C/C++ :: How To Create A Txt File - Read / Write And Open For More Information
Jan 25, 2015How do i create a text file read and write in it but every time i reopen the program i must not override the data in the text file .
View 6 RepliesHow do i create a text file read and write in it but every time i reopen the program i must not override the data in the text file .
View 6 RepliesI am writing a program that models the ups & downs of a particular stock. Everything is pretty much done, except that I need to create another event to notify that saves the following information to a file when the stock's threshold is reached: date & time, stock name, initial value & current value. I have something like this so far:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
[Code]...
I feel like i need something along the lines of
s.stockEvent += new Delegate( ???? ) in my myFile class so it know when the threshold is reached, to write the information of the current stock to the file.
So I've been turning my programs into classes and I run into errors.
So this program is supposed to allow the user to open the file and either read or write to it.
I've omitted the read part from it as I want to attempt that on my own .
I get these compile errors:
fileclass.cpp:13: error: ISO C++ forbids declaration of ‘choice’ with no type
fileclass.cpp:21: error: ISO C++ forbids declaration of ‘choice’ with no type
fileclass.cpp: In member function ‘int file::choice()’:
[Code] .....
I have looked through te tutorials here, and even google it, as well as tried to follow the power points from my class..but I still can't seem to figure out how to make this code work correctly.. Basically I have to create a file called grade and write to it a student name and their grade score, and then read from the file all students names and there grade and display this on the screen as well as calculate the grade average for all of the students and display it.
Well I am able to write to the text file, but I can't seem to get the rest to work. I can't figure out how to read from the text file..Here is my code below.
write a sample code that does something similar write to text file string and numbers and then reads from it.
#include <iostream>
#include <fstream>
using namespace std;
[Code].....
The Objective Of This Program Is To Create A File To Write Text And Read Back The File Content. To Do That I Have Made Two Function writeFile() To Write And readFile() To Read.The readFile() function works just fine but writeFile() doesn't.
How writeFile() function Works? when writeFile() function Execute It Takes Characters User Type And When Hit Enter(ASC|| 10) It Ask "More?(Y/N)" That Means What User Want? Want To Go Next Line Or End Input?
If "Y" Than Inputs Are Taken From Next Line Else Input Ends.
But The Problem Is When Program Encounters ch==10 It Shows "More?(Y/N)" And Takes Input In cmd variable.If cmd=='Y' I Mean More From Next Line Than It Should Execute Scanf Again To Take ch I Mean User Input.But Its Not!!! Its Always Showing "More?(Y/N)" Again And Again Like A Loop.
Code:
#include <stdio.h>
void writeFile(void);
void readFile(void);
int main(){
[Code].....
#include <stdio.h>
#include <stdlib.h>
int main () {
FILE * pFile;
long lSize;
char * buffer;
size_t result;
pFile = fopen ( "myfile.bin" , "rb" );
[Code] .....
How to open binary for read and write? Why the buffer is char * buffer? i mean in binary u cant read chars . How can it be? how the data is represented? just like txt file? What the buffer will contain how to print this buffer???
When I write the Ctor as follows, I get an Error: Invalid Sharing Flag 0 (That happens when file exists or does not exist)
File::File(const string& file)
{
m_file.open(file, std::ios::out, std::ios::app);
}
When I write the Ctor as foolows, I manage to open / create a file.
File::File(const string& file)
{
m_file.open(file);
}
What is wrong with option #1?
note that m_file is a data member of type ofstream
Perhaps my original wording on this was confusing so I will ask a different way.
if I have a text file called
data.txt
and it has the following in it.
12345
67890
12345
67890
how would i read this information into an array called
int data[4][5]
This is in C.
I have a folder "pics" in g: drive. There I want to create some text.txt file. Thus, the final path is "g:pics ext.txt".
How can I do that?
I am using
string text = System.IO.File.ReadAllText(@"C:datainput.txt");
to open a file and save it content to "text"
How can I instead create new window where user will select the .txt file he wants to read like many applications do
This is a WPF application
I'm trying to write a program that opens a directory and for each file in directory,it creates a thread. Inside of the thread,it reads the numbers in file.(one number in one line)And then calculates the average of these numbers. I write something like this;
void *calculate(FILE *piece){
int a,k=0,s=0,ort;
while(!feof(ayri)) {
a=fgetc(ayri);
s=s+a;
[Code] ....
When I run the programme,i get lots of errors like 'segmentation error' and some stuff about pthread_create. And I don't think the 'calculate' function is right.I don't know the right way to read numbers line by line.
For my intro to c programming class, our homework requires us to read a data file and emit various bits of information. the data file looks like this
#Domain: the URL
#Alexa: some kind ranking, small numbers are better
#Rank: another sort of ranking, big numbers are better
#Domain Alexa Rank Site Name
#------------ ----- ------- ---------
amazon.com 13 1177136 Amazon.com
google.com 1 4533883 Google
youtube.com 3 3637788 YouTube
[Code] ....
I've started and am able to get the correct number of lines, and the alexa number, but I keep getting some errors and am just unsure where to correct my code. This is what it looks like;
Code:
// Lexi Anderson
//CS 156
#include <stdio.h>
int main() {
[Code] .....
and once compiled, I get errors.
So I have to read from a file, and store the information in separate variables. My problem is that for some of the information I need multiple words, and for others I don't, so I cant simply store 1 word into a variable and store the next in another in so on. To demonstrate what I mean let me give an example.
Dog Cat Blue Bird Snake White Horse
I am able to store "Dog","Cat","Blue","Bird"...etc in variables but I don't know how to make it so I can store "Dog" in one variable, "Cat" in a second variable. and "Blue Bird" in a third variable. "Snake" would be the 4th and "White Horse" would be the fifth. How can I read a file and manipulate the pointer to grab what I need?
Im trying to read and store several students information so that i can have an options menu where i can enter a student number and the program prints all the information stored about that student. The way i have it set up now, doesn't work for this because all info is reinitialized to stud1. Is there another way to store this info other than defining stud1, stud2,.....,stud200?
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
struct student_info {
char first[20];
char last[20];
[Code]....
how I can read information from a text file into an array so afterwards I can display the array and it will show the contents of the text file?
the information inside my text files consist of names and numbers like so: "Collins,Bills 80" should I separate the numbers and names into two separate text files one for names and one for numbers?
My code so far is this:
#include <iostream> //for cin and cout
#include <fstream> //for input/output files
#include <conio.h> //for getch
[Code]....
Reading a .dat file, i'm unable to open the file. This program is for a Air Quality index detector, the AQI machine records the particle concentration every minute and saves it into new data file for each day. So I need to make this program run every minute and convert the concentration in to the AQI readings.
The filename is of the format "ES642_2013-11-09.dat", where ES642 is the software name of the machine, and rest is the year, month and day. The code here is just for the file reading section:
Code:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
[Code] .....
I'm having trouble with how to find the count and sum of all numbers.
The file, called question1.txt, contains numbers:
1
2
3
4
5
0
0
0
-2
-2
Here's my code:
Code:
#include <stdio.h>
#include <stdlib.h>
int main (void)
{
FILE* spIn;
FILE* spOut; //for output file
int numIn;
[Code]...
I am in an "intro" C++ course and am having trouble with a section of my current project.
We are required to open a text file, read the data from that file, and print it back.
However, we are supposed to let the user input the name of the file that is to be opened. This is the code I have so far. It is not opening anything.
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
const int NUM_QUESTIONS = 30;
typedef char CharArray[NUM_QUESTIONS];
string fileName;
[Code]...
The objective: Open and read a CSV file one line at a time using SQL commands.
The problem: I am getting an error that I have a feeling may not point to the "real" problem.
Where I may have syntax or other errors in code.
stInputConn = "Provider=Microsoft.jet.OLEDB.4.0;Data Source=V:\IT\RE\Exports\;Extended Properties="text;HDR=YES;Format=Delimited(,)"";
OleDbConnection cn = new OleDbConnection(stInputConn);
stInputFileName = ConfigurationManager.AppSettings.Get("InputFile");
// the input file name is CSV_DataExport.CSV
[Code] .....
The last line (ExecuteReader) is where I get the OleDb Exception.
How can I erase the data stored in /tmp/a.txt after every run of this code?
Code:
#include <stdio.h> // IO operations
#include <unistd.h> //for pid, ppid, fork functions
#include <sys/types.h> //for pid_t type, kill function
#include <stdlib.h> //for exit function
#include <signal.h> //for kill function
#include <sys/types.h>
#include <sys/stat.h>
[Code]...
I have a .txt file which I want to read from and then write a new text file, this time with sorted lines. It is easy to sort one value, but what about sorting entire lines based on one value?
I want to sort the lines based on the FIRST value.
Example text file contents:
values;data
5.01 100
2.9 342
2.69 43534
10.1 43
6.8 45324
Output: Text file containing
2.69 43534
2.9 342
5.01 100
6.8 45324
10.1 43
It's easy to do this if there was only 1 number on each line, but I do I sort all the lines based on the first number in each line?
this is my read/write functions based the read from the last post! then went nuts with it! used the %19s%*s on the write to the file, solved all the probs on the read side! but any refining on this would be great. This is another program that i started with the forums, and started going my own direction!
Code:
void WriteAccount(int account,char *a[])
{
FILE *fptr;
char Memo[20];
char buff[20];
double Amount;
struct tm *sTm;
}
[code]....
the a[] is a string array with bank account names, and Account is the number on the menu based list.
I'm looking to write a program in C/C++ to traverse a Fasta file formatted like:
>ID and header information
SEQUENCE1
>ID and header information
SEQUENCE2
and so on
in order to find all unique sequences (check if subset of any other sequence) and write unique sequences (and all headers) to an output file.
My approach was:
Prep: Copy all sequences to an array/list at the beginning (more efficient way to do this?)
Grab header, append it to output file, compare sequence for that header to everything in the list/array. If unique, write it under the header, if not, go on.
However, I'm a little unsure as to how to approach reading the lines in properly. I need to read the top line for the header, and then "return?" to the next line to read the sequence. Sometimes the sequence spans more then two lines, so would I use > (from the example above) as a delimiter? If I use C++, I imagine I'd use iostreams to do the reading.
How to read some characters from file, I know we can move a pointer to some position using seekg() & seekp() function, get current position of the pointer through tellg() & tellp() functions. By moving the pointer to appropriate position using seekg(), we can read the whole line using getline() function. But is there any function which read certain characters from the current position of the pointer and write certain characters from current position of the pointer.
View 1 Replies View RelatedHow to read some characters from file, I know we can move a pointer to some position using seekg() & seekp() function, get current position of the pointer through tellg() & tellp() functions. By moving the pointer to appropriate position using seekg(), we can read the whole line using getline() function. But is there any function which read certain characters from the current position of the pointer and write certain characters from current position of the pointer.
View 3 Replies View Relatedthe output of the password text file contains like this:
username
776655443322 (password encoded)
How to write the value in last line (3rd row) of the file. after that read and write or alter 3rd row value. I need logic using "C" language.