My assignment was to take numbers from two different files, and merge them into a third file in numerical order. I have everything working well, but the output shows the lowest number everytime and i'm not sure why. logical error ....
How do I read a .pdf file using C++? When I try to open it using myfile.open ("example.pdf"); but all I see is some Crazy Symbols. Is there any way to open ?
It has something to do with the lines at the bottom of the code. It doesnt cout anything. The program just crashes upon execution. First, it asks me the amount of students i want to handle. I enter '1'. Then it asks me if i want to read in from external file and i enter 'Y'. then the exe just crashes
Name: Mary Smith Exam 1: 65 Exam 2: 79.1234 Exam 3: 70.24
Becomes something like this in the output file:
Name: Parker, Peter Average Score: 92.28 Grade: A
Name: Smith, Mary Average Score: 71.45 Grade: C
I know I'm supposed to read the whole file, but I'm getting really confused on how to take the name of each student separately without recording Exam 1, 2, and 3. I'll be able to do the average score and grade on my own.
Is there a way to indicate how many records exist in a given file? For example, vectors have the vector.size() command to show the number of given elements. Is there a such command for files and records?
The directions are to write a program that reads sorted integers from two separate files and merge the contents of the file to an output file (third file). The only standard output will be any errors to be reported and a “FINISHED” statement after all items have been processed.
file1.txt 2 4 6 8 10
file2.txt 1 5 11 12 15
Output.txt 1 2 4 5 6 8 10 11 12 15
This is the code I have so far, but it is not working, and I have put the two txt files in the same directory as my .cpp file. It is not working though still. What have I done wrong and how can I fix it to read these integers from the two numbers and merge the contents into a third file?
#include <iostream> #include <fstream> using namespace std; int main() { int num1; int num2; ifstream inputFile;
I'm messing around with reading and writing files. The first file creates a small txt file. Simple enough
#include <iostream> #include <fstream> #include <string> using namespace std; int main(){ string name; string desc;
[Code] ....
It does what it should. It creates a text file "items.txt" .... It reads as such:
dagger,a dagger,15,10,0,1,3,1,0,0,0,1,0,0,0,0,0,1
The second file is meant to read the file and place the data back into the variables. This happens, but the data crams itself into the first variable, and the rest of them collect the trash that's in memory.
#include <iostream> #include <fstream> #include <string> using namespace std; int main() { string name,desc;
[Code ....
I need to get "dagger" into name, "a dagger" into description, and each value with their perspective variable. I'm sure I need some type of "separator". Hopefully I can use the comma. Before it's over, I will have about a hundred items that will need to be read into a class of items.
struct magic { char windowsheader[2]; } magicnumbers; struct bmp { unsigned int sizeofthefile; short int applicationspecific1;
[Code] .....
When I run this program, seems like it is working,at least I am sure that it gives the right file size. But if I don't use struct magic and instead use:
Code: struct bmp { char windowsheader[2]; unsigned int sizeofthefile; short int applicationspecific1; short int applicationspecific2; //same lines with above } bitmap_header;
And if I don't use first fread:
Code:
fread(&magicnumbers,sizeof(magicnumbers),1,fp);
Then the values which structure "bmp"'s variables get become wrong. Of course I change the related printf to:
... so a very simple file format. and what i need to do is to read that into memory (vector of strings) so that header info and seq info is in two different vectors. for that i am using the following function :
this code does what is suppose to do but it is EXTREMELY slow. it takes me exponentially more time to read the seq in memory then to process it. when compared to c style alternative that reads character by character it takes 13 sec with this function to do the same job that my c function does in 0.03 sec. How to improve upon this function to make it comparably fast (also i am using optimization) ?
I want my program to be able to read text files in the format:
number number number number number number...
and so on, so there are two columns of values. The problem I'm having is, there are a lot of numbers in the file, and it can vary. The program needs to read the numbers, put one column into one array, and the other in another, perform some operations on it all, and eventually pop out two different arrays. In other words, after I've got these arrays, I don't need them for much longer. I was hoping I could dynamically allocated some arrays to store the numbers and just free them as soon as I'm done with them.
If the file wasn't of such variable size or if it was guaranteed to be under a certain number of variables, I would have used:
program that I am working on. I want to use fgets() in my program so I could handle multiple words from a text(to be able to handle spaces). I get a weird result when running the program.
How to write the code for this with the following requirements:
download the text file weblog.txt
This file is an Apache web log taken from the web server for St. Mary's University. When a visitor goes to their web site, the visitor's browser makes a request to the web server to view a web page, which is a file residing on the server. Each time a page is requested by a browser, the web server records information about that request. This weblog.txt holds the details of some of those requests.
Create a non-member function to read each line of the web log file. This function must do error checking to ensure that the file is opened successfully, otherwise it must provide a message like "file not available" to the user.
Each line should then be stored in a vector such that the first element of the vector is the first line of the web log file. Because each element will hold an entire line from the file, the vector should be declared as a vector of strings.
Note: You must declare the vector in a function.
Create another non-member function to sort the contents of the vector. Make sure to pass the vector by reference or your sort will disappear when the function ends! Use the sort function with #include <algorithm> to do the sort; you do not have to write your own sort algorithm.
Create one more non-member function to write the contents of the vector to a file. Each element should be on its own line in the new file. The contents of the new file should look like the original input file once your program completes, but in sorted order.
Create a main function that calls all of your non-member functions.
why I'm giving "Access violation reading location 0x336827B8" and also I was able to read my data but it's giving me weird stuff. I want to write the sorted grades and the average in a new disk file. so here's my code so far here's my code
#include "stdafx.h" #include <iostream> #include <fstream> #include <string> #include <iomanip> using namespace std; int avg(int sum, int size); void swap(int *, int *);
I have a problem to read a large number of binary files, process them and store them under a new name. The program and routines go very well for 505 files. After reading 506 files, the program now refuses to read the next file. I have 16 Gb of memory and tried to close all other programs and restart the PC. it always stops after 506 files (512 files would be more understanding in a way...).
Here is my code. I have tried many things without success. This is only part of the loop that stops. The if test if (myfile.is_open() returns false by some reason. I can start the process again starting with the file that does not open and then it stops again after 506 files.
char * tfiBlock; ifstream myfile (OrigFilename, ios::in|ios::binary|ios::ate); if (myfile.is_open()) { int lengde = myfile.tellg(); tfiBlock = new char [lengde]; //static char memblock [size];
[Code] .....
Clean up procedure: delete[] tfiBlock;
Are there any limits to how many files that can be opened, or is it maybe someting to be set in the compiler?
I know it sounds strange but I've seen things that have files which contain source code (usually in something in Python or such) and how this is read on run-time?
I am using the code below to write a single instance of object "Employee" to a file in Binary mode. The write part seems to work fine, however when I try to read the single employee object from the file into memory I get a double free or corruption error.
I think this has to do with the fact that I am using a string data member in the Employee class but I don't understand what is going wrong. I have read that strings can vary in length and use dynamic memory allocation but if I write a single employee object to a file with data member 'name' equal to "John", it should be the exact same size when I read it back in right?
The code below works with no issues when I omit the string data member. Why is that? Where is the memory for the string object being "double released" when I read the employee object back into memory from the file?
I am using Linux Mint 15, Eclipse June and GCC 4.7.3 with the -std=c++11 option.
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;
I'm trying to read stream data from a stream in a pdf file compressed in LZW. My first step is to read this compressed data into a buffer. The second step is to decompress it. I know how to decompress it, it is the first step I am having trouble with.
How should I read this data? If I read each character into a char the numerical output will not exceed 256. LZW compressed output should exceed 256.
I read the pdf in binary mode and have tried the read function like below.
From what I understand (don't quote me), I should be reading in 12 bits at a time. Is that correct and if so should I be using a bitfield. If I do need a bitfield then how to I read the data from the stream into a bitfield of 12 bits without restricting the binary value of the characters being read from the compressed stream.
Code: ifstream inputfilestream; inputfilestream.open("myfile.pdf", ios::out | ios::binary); char mychar; //unsigned char gives an error though it can be //converted to unsigned char later. while (inputfilestream.read(mychar, 1)) { // do something with the char.. I have stored it in an int vector }
I'm writing a code obfuscator in C. Debugger shows no errors in the code, but the program crashes after compiling -- I'm guessing it has something to do with while loops or reading data from files.
Code: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> // list off all replaced elements typedef struct ReplaceList { char *from;// from string char *to;// to string (random)
When i try to read it back from fstream again there are some symbols (binary obviously). How can i get my values back? I want to read those symbols and in a way to convert them to my old width and height values.
I have got an assignment. It is about comparing two files one file has sentences and the other abbreviations. so far i have managed to compare the abbreviations which appear in the sentence and erase punctuation linked to abbreviations.
However I am currently stuck on putting the punctuation back in when outputting the file. I am also stuck with replacing matching words in the sentences with the expanded abbreviations. Not sure which code to show. but sentences and abbreviations are below.
ABBREVIATIONS
Aberd Aberdeen admin administration approx approximate Austral Australia div division Capt Captain Comdr Commander e east HQ Head Quarters m metres mil million mt Mount n north NATO North Atlantic Treaty Organisation NSW New South Wales pop population s south sq square w west
Text file
NATO troops were on exercise in Aberd Capt Jones of the first div told Comdr Frank that his troops were near the E flank of the NATO forces. Complaining about the amount of Admin, Capt Jones radioed the NATO HQ asked for navigation relative to the HQ. The Captain then left.
For example the abbreviation "Aberd" in the sentence above needs to be replaced with Aberdeen from the abbreviations file. I need the last part of the abbreviation not "Aberd Aberdeen" need just "Aberdeen". Hope the info is understandable.
