C :: Return Errno From Open Function And Print It To Screen
Mar 22, 2013
i am programming Cli/Ser ,so part of the program is to open file to download it from client side,but i want to return the global value Errorno to print it to screen , and how to use strerror() func ??? i write this "This is part of server code" :
Code:
fd= open("abc.txt",O_RDONLY);
//error handilng in open file
if(fd<0)
{
This seems simple enough but I'm missing something here to make this code work.What I'm trying to do is print the contents of the two dimensional array in 25 rows and 4 columns. I experimented with something similar to this code when I initialized the array with numbers.
I'm getting garbage. I tried including the name of the array in the cin object but I got an error message that says "no match for operator '>>'. When I take the name of the array out, the program compiles but I get garbage. Program is suppose to reads data from a file of 25 students and calculates test scores and class grade average output each student's name score, letter grade and grade average. I would be happy at this point if I could just print out something that wasn't garbage.
Here is the code.
#include <iostream> #include <iomanip> #include <cmath> #include <string> #include <fstream> using namespace std; //const const int Array_Row = 25; const int Array_Col = 4;
i need to return a struct pointer dynamically allocated inside a function call void function() which is done using 'out parameters' in following code
struct my_struct { int x; } void my_function( my_struct** result ) { my_struct* x = new my_struct{ 10 }; //... *result = x; }
Now i have a doubt, so if i want to print the return value from struct pointer, should i need to print it in the void function() or in the caller the function...
I dont know how return message when user fail to open Database.
I building this class to manage db
The "open" method return an OleDbConnection type to manage it later
On catch zone I cant return string , int or other types
class ApriDB { //Stato interno string connessione = ""; // metodi public ApriDB() { } // Costruttore di default public OleDbConnection open (string connessione) { OleDbConnection conn = new OleDbConnection(connessione);
Numbers are 3d6 Rolling die no.1... RolledDie: 4 DieTotal: 4 Rolling die no.2... RolledDie: 5 DieTotal: 9 Rolling die no.3... RolledDie: 5 DieTotal: 14
How to print to the screen the value of n after it has been multiplied.
For example: if I use cout << "n: " << n << " power: " << power << " "; I
can see the variable "power" decrementing by 1, but I don't see the variable "n" incrementing with its new value after it has been multiplied by n * n.
#include <iostream> using namespace std; typedef unsigned short int USHORT; typedef unsigned long int ULONG;
fstream infile1(argv[1]); if(!infile1.is_open()) cout << "Could not open file"; else { char listNum; while(infile1.get(listNum)) cout << listNum; }
However, when I check for odd or even numbers it will check each and every number.
printed like this (partial list): 1 is odd 3 is odd 8 is even 9 is odd
But it should print: 138 is even 9 is odd
I tried using getline, but it keeps giving me the errors: invalid conversion from 'void*' to 'char**' invalid conversion from 'char' to 'size_t*' too few arguments to function 'ssize_t getline(char**, size_t*, FILE*)'
Here is the getline code, what am I doing wrong? I have tried switching things around, adding things. Just nothing works.
ifstream infile1(argv[1]); if(!infile1.is_open()) cout << "Could not open file"; else { char listNum; getline(infile1, listNum); cout << listNum; }
Given this sentence as an input: "Hello my name and "John" (with its spaces and capital letters), print it on the screen .. NB the phrase must be entered from the keyboard all at once ... you can do this in C / C + +?
I'm trying to write a program that prints all of the prime numbers to the screen. I'm getting angry because it only prints EVERY number. I think it has something to do with the bool change not being able to leave the for-loop but how to fix it.
Code: #import <stdio.h> #include <stdbool.h> int main(void){ printf(" The Primes Are: 1");
I have a text file where in each line is 3 words and 2 int type numbers. I'm doing search by word and I want to print out to the screen the whole line where that word was found (the words is repeated in some lines). My search looks like this:
Code: #include<iostream> #include<string> #include<fstream> #include<stdlib.h> #include <vector> using namespace std; int main(){ vector <string> words; string str, paieska;
I am trying to automatically(periodically) print screen a custom area of the screen, save it as an image file (the image will have the same format always), and then use OCR to get the text in the image as usable string variables. Is this doable? I was looking into tesseract OCR but I find it a bit unclear.
I am trying to make a program that will convert a list of binary numbers from a file into decimal and print the decimal to the screen. I have no problem doing the conversion, the problem comes up when our teacher wants the input file in a format as such:
3 10110101 11111111 10101010
The first number is supposed to tell the program how many different 8bit strings it is going to have to convert, and then the following lines are those binary numbers.
I am not very experienced with file inputs, and I know how to open files and read lines in.. The problem is, how to say "ok the first line says 3, so now I have to convert the next 3 lines" . I am assuming it is just a simple loop that I am missing....
Basically this is what i need to do. Write a program that reads a number from the keyboard, separates it into its individual digits and prints the digits to screen, each on its own line followed by the same number of stars as itself.
For example, if the number is 2339 the program should print
9 ********* 3 *** 3 *** 2 **
So far i have managed to separate the number and have them on different lines, but how to implement the stars onto each line with the number!
My code so far:
int main() { int n; printf("number? "); scanf("%d", &n); while (n > 0) { printf(" %d
I'm writing some functions pertaining to binary trees. I've used recursion once before while learning quicksort but am still quite new and unfamiliar with it. And this is my first time touching a binary tree. So my question: In my addnode function, will the return root statement at the end ever return a value other than the value passed to the function?
I am trying to open a file and print the contents of the file to the terminal window. It works when I put the file right in the directory with the Solution but not if the file is out on my desktop and I use the full path. Here is the code:
#include <iostream> #include <fstream> #include <string> using namespace std; int OpenFile(){ fstream SampleFile;
I am using C++ to write data into a (.ini)file. However, when I try to print the value '0A' I am getting '0D 0A'. (this is what I see when I copy the output to HexEdit). From what I can figure out, '0A' is the ascii for 'new line' so write function automatically adds the '0D' which is 'carriage return'. What I want is to print 0A alone. how can I do this?
Note: Windows it is working fine, but linux it is not working...
unsigned char arrRes[4]; int N = 10; memcpy(arrRes,&N,4); std::ofstream Output(LUT_OUTPUT_FILE_BINARY,std::ios_base::binary | std::ios_base::out); Output.write((const char*)arrRes, 4);