C++ :: Reading Input - Reaching End Of File Too Early

Apr 24, 2014

I'm reading input from a file using an ifstream. The program doesn't seem to read any characters but continually returns eof no matter what file I use. Even when I do ifstream.open(filename) nothing changes. This program is intended to be the lexical analyzer of a compiler, so symbols are returned to indicate what kind of input is in the file.

Here's the code:

#include "lex.h"
#include <cstlib>
#include <iostream>
#include <fstream>
//other functions
char Lex::getChar(){
ifstream input;

[Code] ....

I'm sure I messed up the initialization of the ifstream somehow.

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C++ :: Reading Input File Into Value

Feb 16, 2014

I am trying to read from my input file Transactions.data which is set up as follows

V 250190
A 250190 2008 4 8788.00 0.00 000
and so on and so forth.

I am trying to read my V then go to switch (decision) to choose my case and preform further functions. My problem is that i cannot get past the first line so if it was

V 213400
V 123456

My code is supposed to check that the ID (213400) is valid then go on to the next line but it wont do that and prints out the first ID 6 times. My code is as follows:

char descision;
ifstream input;
input.open("Transaction.data");
if (input.fail()) {cout << "File could not be opened." << endl;}
input >> decision;

[Code] ....

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C :: Reading Input Without Using Arrays - File I/O

Sep 23, 2013

I am having trouble with file I/O.

Let say I have an input file like this

x1 y2 b4
85 z4 x2

I'm trying to read the input without using arrays. I would use fscanf(*arguments*) to get the first char, which is x. Then I call it again to get the second one, which is 1. Now I would need to get the second input, y2. How do I skip the white space character to get to char y ? And is it an effective way to get all inputs though ? (each input, example x1, is read into a function).

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C/C++ :: Reading Input From A File And Then Storing It Into Array?

Feb 16, 2015

I need to read input from a file , which contains multiple sentences of varying lengths. After each new line char, i need to store that sentence into an array.

#include <iostream>
#include <cstring>
#include <fstream>
#include <cstdlib>

[Code].....

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Visual C++ :: Reading Records From Input File And Do Some Statistics

Oct 1, 2014

The program will prompt the user to enter a every student's first and last name, major ( of 4 choices CMPS MATH PHYSICS or EECE ), and grade. it's agreed that the professor will enter the name NoMore to stop the entry.

the program willl then store the info in a txt file. after closing the input file, the program will open it again read the records one at a time until end of file, and do some statistics including: highest grade, average grade, and highest average by major.

Finally the program will print the results....

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C++ :: Reaching Array From Other Function?

Nov 17, 2013

I have to make an array in one function (NOT MAIN!!!) that does not return the array, but just the average value of its elements to main.

Then, I have to use elements from the same array to calculate other values form them (can also be in main).

How can I reach array from function f (not main) if the function f is not returning array?

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C++ :: Vector Reaching Its Maximum Size

Feb 5, 2014

My program enters the size of the vector from the user and then creates a vector of vectors (lets say SIZE1). In addition the user enters the number of vector of vectors he needs (lets say SIZE2) as follows:

class Vectors {
// member functions goes here
private
vector<vector<int>> vectors;
vector<int>::iterator it;

[Code] .....

With a few calculations and insertions to my vector (vector of vectors)... the program works fine and gives me the results...

However, with huge calculations and insertions the program stops working and gives me this message

"Unhandled exception at at 0x770DC41F in Test.exe: Microsoft C++ exception:std:bad_alloc at memory location 0x001CEADC"

Thus, it seems that the vector reached it's maximum size... I tried to use reserve() but did not work

I read that "By default, when you run a 64-bit managed application on a 64-bit Windows operating system, you can create an object of no more than 2 gigabytes (GB). However, in the .NET Framework 4.5, you can increase this limit"

What do you think would be the best option for me to do (note my program is very long and complex)(I'm currently using Microsoft Visual Studio 2012 32Win application):

1. convert my program to the .NET Framework (C++)

2. convert my program to C# in case c#

3. do any settings on my computer (my workstation has a 3.6GHZ xion processor with 32RAM

4. convert to another version of C++ that does not have any restriction on the size of the array (if available)

Please note that I never worked neither with the .NET framework nor C#

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C++ :: Reaching Data Of Different Array Using Pointer In Loop

Jul 31, 2013

I have 3 arrays named: abee1 , abee2, myarray.

I have loop that want to call abee1 , abee2 one each time and copy myarray into it . It means that I reach the name of abee1 to abee2 in the loop for doing this. I made the name of each one by using strings ( abee1 , abee2) in the loop. In the last I want to copy the myarray into the abee1/2 using pointer.

I do not know what to do after the line "string arrayname = "abee" + String;".

#include<iostream>
#include<string>
#include <sstream>
using namespace std ;
int abee1 [4] [4] ;

[Code] ...

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C/C++ :: Writing And Reading From Standard Input

Mar 18, 2015

I have an HTTP/1.0 webserver that I'm building in C that needs to exhibit CGI script functionality. Specifically, what I'm having trouble with is that I have two processes: process 1 is the webserver, process 2 is the CGI script. I fork in the webserver, and then call exec to run the CGI script (specifically, I used execv()). I've read from the CGI specifications in the RFC that in the case of a webserver receiving a POST request, the CGI script should read the arguments for the POST request from stdin. However, when I write to stdin, it simply echoes what was written to the terminal window and when the CGI script tries to read from stdin, it blocks.

So, with all that said, I'm pretty sure there is some simple conceptual explanation to my problem, but I can't figure it out. Do I need to use pipes or some form of interprocess communication to send the data from the webserver to the CGI script, or can it just be done with stdin (and possible stdout)?

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C++ :: Reading Different Types Of Input Into Array

Jun 30, 2012

Let's say I have a list of words that are followed by a number.

Word 1
Word 2
Word 3
Word 4

I need two arrays. One for the words and one for the numbers.

Code:
string STORE_ARRAY[100];// stores string (word)
string operation[STORE_ARRAY];
int PARA_ARRAY[50];//stores parameter (#)
int parameter[PARA_ARRRAY];

For the file input, I'm using this:

Code:
in.is_open()){
string line;
while(getstring filename;
cin>>filename;
vector<string> file_input;

[Code] ....

So first it gets saved in file_input, but then it needs to split it and move it into the appropriate array.

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C :: Reading Button Input On Arduino Board

Mar 7, 2013

Okay so this is part of a small uni module around the arduino board. The task is to simulate traffic lights at a junction. At the moment my code below runs through the sequence with 2 seperate lights. When one set of lights turns RED , the other turns GREEN.In my main loop method I need to add a button for a crossing. I want to be able to check if the button is pressed at each of the delays but do not want to have to hold it down.I have thought about putting it at the top of the loop but then the program will only check if button is pressed in that point therefore the user will have to hold it down?

Code:

int green1 = 13 ;
int amber1 = 12 ;
int red1 = 11 ;

int green2 = 6 ;
int amber2 = 7 ;
int red2 = 8 ;
}

[code]....

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C++ :: Reading Input From Multiple Keyboards And Mice

Apr 28, 2014

I wanted to know if there was a way to separate the inputs received if there were a few keyboards and mice hooked up to a desktop/laptop.

Would there be a particular class that would best be utilized to do this?

I read that MouseEventArgs is one class that can recognize events, but I'm not sure if its best for what I need.

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C++ :: Opening And Reading Files With Input / Output?

Oct 15, 2014

I'm in a CIS 143 class which is Introduction to Programming using C++. We've been assigned a lab with little to no detail on how to do the things listed.

The purpose of this lab is to practice the file input and output concepts. For this lab you may assume that the input files exist and contain appropriate data inside of them.

Four separate text files* which contain the following lines, different for each file.

(*: This isn't on the lab, but don't worry about what the name, age, id, and major are. those can be random and I can just change them what they need to be)

Name
Age
Student ID Number
Major

Your program should ask the user which of the four input files they would like to open, and then read the contents from the file. Once the contents have been read in, it should output to both the screen and a file named "output.txt" the four values were read in, arranged as follows:

"Hello <name>! You are a <age> years old <major> student, and your ID number is <ID number>"

Now I am by no means saying "Do it for me". I just need to know how to have a user type file1, file2, file3, or file4, and then have the program open that file, then have the output.txt file arrange the wording into the sentence above.

This is what I have so far and I don't think it is anywhere near correct:

#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
ifstream inFile;
string file1;
string file2;

[code]....

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C++ :: Reading Specific Input Syntax - String Parsing

Apr 21, 2013

I need reading a specific input syntax.

something like

<Input> :: R C <Content>

3
3

.3. .15 9.2
.1. ..6 ...
6.5 7.. ...

... .5. ..9
4.7 .8. 1.6
9.. .6. ...

... ..1 7.4
... 6.. .9.
5.1 49. .3.

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C :: Make Array Stop Reading From Input When It Hits A New Line?

Nov 25, 2013

I want the numbers to be put into the array until it hits a new line. Maximum number of numbers is 1000. What can I replace that while loop with to stop it from reading further into the input file?

Code:

while (input != '
'){
for(i=0; i<1000; i++)
fscanf(ifp, "%lf", &auctions_prices[i]);

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C :: Reading From A File And Skipping Lines To Find String In File

Nov 26, 2013

Program background: Ticket Sales Details You will sell tickets in advance and at the door. Prices for buying in advance and at the door will be given. Also, the total number of tickets sold in advance will be given. Each guest will have a unique number. If there are n tickets sold in advance, then these guests will be numbered 0 through n-1. As the event starts, requests to buy tickets at the door may be made and these guests will be numbered sequentially, starting at the lowest unassigned number. The maximum number of guests will be 1000. The first line of the file contains the following three values, separated by spaces: Cost of the presales tickets (in dollars), Cost of the tickets at the door (in dollars), and the number of presale tickets. The first two values will be positive real numbers to two decimal places and the last will be a positive integer.

The second line of the file will contain one positive integer representing the number of auction items followed by a positive real value to two decimal places (at most) representing the minimum bid increment, in dollars. The first value is guaranteed to be 1000 or less and the second will be in between 1 and 50, inclusive.

The third line of the file will contain all the prices of the auction items, in dollars, separated by spaces, in order. Thus, the first price is the price of item 0, the next price is the price of item 1, and so on. These values will be real numbers represented to up to 2 decimal places.

The fourth line of the file will contain the three following positive integers pertaining to the raffle: the number of raffle tickets available, the cost of a raffle ticket in dollars, and the number of raffle prizes. (It's strange to have raffle tickets that don't cost a whole number of dollars.)

The fifth line of the file will contain each of the values of the raffle items, in dollars, separated by spaces, in order. Thus, the first price is the price if item 0, the next price is the price of item 1, and so on. These values will be real numbers with upto 2 decimal places.

The sixth line of the file will contain ten positive integers representing the number of each of the drinks 0 through 9, in order, that are in stock.

The seventh line of the file will contain ten positive real numbers with upto 2 decimal places representing the price of each of the drinks 0 through 9, in order.

The eighth line of the file will contain a single positive integer, numEvents, representing the number of events that occur at the charity ball. These events are split into two groups: actions by guests at the ball and awards given (raffle, auction, person, totalrevenue). All of the actions precede all of the awards. You will produce exactly one line of output for each event described. Here are the formats of each event that could occur:

If a patron buys a ticket at the door, a command will be on a line by itself:

BUY TICKET k

where k is a positive integer indicating the number of tickets bought at the door. These guests will be numbered as previously mentioned. You are guaranteed that the total number of tickets bought, including presales, will not exceed 1000. This is what I have so far and I cannot figure out why it wont calculate the total revenue. I am not completely sure if it is even accessing the if statement in main.

Code:

#include <stdio.h> #include <stdlib.h>
#include <string.h>
#define N 1000

[Code].....

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C++ :: Reading File Then Printing Data Onto Other File

Nov 7, 2014

I am reading a file then printing the data onto the other file. It is working, however when I check to see if each variable is being properly set after reading the file a issue arises.

Example of the file being read

Code:
Vehicle PV50CAN passed camera 1 at 05:33:26.
Vehicle W867BRO passed camera 1 at 05:33:29.
Vehicle KQ63ARU passed camera 1 at 05:33:38.
Vehicle K954ITQ passed camera 1 at 05:33:40.
Vehicle V220MXB passed camera 1 at 05:33:42.

[Code] .....

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C++ :: Multiple Of CSV File Used As Input / Extracting Data To A Output File - Getline Function

Jun 4, 2013

I have written a C++ program I have multiple of CSV file used as input, which I open one at a time and close it after extracting data to a output file which is the only file.

I run getline(inFile,line);
outFile << line << endl;

I run this code, and only part of it is goes to the output file I got, also have spacing randomly to specific file and inconsistent

But when I slower the code, like system("Pause") in the loop, I can get extract what I want perfectly....

Is my program running to fast, why getline would be skipping part of what things I want?

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C :: Program To Calculate Students Grades From Input File And Write To Output File

Aug 29, 2014

One of my class assignments is to create a program that receive a .txt file containing a students name and their grades as follows:

John K. 99, 87, 57, 89, 90, 95
Amanda B. Jones 100, 88, 76, 99, 86, 92
etc..

The number of students is unknown until run time. You have to take those grades and average them weighing the first (4) at 10% a piece and the last (2) at 30% each.

Then return an output file with the students name and their letter grade A,B,C,D,F based on their computed score. In addition, on screen it needs to display the average scores for each Q1, Q2, etc. as well as the minimum and maximum for each test on the screen. I am having a hard time in assigning the scores to a variable so that they can then be computed as an average and then used to determine a letter grade. I have begun to write the code and am a bit stuck..here's what I have so far:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

[Code]....

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C/C++ :: File I/O - Reading Values From File

Jan 28, 2014

I am trying to write a program that will open a file with 2 points, take those points, determine what quadrant those points are in, and save the result back into the same file without truncating the data.

I'm having some trouble with my file I/O. I can't get my program to read the two values for X and Y that I put in the points.txt file. It simply uses whatever random number was used last time in that block of memory. In my points.txt file I put something like "4 -5" and it wont assign those numbers to my X and Y variables. I believe the issue is on line 25

#include <iostream>
#include <fstream>
using namespace std ;
int main() {
//defining X and Y
double X, Y ;

[Code] ....

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C :: Computing Grades From Input File And Writing To Output File

Aug 31, 2014

One of my class assignments is to create a program that receive a .txt file containing a students name and their grades as follows: John K. 99, 87, 57, 89, 90, 95 Amanda B. Jones 100, 88, 76, 99, 86, 92 etc.. The number of students is unknown until run time. You have to take those grades and average them weighing the first (4) at 10% a piece and the next (2) at 15% each and the final at 30%. Then return an output file with the students name and their letter grade A,B,C,D,F based on their computed score. In addition, on screen it needs to display the average scores for each Q1, Q2, etc. as well as the minimum and maximum for each test on the screen. I am having a hard time in assigning the scores to a variable so that they can then be computed as an average and then used to determine a letter grade. I have begun to write the code and am a bit stuck..here's what I have so far:

Code:
//
// main.c
// Final Exam
//

[Code].....

The problem I'm having now is how to go about passing the grades to the function computeGrade and then compute the average and return that to the function.

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C++ :: Decompress Input File And Write Results Into Output File?

Jul 8, 2013

how do i decompress an input file and write the results into an output file?

also my do while loop is supposed to keep going unless the user selects the option to exit the program, instead it exits after finishing ay of the options.

here's my code so far...

#include <iostream>
#include <iomanip>
#include <fstream>

[Code]....

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C++ :: Reading From A TXT File?

Jan 5, 2014

If I am reading data from a .txt file with a person's last name and first name (e.g. Miller Andrew), How do I output the same data with the first name followed by the last ?(e.g. Andrew Miller) Do I use the ignore function?

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C++ :: Reading PGM File From HDD

Aug 30, 2014

I want to know how to read a .pgm file from my hdd and store it in a 2d array so i can perform some action on the array later on. This is ny first time working with an imqge in c so i know nothing about it. .

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C/C++ :: Reading ID3 Tag From MP3 File

May 25, 2014

I have been given a task to make a c++ program that promptsd the user to enter a mp3 file name, read the ID3v1.1 tag and displays it. It then should prompt the user to to decide if they want to edit the comments section of it, then if they edit the section, it should re-print the updated ID3 tag. The list of genres are in a cstring that is as follows.

char genre[126][128] =
{
"Blues" "Classic Rock", "Country", "Dance", "Disco", "Funk",
"Grunge", "Hip-Hop", "Jazz", "Metal", "New Age", "Oldies", "Other",
"Pop", "R&B", "Rap", "Raggae", "Rock", "Techno", "Industrial",
"Alternative", "Ska", "Death Metal", "Pranks", "Soundtrack",

[Code] .....

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C/C++ :: Reading From TXT File - Last Value Appear Twice

Aug 22, 2012

Using the feof() function in the output file i have the last value twice.

This is the input:
1 3 6
1 1 4
0 3 1
1 1 6
0 6 2
1 1 6

And the output should be:
12
6
15
13

But using the feof() the last value appears twice:
12
6
15
13
13

How can i change that?

while(!feof(pfile1))  {  
        sum=0;
        fscanf(pfile1,"%d%d%d",&choice,&day,&val);
        if(choice==0)

[Code] ....

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