first file found in the
//  search hierarchy or an empty fileName if the name cannot be found.
//  Optionally abort if the file cannot be found.
fileName findEtcFile(const fileName&, bool mandatory=false);

//- Make a directory and return an error if it could not be created
//  and does not already exist
bool mkDir(const fileName&, mode_t=0777);

//- Set the file mode
bool chMod(const fileName&, const mode_t);

//- Return the file mode
mode_t mode(const fileName&);

//- Return the file type: DIRECTORY or FILE
fileName::Type type(const fileName&);

//- Does the name exist (as DIRECTORY or FILE) in the file system?
//  Optionally enable/disable check for gzip file.
bool exists(const fileName&, const bool checkGzip=true);

//- Does the name exist as a DIRECTORY in the file system?
bool isDir(const fileName&);

//- Does the name exist as a FILE in the file system?
//  Optionally enable/disable check for gzip file.
bool isFile(const fileName&, const bool checkGzip=true);

//- Return size of file
off_t fileSize(const fileName&);

//- Return time of last file modification
time_t lastModified(const fileName&);

//- Read a directory and return the entries as a string list
fileNameList readDir
(
    const fileName&,
    const fileName::Type=fileName::FILE,
    const bool filtergz=true
);

//- Copy, recursively if necessary, the source to the destination
bool cp(const fileName& src, const fileName& dst);

//- Create a softlink. dst should not exist. Returns true if successful.
bool ln(const fileName& src, const fileName& dst);

//- Rename src to dst
bool mv(const fileName& src, const fileName& dst);

//- Rename to a corresponding backup file
//  If the backup file already exists, attempt with "01" .. "99" suffix
bool mvBak(const fileName&, const std::string& ext = "bak");

//- Remove a file, returning true if successful otherwise false
bool rm(const fileName&);

//- Remove a dirctory and its contents
bool rmDir(const fileName&);

//- Sleep for the specified number of seconds
unsigned int sleep(const unsigned int);

//- Close file descriptor
void fdClose(const int);

//- Check if machine is up by pinging given port
bool ping(const string&, const label port, const label timeOut);

//- Check if machine is up by pinging port 22 (ssh) and 222 (rsh)
bool ping(const string&, const label timeOut=10);

//- Execute the specified command
int system(const std::string& command);

//- open a shared library. Return handle to library. Print error message
//  if library cannot be loaded (check = true)
void* dlOpen(const fileName& lib, const bool check = true);

//- Close a dlopened library using handle. Return true if successful
bool dlClose(void*);

//- Lookup a symbol in a dlopened library using handle to library
void* dlSym(void* handle, const std::string& symbol);

//- Report if symbol in a dlopened library could be found
bool dlSymFound(void* handle, const std::string& symbol);

//- Return all loaded libraries
fileNameList dlLoaded();


// Low level random numbers. Use Random class instead.

//- Seed random number generator.
void osRandomSeed(const label seed);

//- Return random integer (uniform distribution between 0 and 2^31)
label osRandomInteger();

//- Return random double precision (uniform distribution between 0 and 1)
scalar osRandomDouble();

//- Convert to unix path separators
std::string toUnixPath(const std::string& path);

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#endif

// ************************************************************************* //
