C / C++ / MFC Discussion Boards

Re: How to insert char* to char array - WITHOUT using string

Victor Nijegorodov16-Dec-17 21:31

Victor Nijegorodov

16-Dec-17 21:31

Vaclav_ wrote:
What is interesting the parameter type passed to sprintf has to be %s "string" - not %c.

%c is used for a single character.
%s - for the char sequence.

Re: How to insert char* to char array - WITHOUT using string

Vaclav_20-Dec-17 7:25

Vaclav_

20-Dec-17 7:25

Read the details - I am passing SINGLE char.
Maybe passing %s includes hidden terminating charterer - hence "sequence ", but the description of the function calls %s a string not a sequence - which makes more sense.

Re: How to insert char* to char array - WITHOUT using string

jschell16-Dec-17 8:55

jschell

16-Dec-17 8:55

Vaclav_ wrote:
Any constructive help would be appreciated,

First since you are using C++ you should be using 'new'

Steps
1. Call the existing character array A. Call the data to insert S.
2. Determine the size of the NEW array that you need. Add A size plus size of S.
3. Use 'new' to create brand new character array using size from #1. Call this new array X.
4. Determine where you are going to insert the new data.
5. Copy from A into X up to the point where you want to insert
6. Copy all of S into X at the point where you STOPPED in #4
7. Copy the REMAINDER of A (what was left over in A from #4) into X at the point where you STOPPED in #6.

Result is now in X.

Re: How to insert char* to char array - WITHOUT using string

Richard MacCutchan16-Dec-17 9:51

Richard MacCutchan

16-Dec-17 9:51

Since this is C++ you should use the string class; that is what it is designed for.

modified 17-Dec-17 3:00am.

Re: How to insert char* to char array - WITHOUT using string

Munchies_Matt20-Dec-17 3:47

Munchies_Matt

20-Dec-17 3:47

So have a char array:

char* buf="/sys/class/gpio/gpioX/direction"

And set the value at 'X'

*buf+20 = <whatever you="" want="">

Re: How to insert char* to char array - WITHOUT using string

Vaclav_20-Dec-17 7:31

Vaclav_

20-Dec-17 7:31

Nice, but than I need to count the pointer where the insertion goes.
Which in my case is constant, so not big issue.
Thanks for your contribution .
Cheers

Re: How to insert char* to char array - WITHOUT using string

Munchies_Matt20-Dec-17 21:53

Munchies_Matt

20-Dec-17 21:53

You can always count backwards from the end, find the first / and insert the value before that.

String parsing like this, C style, is done a heck of a lot. It is light weight and very quick.

How know if a window is above another

Schehaider_Aymen15-Dec-17 5:46

Schehaider_Aymen

15-Dec-17 5:46

I have 2 windows, let's say a FileZilla window and a Notepad Window. And I have the FileZilla window is on the top of the Notepad one (like cards; on above the other).

I want to know how could I get the information that the FileZilla window is above the notepad's one ?

I tried GetWindowLong But no chance.

C++

LONG wndState1 = ::GetWindowLong(handler1, GWL_EXSTYLE);

C++

LONG wndState2 = ::GetWindowLong(handler2, GWL_EXSTYLE);

both results is equal to 256.

Is there a trick for that ?

"The Only Limit Is Only Your Imagination."

modified 15-Dec-17 11:52am.

Re: How know if a window is above another

Rick York15-Dec-17 6:09

Rick York

15-Dec-17 6:09

Try calling EnumDesktopWindows. I think it will give the window handles in their z-order to the callback function. I am not sure about this though. It would be fairly easy to contrive a test app to experiment with it. You might find EnumWindows will do it also. Between the two you should be able to determine what you want. Once you get the window handles in their z order you will have to determine which window is which, likely by their titles.

Re: How know if a window is above another

Victor Nijegorodov15-Dec-17 9:28

Victor Nijegorodov

15-Dec-17 9:28

this discussion could also help: c# - How to get the z-order in windows? - Stack Overflow

Re: How know if a window is above another

Schehaider_Aymen15-Dec-17 11:07

Schehaider_Aymen

15-Dec-17 11:07

I need smthing that works with c++. Smile | :)

"The Only Limit Is Only Your Imagination."

Re: How know if a window is above another

Richard Andrew x6416-Dec-17 3:15

Richard Andrew x64

16-Dec-17 3:15

If you can do C++, then you can surely translate from C#. Especially since the functions you need to call are right in the code. Roll eyes | :rolleyes:

The difficult we do right away...
...the impossible takes slightly longer.

Re: How know if a window is above another

leon de boer16-Dec-17 5:36

leon de boer

16-Dec-17 5:36

Windows API has the function GetTopWindow
GetTopWindow function (Windows)[^]

From the TopWindow you want walk down thru the chain via GetNextWindow
GetNextWindow function (Windows)[^]

So in your case you want to ask the topWindow of the window that contains both FileZilla window and a Notepad Window. You can then walk along the chain using GetNextWindow and see which is above which just by asking the window title.

Something like this will work

C++

char buf[256];
HWND Wnd = GetTopWindow( /*handle of window containing both*/ );
GetWindowText(Wnd, &buf[0], sizeof(buf));
while (Wnd != 0 && !stricmp(&buf[0], "FileZilla") && !stricmp(&buf[0], "NotePad"))
{
   Wnd = GetNextWindow(Wnd, GW_HWNDNEXT); // Next window
   GetWindowText(Wnd, &buf[0], sizeof(buf)); // Get it's title
}
if (Wnd == 0) {
   /* Error neither window found */
}
else {
   /* Wnd is the topmost of 2 windows title and the string title is in buf */  
}

It is equivalent to
EnumChildWindows function (Windows)[^]
However for the simplicity you have it isn't worth setting up the enumeration function.

In vino veritas

Frame or even Thread exception handler with _try _except/_catch()

ForNow15-Dec-17 3:22

ForNow

15-Dec-17 3:22

Is there an Api to implement exception handling on function/frame thread basis without the _try _except/_catch statements as that limits me to only certain type of exceptions

It would be nice to have an api on a function or frame Even on a thread basis

The function and the frame saves the programmer from doing unwinding

with AddVectoredExceptionHandler I catch everything but then I have to figure out from which function the exception occurred

Thanks

How to check session created or not in MySQL X DevApi A,k,a X Protocol.

lynxpravoka14-Dec-17 12:49

lynxpravoka

14-Dec-17 12:49

it's been 2 days. i'm struggle with this things. this's still new. the documented it just only help a bit. i want to check session created or not. a.k.a Connected or not. i don't know why the developer MySQL make new terms to call a thing. in this code. everytime i change something credential thing like host, port, user,pass. it return same. and return unexpected result with long zero 00000000000000 if use cout to sess. in my server i already enable X Plugin. my enviroment is Visual Studio Community 2017 c++ desktop.

C++

#include <iostream>
#include "mysql_xapi.h"

using namespace std;

int main()
{
// initiliziation 
	mysqlx_session_t  * sess;
	char conn_error[MYSQLX_MAX_ERROR_LEN];
	int err_code;
// open session. i use port 3306 cause this my mysql default port run. but in documented it says default port is 33060. i don't know it's seperate port to access. but when i change it to 33060. the result still same.

	sess = mysqlx_get_session("127.0.0.1", 3306, "root", "root", "test", conn_error, &err_code);

	if(!sess)
{
cout << "It's not connect";
}
else
{
cout << "It's connect";
}

// close session
	mysqlx_session_close(sess);
	return 0;
}

Re: How to check session created or not in MySQL X DevApi A,k,a X Protocol.

Jochen Arndt14-Dec-17 21:01

Jochen Arndt

14-Dec-17 21:01

The function provides an error code and an error message upon failure. So print those out to get information on what went wrong:

sess = mysqlx_get_session("127.0.0.1", 3306, "root", "root", "test", conn_error, &err_code);
if (NULL == sess)
{
    cout << "Connection failed; error " << err_code << ": " << conn_error << endl;
}

Re: How to check session created or not in MySQL X DevApi A,k,a X Protocol.

lynxpravoka15-Dec-17 2:34

lynxpravoka

15-Dec-17 2:34

The error nothing helping. it shows string unexpected result and integer 1.

can u figure out when the error like that? i think can't.

Re: How to check session created or not in MySQL X DevApi A,k,a X Protocol.

Jochen Arndt15-Dec-17 2:51

Jochen Arndt

15-Dec-17 2:51

I would expect a meaningful error message if one the parameters is wrong.

That generic message might indicate that it is networking problem. Because you are using localhost (127.0.0.1) it is probably not due to blocking by a firewall. You should check the port number and ensure that it is the port on which your server is listening.

Depending on the operating system, you might also us a command line utility to show listening ports (as root/adminstrator: Linux: lsof -nPi, Windows: netstat -ban).

C pre increment and post increment

Anonygeeker13-Dec-17 23:27

Anonygeeker

13-Dec-17 23:27

Hi,
int x=11;
printf("%d %d %d ", x++,++x,++x);

It prints 13 14 14, But I thought 13 14 15
Why ?

Re: C pre increment and post increment

Richard MacCutchan13-Dec-17 23:52

Richard MacCutchan

13-Dec-17 23:52

Because you should never use such expressions. The compiler writers are allowed to handle the order of incrementation in any way they like, so the results may or may not be what you expect. Bottom line: don't do it.

Re: C pre increment and post increment

Anonygeeker14-Dec-17 1:05

Anonygeeker

14-Dec-17 1:05

I agree. but my doubt was how it happens.

Re: C pre increment and post increment

Jochen Arndt14-Dec-17 0:01

Jochen Arndt

14-Dec-17 0:01

It is executed in this order here:

C++

// Pre-increment is executed first
++x; // 12
++x; // 13
// push first parameter on the stack: 13
push x; 
// post increment
x++; // 14
// push 2nd and 3rd parameter on the stack: 14
push x; 
push x;

Re: C pre increment and post increment

Anonygeeker14-Dec-17 1:05

Anonygeeker

14-Dec-17 1:05

Good explanation..Thanks

Re: C pre increment and post increment

leon de boer14-Dec-17 6:16

leon de boer

14-Dec-17 6:16

It isn't a good answer it's wrong the result is undefined.

Try it on VS2017 and you will likely get "13 13 13 " because of the way the optimizer works.

In vino veritas

Re: C pre increment and post increment

Daniel Pfeffer14-Dec-17 2:00

Daniel Pfeffer

14-Dec-17 2:00

This expression is undefined by the C Standard, meaning that the compiler can do anything with it, including formatting your disk or causing demons to fly out of your nose. You should consider yourself lucky that the compiler only incremented 'x' in a weird manner. Smile | :)

Note that even changing the compiler options (e.g. optimization) might change the printed results, so even if this "appears to work properly" on your system - DON'T DO IT!

(On comp.std.c and comp.lang.c they used to refer to a notional system, the DeathStation 9000, that would actually create Nasal Demons when it encountered undefined expressions Smile | :)

)

If you have an important point to make, don't try to be subtle or clever. Use a pile driver. Hit the point once. Then come back and hit it again. Then hit it a third time - a tremendous whack.

--Winston Churchill

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