processinfo.cpp

// #################################################################################################
//  ALib C++ Library
//
//  Copyright 2013-2025 A-Worx GmbH, Germany
//  Published under 'Boost Software License' (a free software license, see LICENSE.txt)
// #################################################################################################
#include "alib_precompile.hpp"
#if !defined(ALIB_C20_MODULES) || ((ALIB_C20_MODULES != 0) && (ALIB_C20_MODULES != 1))
#   error "Symbol ALIB_C20_MODULES has to be given to the compiler as either 0 or 1"
#endif
#if ALIB_C20_MODULES
    module;
#endif
// ======================================   Global Fragment   ======================================
#include "alib/system/system.prepro.hpp"
#if !DOXYGEN
#   if defined(__GLIBCXX__) || defined(_LIBCPP_VERSION) || defined(__ANDROID_NDK__)
#       include <unistd.h>
#       if defined(__APPLE__)
#           include <unistd.h>
#           include <sys/sysctl.h>
#           include <libproc.h>
#       endif
#   elif   defined( _WIN32 )
#      include <direct.h>
#   else
#      pragma message ("Unknown Platform in file: " __FILE__ )
#   endif
#   include <fstream>
#endif // !DOXYGEN
// ===========================================   Module   ==========================================
#if ALIB_C20_MODULES
    module ALib.System;
    import   ALib.Lang;
#   if !ALIB_SINGLE_THREADED
    import   ALib.Threads;
#   endif
    import   ALib.Strings;
    import   ALib.Strings.Tokenizer;
#else
#   include "ALib.Lang.H"
#   if !ALIB_SINGLE_THREADED
#    include "ALib.Threads.H"
#   endif
#   include "ALib.Strings.H"
#   include "ALib.Strings.Tokenizer.H"
#   include "ALib.System.H"
#endif
// ======================================   Implementation   =======================================
namespace alib {  namespace system {
 
// static instance representing current process
ProcessInfo    ProcessInfo::current;
 
#   include "ALib.Lang.CIFunctions.H"
const ProcessInfo&    ProcessInfo::Current()
{
    IF_ALIB_THREADS( static Lock   lock; ALIB_DBG(lock.Dbg.Name= "ProcessInfo";) )
    if( current.PID == 0 )
    {
        // Own global lock and check if still nulled.
        // (If not, this was a very unlikely parallel access )
        ALIB_LOCK_WITH( lock )
        if ( ProcessInfo::current.PID == 0 )
             ProcessInfo::current.get( 0 );
    }
    return current;
}
#   include "ALib.Lang.CIMethods.H"
 
 
#if defined(__GLIBC__) && defined(__unix__) || defined(__ANDROID_NDK__)
    bool readProcFile( const NCString& fileName, AString& result  );
    bool readProcFile( const NCString& fileName, AString& result  )
    {
        std::ifstream file( fileName );
 
        std::string buffer;
        getline(file, buffer);
 
        // spaces are replaced with '\0'. Revert this.
        if (buffer.size() > 2 )
            for( size_t i= 0 ; i < buffer.size() -2 ; ++i )
                if ( buffer[i] == '\0' )
                    buffer[i]= ' ';
 
        result.Reset( buffer.c_str() );
        file.close();
        return true;
    }
 
    bool ProcessInfo::getStatField( int fieldNo, AString& target)
    {
        Tokenizer tknzr( Stat, ' ');
        bool result= true;
        while ( --fieldNo >= 0 && (result= tknzr.HasNext()) )
            tknzr.Next();
 
        target.Reset( tknzr.Next() );
        return result;
    }
 
    bool ProcessInfo::get( uinteger pid )
    {
        // use current thread if no PID given
        uinteger newPID= 0;
        if ( pid == 0 )
        {
            auto np= getpid();
            if(np > 0 )
                newPID= uinteger( np );
        }
        else
            newPID= pid;
 
        if ( newPID == 0 )
            return false;
 
 
        PID= newPID;
 
        // cmdline, stat from proc
        NString64 procDir("/proc/");  procDir._<NC>( PID )._( '/' );
        integer    procPathLen= procDir.Length();
        {
            // read things
            procDir << "cmdline"; readProcFile( procDir,  CmdLine  );  procDir.ShortenTo(procPathLen);
            procDir << "stat";    readProcFile( procDir,  Stat     );  procDir.ShortenTo(procPathLen);
        }
 
        getStatField( 3, Name ); // PPID
        PPID= uinteger( Name.ParseInt() );
        getStatField( 1, Name );
        ALIB_ASSERT_ERROR(                 Name.IsEmpty()
                                ||   (     Name.Length() >= 2
                                        && Name.CharAtStart<NC>()=='('
                                        && Name.CharAtEnd  <NC>()==')' ),
                                "CAMP", "Error reading process Info"         )
 
        if ( Name.CharAtEnd  () == ')' ) Name.DeleteEnd  <NC>( 1 );
        if ( Name.CharAtStart() == '(' ) Name.DeleteStart<NC>( 1 );
        getStatField( 2, StatState );
        getStatField( 4, StatPGRP );
 
        // get executable path and name
        ExecFileName.Reset();
        ExecFilePath.Reset();
 
        procDir << A_CHAR("exe");
            nchar buffer[2048];
            ssize_t length= readlink( procDir, buffer, 2048 );
        procDir.ShortenTo(procPathLen);
 
        if( length > 0 )
        {
            ExecFilePath.Append( buffer, length );
            integer idx= ExecFilePath.LastIndexOf( '/' );
            ALIB_ASSERT_ERROR( idx>= 0, "CAMP",
                "Executable path does not contain directory separator character.\n"
                "  Path: {}", ExecFilePath )
            ExecFileName._( ExecFilePath, idx + 1 );
            ExecFilePath.ShortenTo( idx );
        }
        else
        {
            // obviously no rights to read the link. We use the process name
            ExecFileName._( Name );
        }
        return true;
    }
 
#elif defined (__APPLE__)
 
    bool ProcessInfo::get( uinteger pid )
    {
        PID= PPID= 0;
        if( pid == 0 )
            pid= uinteger( getpid() );
 
        struct proc_bsdinfo proc;
        int st = proc_pidinfo( int(pid), PROC_PIDTBSDINFO, 0, &proc, PROC_PIDTBSDINFO_SIZE);
        if (st != PROC_PIDTBSDINFO_SIZE)
            return false;
 
        // pid and parent pid
        PID=    pid;
        PPID=   uinteger( proc.pbi_ppid );
 
        // get name
        Name._(reinterpret_cast<const char*>( proc.pbi_comm ) );
 
        // get executable filename and path
        {
            char pathbuf[PROC_PIDPATHINFO_MAXSIZE];
 
            if ( proc_pidpath (int( PID ), pathbuf, PROC_PIDPATHINFO_MAXSIZE) > 0 )
            {
                ExecFilePath._( reinterpret_cast<const char*>( pathbuf ) );
                integer sepPos= ExecFilePath.LastIndexOf( '/' );
                if( sepPos > 0 )
                {
                    ExecFileName._(ExecFilePath, sepPos + 1 );
                    ExecFilePath.SetLength( sepPos );
                }
            }
        }
 
        return true;
    }
 
#elif defined (_WIN32)
 
    bool ProcessInfo::get( uinteger pid )
    {
        // get pid
        if (pid  != 0 )
            return false;
 
        DWORD wPID= GetCurrentProcessId();
        PID = (uinteger)  wPID;
 
 
        // get command line
        CmdLine.Reset( NString( GetCommandLineA()) );
 
        // get executable filename and path
        ExecFileName.Reset();
        ExecFilePath.Reset();
        Name.Reset();
 
        char buf[MAX_PATH];
        GetModuleFileNameA( NULL, buf, MAX_PATH );
        ExecFilePath.Reset( (const char*) buf );
        integer idx= ExecFilePath.LastIndexOf( '\\' );
        ALIB_ASSERT_ERROR( idx>= 0, "CAMP",
                           "Executable path does not contain directory separator character: ",
                           ExecFilePath )
        Name= ExecFileName._( ExecFilePath, idx + 1 );
        ExecFilePath.SetLength( idx );
 
        // get console title
        STARTUPINFOA startupInfo;
        GetStartupInfoA( &startupInfo );
        ConsoleTitle.Reset( NString(startupInfo.lpTitle) );
 
        return true;
    }
 
#else
    #pragma message ("Unknown Platform in file: " __FILE__ )
#endif
 
}} // namespace [alib::system]