/*++

Module Name:

    uptime.c

Abstract:

    This implements the unix "uptime" utility.

Author:

    Michael Wookey 30-Nov-2002 (ntutils@wookey.org)

Compiler:

    VC7

Build:

    cl uptime.c

--*/

#define UNICODE

#define STRICT

#define WIN32_LEAN_AND_MEAN

#include <windows.h>

#include <stdio.h>

//

// Structures required for NtQuerySystemInformation and RtlTimeToElapsedTimeFields.

//

typedef struct _SYSTEM_TIMEOFDAY_INFORMATION

{

    LARGE_INTEGER BootTime;

    LARGE_INTEGER CurrentTime;

    LARGE_INTEGER TimeZoneBias;

    ULONG CurrentTimeZoneId;

} 

SYSTEM_TIMEOFDAY_INFORMATION, *PSYSTEM_TIMEOFDAY_INFORMATION;

typedef struct _TIME_FIELDS 

{

    SHORT Year;

    SHORT Month;

    SHORT Day;

    SHORT Hour;

    SHORT Minute;

    SHORT Second;

    SHORT Milliseconds;

    SHORT Weekday;

} 

TIME_FIELDS, *PTIME_FIELDS;

//

// The information class that we are querying via NtQuerySystemInformation.

//

typedef enum _SYSTEM_INFORMATION_CLASS 

{

    SystemTimeOfDayInformation = 3

} 

SYSTEM_INFORMATION_CLASS;

//

// Function definitions. These are exported from ntdll.dll

//

typedef LONG ( NTAPI *pNtQuerySystemInformation )

    (

    IN  SYSTEM_INFORMATION_CLASS SystemInformationClass,

    OUT PVOID SystemInformation,

    IN  ULONG SystemInformationLength,

    OUT PULONG ReturnLength OPTIONAL 

    );

typedef VOID ( NTAPI *pRtlTimeToElapsedTimeFields )

    (

    IN  PLARGE_INTEGER Time, 

    OUT PTIME_FIELDS TimeFields 

    );

INT

CDECL

wmain( 

    IN INT Argc, 

    IN PWCHAR Argv[], 

    IN PWCHAR Envp[] 

    )

{

    TIME_FIELDS UpTime = { 0 };

    LARGE_INTEGER TimeNow = { 0 };

    SYSTEM_TIMEOFDAY_INFORMATION TimeOfDay = { 0 };

    SYSTEMTIME ClockTime = { 0 };

    WCHAR ClockString[64];

    pNtQuerySystemInformation NtQuerySystemInformation = 0;

    pRtlTimeToElapsedTimeFields RtlTimeToElapsedTimeFields = 0;

    UNREFERENCED_PARAMETER( Argc );

    UNREFERENCED_PARAMETER( Argv );

    UNREFERENCED_PARAMETER( Envp );

    //

    // Obtain the function pointers. NtDll is implicitly mapped into

    // our process space.

    //

    NtQuerySystemInformation = (pNtQuerySystemInformation) 

        GetProcAddress( GetModuleHandleW( L"ntdll" ), "NtQuerySystemInformation" );

    RtlTimeToElapsedTimeFields = (pRtlTimeToElapsedTimeFields) 

        GetProcAddress( GetModuleHandleW( L"ntdll" ), "RtlTimeToElapsedTimeFields" );

    //

    // Obtain the time information from the system.

    //

    NtQuerySystemInformation( 

        SystemTimeOfDayInformation,

        &TimeOfDay,

        sizeof TimeOfDay,

        0 );

    //

    // Calculate the delta between the current time and the boot time.

    //

    TimeNow.QuadPart = TimeOfDay.CurrentTime.QuadPart - TimeOfDay.BootTime.QuadPart;

    //

    // Convert the time.

    //

    RtlTimeToElapsedTimeFields( &TimeNow, &UpTime );

    //

    // Get the current wall time.

    //

    GetLocalTime( &ClockTime );

    //

    // Format the current wall time.

    //

    GetTimeFormatW( 

        LOCALE_USER_DEFAULT, 

        0, 

        &ClockTime, 

        L"HH':'mm':'ss", 

        ClockString, 

        64 );

    //

    // Output to the console.

    //

    wprintf( L"%s, up %d day(s), %d:%02d:%02d",

        ClockString,

        UpTime.Day,

        UpTime.Hour,

        UpTime.Minute,

        UpTime.Second );

    return 0;

}

/* EOF */