I created a .h file for mysql connections. In my example file, I created an array of my class and made connection with the database for each subscript of the class object one by one. Then I checked if the connection in the previous subscripts are active or not, I found all the previous connection are disconnected.
I want to establish multiple connection with database at a time.
The server(and not the clients) will connect to the clients and just send a message. The idea is to be able to connect at each client a different time.
e.g every 10mins connect at client 1 every 2mins connect at client 2 every 1hour connect at client 3 and so on...
So how to implement this ? Should i create a new child process for each connection and what about the timing ? A pseudo code also will work.
I have to implemente the to_string method. Whats the fastest way? Stringstreams. But I have to use C++ without any headers, so I need to implement the stringstream class. How can an stringstream hold one float? An double? Hoq cqn I implement an strigstream myself?
I can't run my server immediately after closing it, it leaves some connection(zombies) leave open after the server is terminated. and i have to wait for some time to run the server again but immediately can't start the server
The Connection class holds the Database Connection ODBC Handle.
The Statement class holds the Statement Handle, there can be multiple per Connection. It is made and destroyed each time a query must be done on the DB.
Now I'm just wondering.
I have a multithreaded application.
Is keeping one Connection for one DB enough for the whole application? Where the different threads will make Statements based on that one Connection.Or is it better to keep a Connection per thread?
I want to develop an application which can host multiple views of explorer (window), where as each window is totally separate from others. So that I can have multiple desktop views through my single explorer. Any built in feature in .NET ?
I've been working on a function that works like a pipeline of a shell but receives a directory, go over it an search for every file to send it to a filter, something like this in bash "cat dir/* | cmd_1 | cmd_2 | ... | cmd_N", The only problem i have with the code is the redirection of the pipe descriptors.
Code:
int main(int argc, char* argv[]){ char** cmd; int Number_cmd; cmd = &(argv[2]); /*list of cmds*/ Number_cmd = argc-2; /*number of cmds*/ }
[code]....
The code is seems to work fine except when i run it with more than one command in example ("./filter DIR wc rev") in this case it returns
wc: standard input: Bad file descriptor wc: -: Bad file descriptor 0 0 0
I'm using multiple C++ files in one project for the first time. Both have need to include a protected (#ifndef) header file. However, when I do that, I get a multiple definition error.
From what I found from research, adding the word inline before the function fixes the error. Is this the right way to do this, and why does it work? Should I make a habbit of just declaring any function that might be used in two .cpp files as inline?
Say I have 5 vectors of unsigned char each of size 5. I want to take the max of each index and store it in a new vector. What is the most optimal way to accomplish this?
I am accepting the word from user and arranging it in ascending order like in dictionary in a file . I am doing this by comparing the user entered word from existing word in the file . All the word which is smaller then user entered word is copied to another file "temp.txt" , then the user word is printed and then the remaining word ( which are larger) from "abc.txt" to "temp.txt" . But program close as soon as i enter the second word
I got this issue to tackle which consists of using an FIR LPF filter to filter a wav file using C programming.
Till now I managed to tackle the filter part following this link: Implementation of FIR Filtering in C (Part 1) | Shawn's DSP Tutorials (I have my own filter co-efficients which have been produced using FDAtool on MATLAB and some other minor changes have been applied to match my requirements)
Now, the link shown does not compensate for files having a header. I have three wav files which need to be filtered. Thus I need to first extract the data from the header .. this was done using RIFFpad. Now that I have the data
Info from RIFFpad: fmt - Offset=20 ID=fmt
[Code].....
I've got this hint to start with: Each audio datasample inside the wav_files can be made up of a number of bytes and these bytes arestored in the little-endian order. Inside your program you have to change this to a big-endian order.
I'm given a project in college to use trees(AVL tree, to be specific) and file handling(not very conversant with it). But I'm not able to relate the two.
I only know that files can be used to store data. But in what way can trees and file handling be connected? I know how to implement trees but how to store it as such in files?
write a program as described below: program that reads in two integers (age, social security number). You should write functions that throw an out-of-range exception forage (no negative numbers)SSN (must be a 9-digit integer) My code is written below:
#include "std_lib_facilities_4.h" int main(){ int age = 0; int ssn = 0;
It is advisable not to throw the exception from destructor. Because if exception happens stack unwinding happens. suppose the destructor again throws the exception then on part of first exception again one exception is thrown and exceptions can not be handled at same time. This is what i read from stack over flow.
I have a date class and i overloaded operator >> to accept input in dd/mm/yyyy format. if i enter the wrong date format my program will crash. How do i do exception handling for this? How should i do the try part? and for catch, I'll just catch a date class variable?
Code: void operator >> (istream &is, clsDate &date) { string inputDate; is >> inputDate; int mm = stringToNumber(inputDate.substr(3,2)); // read 2 characters from character number 3 start int dd = stringToNumber(inputDate.substr(0,2)); // read 2 characters from character number 0 start int yy = stringToNumber(inputDate.substr(6,4)); // read 4 characters from character number 6 start
Here is my code. I am combining two words and sorting the merge word in alphbetical order. The compiler giving me warning error
Program:12:4: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat] Program:14:4: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[100]' [-Wformat]
I'ma firmware writing, and usually use only C language (not my decision, unfortunately!).In many application we've only a text display (2 rows 16 columns ascii char, or 4x20 or something else). But the question can be used also for semi graphics panel and so on.
I'm looking for an example / library / sourcecode to handling all the pages in the project. When the program start you've a 1st page (wth info abt release, hallo screen and so on), then with a arrows buttons you can navigate throught many pages. Some of these can be called by SW (or HW) events. (Button, alarm, end of job ...) In abt 20 year of experience3 I?ve seen many type of different code.
Each processor is going to delete some of the assigned numbers.Is there a 'standard' technique for merging the arrayparts at the end of the parallel section (in pthreads)? If there are a neater way of doing this with lists Im also interested in that.
Example: After parallel section array is 1,3,6,etc
This is what I have at the moment which works as I would like but wondering if there is a better way of handling? Currently just making sure I know linked-lists well enough.
what order a CPU would process the following arithmetic problem: 5 - (-9) = 14? Would the CPU recognize that the 'minus a minus' combination simply represents 5 + 9, and proceed with that addition, or would the CPU have to first calculate the 2's complement of -9, and then proceed to take the 2's complement of that first result in order to complete the calculation of the addition of the 'double negative'?
