processinfo.hpp

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//==================================================================================================
/// \file
/// This header-file is part of module \alib_system of the \aliblong.
///
/// Copyright 2013-2026 A-Worx GmbH, Germany.
/// Published under #"mainpage_license".
//==================================================================================================
ALIB_EXPORT namespace alib { namespace  system {
 
//==================================================================================================
/// This class represents process information
//==================================================================================================
class ProcessInfo {
  //################################################################################################
  // Fields
  //################################################################################################
  protected:
        /// Information on the current process. This is initialized once, with the first invocation
        /// of #"Current".
        ALIB_DLL static ProcessInfo    current;
 
  public:
    /// The process id as AString.
    uinteger    PID;
 
    /// The command-line which invoked this process.
    AString     CmdLine;
 
    /// The name of the process.<br> Under GNU/Linux this is read from /proc/nnn/stat and may
    /// differ from #"ExecFileName". Under Windows OS, it is he same as field #"ExecFileName".
    AString     Name;
 
    /// The path of the executable (if available to us).
    AString     ExecFilePath;
 
    /// The file name of the executable (excluding #"ExecFilePath"). Under GNU/Linux,
    /// if we have no access to read that value, field #"ExecFilePath" will be empty
    /// while this field is filled with #".Name".
    AString     ExecFileName;
 
  //################################################################################################
  // Fields under unix like OS
  //################################################################################################
    #if defined( __unix__ )  || DOXYGEN
 
    /// The parent's process id as AString. (Unix like OS / Mac OS only.)
    uinteger    PPID;
 
    /// The contents of /proc/PID/stat file. (Unix like OS only.)
    AString     Stat;
 
    /// The state field (2) within #"Stat". (Unix like OS only.)
    AString     StatState;
 
    /// The process group field (4) within #"Stat". (Unix like OS only.)
    AString     StatPGRP;
    #endif
 
  //################################################################################################
  // Fields under Mac OS
  //################################################################################################
    #if defined( __APPLE__ )
            uinteger    PPID;
    #endif
 
  //################################################################################################
  // Fields under Windows OS
  //################################################################################################
    #if defined( _WIN32 ) || DOXYGEN
        public:
 
             /// For console processes, this is the title displayed in the title bar. (Windows OS only.)
            AString     ConsoleTitle;
    #endif
 
 
  //################################################################################################
  // Protected methods
  //################################################################################################
  protected:
    /// Default constructor to create an empty instance
    ProcessInfo()                                                                                 {}
 
 
    #if defined( __unix__ )
    /// Reads a field from the data found in /proc/PID/stat.
    /// @param fieldNo  The field number to read
    /// @param target   The variable to store the result in
    /// @returns \c true if successful.
    bool        getStatField( int fieldNo, AString& target );
    #endif
 
    /// Internal get() method with different platform implementations.
    ///
    /// @param PID  The ID of the process information is requested on.
    ///             If a \e nulled string is provided, the current process is addressed.
    ///
    /// @return \c true on success, \c false otherwise.
    ALIB_DLL bool  get( uinteger PID  );
 
  //################################################################################################
  // Interface
  //################################################################################################
  public:
    #if defined( __unix__ ) || defined(__APPLE__)
    /// Constructor that initializes this instance according to the process information
    /// received from the system.
    ///
    /// \note
    ///   This method is implemented for Unix like OS (incl. Mac OS) only.
    ///   On Windows OS, only information about the current process can be received
    ///   using static method #"Current".
    ///
    /// @param processID    The ID of the process information is requested on.
    ///                     If a \e nulled string is provided, the current process is
    ///                     addressed.
    ProcessInfo( uinteger processID  )                                         { get( processID ); }
 
    /// Fills the fields of this instance according to the process information received from
    /// the system.
    ///
    /// \note
    ///   This method is implemented for Unix like OS (incl. Mac OS) only.
    ///   On Windows OS, only information about the current process can be received
    ///   using static method #"Current".
    ///
    /// @param processID  The ID of the process information is requested on.
    ///                   If a \e nulled string is provided, the current process is
    ///                   addressed.
    ///
    /// @return \c true on success, \c false otherwise.
    ALIB_DLL bool          Get( uinteger processID  )                   { return get( processID ); }
    #endif
 
    /// Static method that receives information on the current process.
    ///
    /// @return A constant reference to a #"%ProcessInfo" object representing the current process.
    ALIB_DLL static
    const ProcessInfo&         Current();
};
 
} // namespace [ system]
 
/// Type alias in namespace #"%alib".
using     ProcessInfo=        system::ProcessInfo;
 
} // namespace [alib]