Re: Truncate a number with decimals - C / C++ / MFC Discussion Boards

toxcct5-Mar-08 4:10

5-Mar-08 4:10

the problem is how deque and vector manage their own internal buffers.

the way vector allocates its memory is like this: if you create an empty vector, it automatically reserves the amount of memory for 10 elements (if I remember well). vector has another constructor to tell it another starting reserved memory.

if you never use reserve(), vector will manage its internal buffer alone, and you have to know that its size doesn't increase constantly.
for example (and that's just an example - it may differ from implementations):

class T {};
 
std::vector<T> v = vector<T>();    //capacity = 5, lenght = 0
v.pushback(T());                   //capacity = 5, lenght = 1
v.pushback(T());                   //capacity = 5, lenght = 2
v.pushback(T());                   //capacity = 5, lenght = 3
v.pushback(T());                   //capacity = 5, lenght = 4
v.pushback(T());                   //capacity = 5, lenght = 5
v.pushback(T());                   //capacity = 10, lenght = 6
v.pushback(T());                   //capacity = 10, lenght = 7
v.pushback(T());                   //capacity = 10, lenght = 8
v.pushback(T());                   //capacity = 10, lenght = 9
v.pushback(T());                   //capacity = 10, lenght = 10

as you see, vector has a buffer which doesn't always grow when inserting a new element.
the advantage of this is that it ensures that all the elements in the vector are adjacent.
the inconvenient is that when you insert or delete elements in the middle of the container, it has to move every other elements after the position you insert/delete, thus reallocation.

deque work in a totally different way.
all elements are not adjacent in memory. deque is a linked list, that means each element is somewhere in memory, and has a pointer to the next (and previous) element. so, when you insert an element in a deque, you just have to new it, and change the pointers to incorporate the new element.
same with deletion. you just have to change the pointers of the previous (and next) elements to point now on each others, jumping the element we're deleting...

so, with a deque, the length() is always the allocated amount of memory, that why the writer said that "none of the allocations are redundant"...

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modified on Thursday, March 6, 2008 3:16 AM

Re: redundant allocation

George_George5-Mar-08 18:29

George_George

5-Mar-08 18:29

Hi toxcct,

I agree and understand your analysis. For the below comments from you,

toxcct wrote:
when you insert of delete elements in the middle of the container

It should be "when you insert or delete elements in the middle of the container"? A typo?

regards,
George

Re: redundant allocation

toxcct5-Mar-08 21:16

toxcct

5-Mar-08 21:16

George_George wrote:
It should be "when you insert or delete elements in the middle of the container"? A typo?

yes

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Re: redundant allocation

George_George5-Mar-08 21:39

George_George

5-Mar-08 21:39

Thanks toxcct,

Question answered.

regards,
George

Truncate a number with decimals

piul5-Mar-08 1:57

piul

5-Mar-08 1:57

There goes an easy one:

How do I truncate a double number (I've been looking about but haven't find a way) but leaving some decimal digits. For example:

double x = 345.2214455; to x = 345.2214;

Thanks a lot

Re: Truncate a number with decimals

Cedric Moonen5-Mar-08 2:02

Cedric Moonen

5-Mar-08 2:02

For which purpose do you want to truncate it ? Do you want to convert it to a string and display it somewhere ? If that's the case, you can use sprintf and specify the precision:

double x = 345.2214455;<br />
char szBuffer[255];<br />
sprintf(szBuffer,"%.4f",x);

Cédric Moonen
Software developer

Charting control [v1.3 - Updated]

Re: Truncate a number with decimals

piul5-Mar-08 2:06

piul

5-Mar-08 2:06

I want to compare to numbers, for example:

2.0024334 and 2.0024992 should be seen as equal because the first 4 decimals are the same.

And I want to be able to select the number of decimals that are taken into account

Re: Truncate a number with decimals

CPallini5-Mar-08 2:13

CPallini

5-Mar-08 2:13

piul wrote:
2.0024334 and 2.0024992 should be seen as equal because the first 4 decimals are the same.

Then the best way is

double x = 2.0024334;
double y = 2.0024992;
const double EPS = .0001;
if ( fabs(x-y) < EPS )
{ // the numbers are equal within give precision
  //...
}
else
{ // the numbers are different
  //...
}

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

Re: Truncate a number with decimals

CPallini5-Mar-08 2:09

CPallini

5-Mar-08 2:09

double x = 345.2214455;
x = floor(x * 10000)/10000;

double x = 345.2214455;
x = ((int)( x * 10000)) / 10000.0;

Please note:

(1) Care should be taken with negative values.
(2) The truncation is not exact (due to double numbers nature)

Smile | :)

Re: Truncate a number with decimals

piul5-Mar-08 2:14

piul

5-Mar-08 2:14

Thank you very much

Re: Truncate a number with decimals

CPallini5-Mar-08 2:17

CPallini

5-Mar-08 2:17

That don't work for you, see http://www.codeproject.com/script/Forums/View.aspx?fid=1647&msg=2452741[^].
Smile | :)

Re: Truncate a number with decimals

Eric Pruneau5-Mar-08 5:33

Eric Pruneau

5-Mar-08 5:33

The easiest way is certainly doing something like

double x = 345.2214455;
long tmp = static_cast<long>(x*10000);
x = tmp/10000.0;

Problem with Release Mode

ritz12345-Mar-08 1:49

ritz1234

5-Mar-08 1:49

Hello friends.

The exe of my project works well in Debug mode and has some problem in

Release mode and it shows the messagebox to tell the microsoft about this

problem with send and don't send buttons.

Could you tell me the problems that could be arrived if I want to distribute the debug version of my application what care should be taken?

ritz1234

Re: Problem with Release Mode

Cedric Moonen5-Mar-08 2:00

Cedric Moonen

5-Mar-08 2:00

ritz1234 wrote:
Could you tell me the problems that could be arrived if I want to distribute the debug version of my application what care should be taken?

Legally you can't distribute a debug version of your program. Anyway, if the release version crashes, it means that something is wrong and that your code is not totally stable. You should try to fix that instead.

Here is a great link about surviving the release version.[^]

Cédric Moonen
Software developer

Charting control [v1.3 - Updated]

Re: Problem with Release Mode

CPallini5-Mar-08 2:00

CPallini

5-Mar-08 2:00

Don't distribute the Debug version, fix the Release one, it shouldn't be so difficult.
See [^] and [^].
Smile | :)

Re: Problem with Release Mode

_AnsHUMAN_ 5-Mar-08 2:01

_AnsHUMAN_

5-Mar-08 2:01

See Here[^]

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

How to get the username associated with a process using win32 apis

vineeshV5-Mar-08 1:24

vineeshV

5-Mar-08 1:24

In my project (i am using visual studio 2005 ) i need to simulate the task manager model. i can able to extract all the informations using
CreateToolhelp32Snapshot .But i was unable to identify the username assoicated with the processes .Is any APIs are there for it? or any other way to achieve this ?

vineesh

Re: How to get the username associated with a process using win32 apis

Rajkumar R5-Mar-08 3:11

Rajkumar R

5-Mar-08 3:11

May be the following useful,

PSECURITY_DESCRIPTOR pSecurityDescriptor = NULL;
	PSID psidOwner = NULL;
	TCHAR lpName[256];
	TCHAR lpReferencedDomainName[256];
	SID_NAME_USE eUse;

	if (ERROR_SUCCESS == GetSecurityInfo(
		GetCurrentProcess(),// HANDLE handle,
		SE_KERNEL_OBJECT, //SE_OBJECT_TYPE ObjectType,
		OWNER_SECURITY_INFORMATION, //SECURITY_INFORMATION SecurityInfo,
		&psidOwner, //PSID* ppsidOwner,
		NULL, //PSID* ppsidGroup,
		NULL, //PACL* ppDacl,
		NULL, //PACL* ppSacl,
		&pSecurityDescriptor // PSECURITY_DESCRIPTOR* ppSecurityDescriptor
		))
	{

		DWORD cchName  = 256;
		DWORD cchReferencedDomainName  = 256;
		if (LookupAccountSid(
			NULL, // LPCTSTR lpSystemName,
			psidOwner, //PSID lpSid,
			lpName, //LPTSTR lpName,
			&cchName, //LPDWORD cchName,
			lpReferencedDomainName, //LPTSTR lpReferencedDomainName,
			&cchReferencedDomainName, //LPDWORD cchReferencedDomainName,
			&eUse //PSID_NAME_USE peUse
			))
		{
			CString Msg;
			Msg.Append(_T("User Name : "));
			Msg.Append(lpName);
			Msg.Append(_T("  Domain Name : "));
			Msg.Append(lpReferencedDomainName);
			MessageBox(Msg);
		}
		LocalFree(pSecurityDescriptor);
	}

Re: How to get the username associated with a process using win32 apis

vineeshV9-Mar-08 23:45

vineeshV

9-Mar-08 23:45

Thanks rajakumar ,

But the above gives me the username associated with the current process . My program should capture all the process ,their process id and the user name associated with them . Can you suggest any thing of the sort ?..

vineesh

Re: How to get the username associated with a process using win32 apis

Rajkumar R10-Mar-08 0:02

Rajkumar R

10-Mar-08 0:02

Your question was to get the username associated with a process,

GetSecurityInfo(
GetCurrentProcess(),// HANDLE handle,
what is restricting you to change the process handle used here. Does the code snippet i given is readonly?

vineeshV wrote:
My program should capture all the process ,their process id and the user name associated with them .

if you have handle to process (as you said in your original post), getting process id (DWORD GetProcessId(HANDLE Process)), getting user name as above.

if you are not having handles to all process, use EnumProcesses() API.

Re: How to get the username associated with a process using win32 apis

vineeshV10-Mar-08 1:01

vineeshV

10-Mar-08 1:01

Here is my code snippets ... it will works for the process having the username and domain attached to them having the same value for the user from the exe is called ...

#include <windows.h>
#include <tlhelp32.h>
#include <tchar.h>
#include <stdio.h>
#include <Aclapi.h>

// Forward declarations:

BOOL GetProcessList();
BOOL ListProcessModules( DWORD dwPID );
BOOL ListProcessThreads( DWORD dwOwnerPID );
void printError( TCHAR* msg );
void getuserProcess(HANDLE);
char filename[250];
DWORD pid = 0;
int isAlive = 0;
void main( )
{
GetProcessList();
getchar();

}

BOOL GetProcessList()
{
HANDLE hProcessSnap;
HANDLE hProcess;
PROCESSENTRY32 pe32;
DWORD dwPriorityClass;
HANDLE userhp;

// Take a snapshot of all processes in the system.
hProcessSnap = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );
if( hProcessSnap == INVALID_HANDLE_VALUE )
{
printError( TEXT("CreateToolhelp32Snapshot (of processes)") );
return( FALSE );
}

// Set the size of the structure before using it.
pe32.dwSize = sizeof( PROCESSENTRY32 );

// Retrieve information about the first process,
// and exit if unsuccessful
if( !Process32First( hProcessSnap, &pe32 ) )
{
printError( TEXT("Process32First") ); // show cause of failure
CloseHandle( hProcessSnap ); // clean the snapshot object
return( FALSE );
}

// Now walk the snapshot of processes, and
// display information about each process in turn
do
{
isAlive =1 ;

dwPriorityClass = 0;

printf("\n-----------ProcessName [%s]\n ",pe32.szExeFile);
printf( "\n Process ID = %04d", pe32.th32ProcessID );
pid = pe32.th32ProcessID;
printf( "\n Thread count = %d", pe32.cntThreads );
printf( "\n Parent process ID = %d", pe32.th32ParentProcessID );
printf( "\n Priority base = %d", pe32.pcPriClassBase );
if( dwPriorityClass )
printf( "\n Priority class = %d", dwPriorityClass );
userhp = OpenProcess( PROCESS_ALL_ACCESS, TRUE, pe32.th32ProcessID );

getuserProcess(userhp);

} while( Process32Next( hProcessSnap, &pe32 ) );

CloseHandle( hProcessSnap );

return 0;
}

void getuserProcess( HANDLE pid)
{
PSECURITY_DESCRIPTOR pSecurityDescriptor = NULL;
PSID psidOwner = NULL; TCHAR lpName[256];
TCHAR lpReferencedDomainName[256];
SID_NAME_USE eUse;
if (ERROR_SUCCESS == GetSecurityInfo(pid,//GetCurrentProcess(),// HANDLE handle,
SE_KERNEL_OBJECT, //SE_OBJECT_TYPE ObjectType,
OWNER_SECURITY_INFORMATION, //SECURITY_INFORMATION SecurityInfo,
&psidOwner, //PSID* ppsidOwner,
NULL, //PSID* ppsidGroup,
NULL, //PACL* ppDacl,
NULL, //PACL* ppSacl,
&pSecurityDescriptor // PSECURITY_DESCRIPTOR* ppSecurityDescriptor
))
{ DWORD cchName = 256;
DWORD cchReferencedDomainName = 256;
if (LookupAccountSid( NULL, // LPCTSTR lpSystemName,
psidOwner, //PSID lpSid,
lpName, //LPTSTR lpName,
&cchName, //LPDWORD cchName,
lpReferencedDomainName, //LPTSTR lpReferencedDomainName,
&cchReferencedDomainName, //LPDWORD cchReferencedDomainName,
&eUse //PSID_NAME_USE peUse
))
{

printf("UserName is [%s]",lpName);
printf("UserDomain is [%s]",lpReferencedDomainName);
LocalFree(pSecurityDescriptor);
}

}
}

void printError( TCHAR* msg )
{
DWORD eNum;
TCHAR sysMsg[256];
TCHAR* p;

eNum = GetLastError( );
FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, eNum,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
sysMsg, 256, NULL );

// Trim the end of the line and terminate it with a null
p = sysMsg;
while( ( *p > 31 ) || ( *p == 9 ) )
++p;
do { *p-- = 0; } while( ( p >= sysMsg ) &&
( ( *p == '.' ) || ( *p < 33 ) ) );

// Display the message
_tprintf( TEXT("\n WARNING: %s failed with error %d (%s)"), msg, eNum, sysMsg );

}

and a sample output
-----------------------

Process ID = 1604
Thread count = 9
Parent process ID = 268
Priority base = 8
-----------ProcessName [UMCSTUB.EXE]

Process ID = 1632
Thread count = 5
Parent process ID = 268
Priority base = 8
-----------ProcessName [dfssvc.exe]

Process ID = 1760
Thread count = 3
Parent process ID = 268
Priority base = 8
-----------ProcessName [msdtc.exe]

Process ID = 1780
Thread count = 23
Parent process ID = 268
Priority base = 8
-----------ProcessName [rcHost.exe]

Process ID = 1844
Thread count = 9
Parent process ID = 268
Priority base = 10
-----------ProcessName [svchost.exe]

Process ID = 1812
Thread count = 10
Parent process ID = 268
Priority base = 8
-----------ProcessName [DLLHOST.EXE]

Process ID = 3056
Thread count = 8
Parent process ID = 500
Priority base = 8
-----------ProcessName [CAF.exe]

Process ID = 3052
Thread count = 33
Parent process ID = 268
Priority base = 8
-----------ProcessName [cfsmsmd.exe]

Process ID = 1708
Thread count = 15
Parent process ID = 3052
Priority base = 8
-----------ProcessName [ccnfAgent.exe]

Process ID = 3044
Thread count = 5
Parent process ID = 3052
Priority base = 8
-----------ProcessName [cfnotsrvd.exe]

Process ID = 2284
Thread count = 17
Parent process ID = 3052
Priority base = 8
-----------ProcessName [ccsmagtd.exe]

Process ID = 2952
Thread count = 7
Parent process ID = 3052
Priority base = 8
-----------ProcessName [rcHost.exe]

Process ID = 2376
Thread count = 8
Parent process ID = 3052
Priority base = 13
-----------ProcessName [amswmagt.exe]

Process ID = 2408
Thread count = 7
Parent process ID = 3052
Priority base = 8
-----------ProcessName [capmuamagt.exe]

Process ID = 2468
Thread count = 4
Parent process ID = 3052
Priority base = 8
-----------ProcessName [cfFTPlugin.exe]

Process ID = 1644
Thread count = 7
Parent process ID = 3052
Priority base = 8
-----------ProcessName [dm_primer.exe]

Process ID = 2720
Thread count = 4
Parent process ID = 780
Priority base = 8
-----------ProcessName [CMD.EXE]

Process ID = 0572
Thread count = 1
Parent process ID = 3308
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [nlnotes.exe]

Process ID = 3352
Thread count = 24
Parent process ID = 3672
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [ntaskldr.exe]

Process ID = 3724
Thread count = 8
Parent process ID = 3352
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [explorer.exe]

Process ID = 3376
Thread count = 14
Parent process ID = 212
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [MSDEV.EXE]

Process ID = 1700
Thread count = 10
Parent process ID = 3376
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [editplus.exe]

Process ID = 3176
Thread count = 4
Parent process ID = 3376
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [IEXPLORE.EXE]

Process ID = 3636
Thread count = 16
Parent process ID = 3376
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [abc.exe]

Process ID = 3480
Thread count = 4
Parent process ID = 3376
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [VCSPAWN.EXE]

Process ID = 3356
Thread count = 1
Parent process ID = 1700
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]
-----------ProcessName [filops.exe]

Process ID = 1088
Thread count = 1
Parent process ID = 3356
Priority base = 8UserName is [vineesh.v]UserDomain is [POLARIS]

---------------------------------------------------------------------

The process having user as system are failed ...

vineesh

Re: How to get the username associated with a process using win32 apis

Rajkumar R10-Mar-08 4:24

Rajkumar R

10-Mar-08 4:24

Try the following which adjust the current process priviledge to get remote process info.

HANDLE hToken = NULL;
	if (OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES, 
               &hToken))
	{
		if (SetPrivilege(hToken, SE_DEBUG_NAME, TRUE))
		{
			HANDLE hProcess = OpenProcess( READ_CONTROL | ACCESS_SYSTEM_SECURITY , 
                        TRUE, dwprocessID);
			if (hProcess)
			{
				getuserProcess(hProcess);
				CloseHandle(hProcess);
			}
			SetPrivilege(hToken, SE_DEBUG_NAME, FALSE);
		}
		CloseHandle(hToken);
	}

SetPrivilege function is here[^]

Re: How to get the username associated with a process using win32 apis

Rajkumar R10-Mar-08 4:45

Rajkumar R

10-Mar-08 4:45

And have a look at Process Viewer[^], i just searched CP.

cacls cmd equivalent in win32

dharani4-Mar-08 23:13

dharani

4-Mar-08 23:13

Hi all
Could anyone please let me know whats the equivalent API for "cacls command" ?
(cacls is used to modify the user rights settings on a file)

As of now I use ShellExecute to run the batch file which contains this cmd . I would like to avoid using batch file .

Thanks in advance .

redindian

Re: cacls cmd equivalent in win32

Rajkumar R4-Mar-08 23:25

Rajkumar R

4-Mar-08 23:25

Haven't you searched msdn Access Control Lists[^]

dharani wrote:
As of now I use ShellExecute to run the batch file which contains this cmd . I would like to avoid using batch file .

If so, why don't you execute the command directly using ShellExecute without a batch file.

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