C :: Redirecting Multiple Pipes With Multiple Children
Mar 21, 2014
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 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'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?
My professor asked my to make a program that makes the "FCFS","SWJ" operations using any programming language actually i preferred c++ i like it more than java so i started in it but i'm facing a little problem ,,, which is i cant enter multiple inputs with a space tabs between them if this possible , for example : i want to get the arrival time and execution time from user
arrival (spaces " ") execution >> i want the input be like this input1 (spaces " ") input2
I made a working version using absolute vextors being rotated by matrices and keeping relative vecotrs for translations. What I didnt like is that I HAVE TO use the standard XYZ axis for rotation.What I decided to do was use quanternions to store current rotation,cthen buffer rotations each time some were done and add it up.The way I see it, it should look somewhat like this:
(in the UpdateRotation part, plz dont mind any typos i make, this isnt the actual current code. Also on a small note I use dictionaries, so dont be surprised xD) Code: RelativeVectors["Up"] = Vector3.Transform(AbsoluteVectors["Up"], (Quanterion)CurrentRotation); //repeat for Look and Right relative vectors Quanternion Yaw = Quanternion.CreateFromAxisAngle(RelativeVectors["Up"], RotationBuffer["Yaw"]); //repeat for roll and pitch CurrentRotation = Quanternion.Contancate(CurrentRotation,(Yaw*Pitch*Roll)); //
clear the rotation buffer Whats happening right now tho, is that doing this exactly doesnt actually do anything, so I have to use standard axis anyway.
I am getting an error on lines 31 and 36 about an expected identifier on my program that computes area and circumference. Is something wrong with my external functions outside of main?
I am actually developing an nginx module in C.I am not to bad in C, but i got a big problem to pass argument to a vadiadic function.This function look like the well good old printf, but you put a buffer as first argument, the last address to stop to put data as second argument (in my case it is the last adress of disponible memory), a string that look like one in printf, an the other argument after.Here is the problem, the 4th last argument does not have the good value. In fact, It seem to be random value from memory. I Use gcc (Debian 4.9.1-19) 4.9.1.
This is part of a bigger program im working on that deals with data structures, but I'm trying to figure out a way to tokenize a long file of purchases that is being read to my program. I rewrote the program to pinpoint my problem. I need to get the name, cost, item and quantity from this string. I figured out how to look for the cost, but what about the name and item(shirts)? How can I do this all in one loop because there are multiple strings and i'm gonna eventually send all the info to a data structure for each person(name)? I'm only asking about the tokenizing part, but this code works for the cost.
Code:
int main(void) { char myString[] = "Angela bought 9 shirts for $6 each." ; char * del = " " ; char * token ;
I am attempting to break up a file into smaller chunks and have it process the different parts of the file in parallel to speed up the entire process. I was thinking maybe 4 chunks at a time. How do I get my program to do this? Is there a good book explaining parallel processing in C?
I have tried writing a code and come across an issue where I'm not getting the desired result. It is to design a program that tells whether gas emissions from a car are too high, or permissible. The instructions are to design a code where there are four possible choices of pollutant, whether the emitted pollutant ratio is greater or less then a certain value, and the mileage on the car. All of these are supposed to determine whether the emissions are permissible or not, which would be displayed with printf. (The actual conditions of the assignment are described perfectly by the code below, so I didn't think it would be necessary to write it out. The problem is that I'm getting a logical error.) Here's the code:
Code: #include <stdio.h> int main() { int poln, odr; double gpm; printf ("(1) Carbon Monoxide
[Code] ....
My error is that the program will proceed with the first four if/else statements, but once the 'poln' value changes to something other then one, it will not display the expected quotation.
For a program I am required to use a cin that accepts 4 variables. The first describes a function such as add(), remove(), print(), or quit(). The problem is that to use add() I need to input all 4 variables but for remove(), only 2 variable input is needed.
I want the input to be "add 9 James Bond" or be "remove 341"
Here is my current code.
int command(string command, int Id, string first, string last){ while (command != "quit"){ cout << "customers> "; cin >> command >> Id >> first >> last; if (command == "add")
So I have a rather large (for me) project, requiring me to have two .cpp files and a header. Anyway, both of the .cpp files #include the header file, but I recieve linker errors because the variables and functions in the header are declared and defined twice (once in each .cpp file). How am I supposed to do this?
I have an inherited class that essentially manages a Qt Window.
It is as follows (prototype below):
class QTMyOpenGLWindow : public QWindow, protected QOpenGLFunctions { Q_OBJECT
[Code] ....
Now, I can understand the confusion of the compiler, but the functionality as I laid it out works for me (I can create the class with just specifying the parent and also have the option of preventing auto-initialization when creating). But, is there a better approach?
I'm still having troubles connecting multiple clients to my server.To break down what I have going:I have a server that is supposed to accept multiple clients.. Currently, It works with one person.While the server is running, One person is allowed to play the game (While connected to the server). If the server is down, the player cannot play (This shows that the server and client responde and work).
However, While the server is running and the client joins, the first player is allowed to play. Everyone else's window goes black and says "Not Responding" (Like any other game in which isn't working).While these players are in "Not Responding", It still says the client has connected onto the server (But they're not able to play?).My client code is working perfectly, But i'm having troubles accepting multiple clients onto my server.
#include <iostream> #include <winsock2.h> #include <vector> #include <process.h> #include "Included/pthread.h" //Some things i'm using or will be using in the future
I am struggling with a project right now and I was wondering if there was a quick way to find multiple modes in a map. So far I have a function that returns a vector of one or many modes depending on the map. I can't seem to wrap my head around how to test it->second against other seconds to find the one that occurs most often.
I would like to return multiple values from one function to access in different functions. For example:
int function1(//what goes here?) { int a ; a = 1 + 2 ; int b ; b = 3 + 4 ;
return (what goes here if i want to return the value of a and/or b to use in another function?) ;
void function2() { //now i want to use the value of a here to use in an equation, how do i do that? //now i want to use the value of b here to use in an equation, how do i do that? }
I want to take multiple line string in c++. How can I take this.
Such as I want to take this as input:
HELLO MY LOVE, I M HAPPY BECAUSE SOON I WILL BE TO YOUR SIDE. THIS TIME WITHOUT YOU HAS BEEN ETERNAL. I INVITE YOU TO THE ZOO ONE TO SEE THE ZEBRAS AND GORILAS.
I found way around this, but I would like to know why it shows multiple declarations.
My solution is to declare this class in function body(void LoadLevel()), just before the throw statement. But why can't I define it inside my namespace, but outside function?
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.
