I have a file blah.txt like this:
3 1 4
1 2 3
and here is my code to read in that file:
Code:
int x = 0, y = 0, z = 0;
ifstream data("blah.txt");
while(x != 1)
{
data >> x >> y >> z;
}
For some reason, it just keeps readin in the values: 3 1 4
I want to access specific lines in a "*.txt" file. I've heard of seekp() and what not, but don't know how to call them as such.
View 6 Replies View RelatedI am trying to read a file line by line and then do something with the informations, so my method looks like this:
Code:
void open_file(char *link) {
FILE *file = fopen(link, "r");
if (file == NULL) {
fprintf(stderr, "Could not open file.
");
exit(EXIT_FAILURE);
[Code] ....
1) The first complain of valgrind is at the line where I use fgets and its telling me (invalid write of size x), but I have allocated my line to 56000 and the read line is shorter, why is there a write size error then :S?
2) at the line where I realloc where I try to shrink the space he's telling me: Address .... is 0 bytes inside a block of size 56000, But I know i need only this space so why is there a write over space error :S??
So I'm reading a file line by line and storing it backwards into a list. So if the file has has this format...
1
2
3
4
The code should store each line in a list as such...
4, 3, 2 ,1
Instead the code will store the last variable in all nodes. So the final list will look like this...
4, 4, 4, 4
Here is my code...
struct node *head = NULL;
int i;
while(read(in, &i, sizeof(int)) != 0) {
struct node *temp = malloc(sizeof(*temp));
temp->line = &i;
temp->next = head;
head = temp;
}
Im trying to read from a file, line by line, with no specified number of values in the file. Check out my code:
int main() {
string x;
ifstream fin;
int count = 0;
char ch;
fin.open("CWC_Master.txt");
if(!fin)
[Code] .....
Now, this works great! However, its skipping some lines. And I dont know why. For example: Lets say that the input file is:
superman toy
sm2335
19.99
batman toy
bm5532
25.99
aquaman toy
am6786
26.00
Where it should output the above, instead it outputs every other one. Like:
superman toy
19.99
batman toy
25.99
aquaman toy
26.00
How can I fix my code so that it SIMPLY(i say simply because I am still a beginner coder) can read line by line?
I have to read the information about logic gates from a file. The file format is shown below:
Code:
gateOne = NAND(inpA, inpB)
gate2=NAND(1,2)
3 = NAND(23,25,26)
As, it can be seen from the above structure that whitespaces are not same everytime. So, to deal with this situation, i am using boost library to remove all whitespaces from the line which is being read and then try to find the name of gate and its input. My code is given below which is able to correctly find the gate names and its first input...but my code is not able to find the second, third and so on input names.
Code:
//C
#include <stdio.h>
//C++
#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <cstring>
#include <boost/algorithm/string/erase.hpp>
[Code] ....
How to read a file line by line and then later access them by doing something like
Code:
lines[0] //Line number one
...
lines[100] //Line number one hundred and one
lines[100][0] //L
lines[100][1] //i
lines[100][2] //n
lines[100][3] //e
lines[100][4] //
lines[100][5] //n
...
First of all I need to know how to read from file.
Second, I need to read line by line from the file.
For example, the file contains:
8H 3S TH 9D 5S
5D KD 9H 4D 3D
8C TD 5D QS 2C
I wanna use array, so I need to store 8H in array[0], 3S in array[1], until 5S get stored in array[4].
I need to read the first line, the the second, and then the third.
how do i implement codes where it shall prompt for an user id.
From the input,the system shall look into the file..and output if the data exist.
For example in the file,
A123
Robinson
012345
B345
Crusoe
543210
So,i juz wanna input for B345.
Output shall be:
B345
Crusoe
543210
The code below is reading the whole data in the file but I only want to read one.
#include<iostream>
#include<fstream>
#include<iomanip>
#include<string>
using namespace std;
int main() {
fstream inFile;
[code]....
how to read the next line in the file. I think I need to use a for loop, but not sure how to implement it.Lets say my input.txt file has three names:
Sally
Tom
Sugar
I can get Sally, but not tom as yet. fgets also gets me to the same place.
Code:
int main(){
char str_1;
FILE * ifp = fopen("input.txt", "r");
fscanf(ifp, "%s", &str_1);
printf("%s", &str_1);
return 0;
}
void login() {
//username, password, option to register, option to exit, link to website
cout << "Would you like to login(1), or press anything else to register.?" << endl;
cin >> loginYorN;
if (loginYorN == 1) {
cout << "Please enter your username: ";
cin >> accountInfo[1];
[code]...
So as above, I ask them to input 1 for login, anything else for register. Whatever they input, it get's stored into loginYorN, then I check to see what they input. If they put '1' for input, then I ask them for their username, store that into accountInfo[1], and then asking for the password, storing that into accountInfo[2].
Now here is where I need to input line 1(username) from login.csv or login.txt and line2(password) and storage these into accountID and accountPW.
I had a problem which i fixed it but couldn't fix it in a nice way. Lets understand my problem first, i have a file and has data in the following format
Id(int) and Description(string)
Code:
1 this is first line
1 continuity of first line
1 again first line
2 this is second line
3 this is 3rd line
3 continuity of 3rd line
3 again 3rd line
3 and again
4 fourth line
I was only interested in the integer part and ignore the description at first, it was easy because they are separated by a tab.
Here is my code for that problem
Code:
#include<iostream>
#include<fstream>
#include<string>
#include<cstdlib>
#include<limits>
using namespace std;
int main(){
string str;
[Code] .....
But now i need that description again which i ignored at first means the rest of the line, so how to get it? so is there any way of solving it? Here is my approach but i can't find any method to access to the rest of line
Code:
value = atoi(str.c_str());
(if value==1){
cout <<restOfTheLine<<endl;
}
My file has these lines.I try to remove extra line in the end, in notepad/gedit, however, after saving it automatically adds up there.
one
two
three
Code:
void help::read_ref(const char* file_name){
std::ifstream file_handle;
file_handle.open(file_name);
std::string line,name;
getline(file_handle,line);
while(!file_handle.eof()){
[code]......
when I print size of map, it comes out to be an extra then what is should be.
std::map<std::String,std::string> ->is my map
on the contrary if I use Code: file_handle >> line; I get correct number of entries in map.
My doubt: getline, automatically finds and in last, it finds a , why it doesn't end the iteration?
I have faced this issue many number of times.
Code: line[0]=='>' I am making this check, then also, I get a null string as key in my map.
I have printed key with their index, using Code: map iterator .
I'm currently working on making a program that is run through a GUI run through the command line. The program basically takes an app file and a boot file and runs it through a bunch of functions and generates a new outfile. Anyway I'm new to C and can't figure out how to code it so I can type the two file paths into the command line and read them into the function. Is it possible to do this within the "if else" statement?
Code:
int main(int argc, char *argv[]){
const char * const SrcFilePath;
const char * const SRecordPath;
const char * const FopIspFilePath;
[Code] ....
This is about reading a "txt file" and storing the contents in a variable. But i've got problems with it because normally, it is space delimited, that is, values separated by spaces are considered different values. How am I going to make C++ read the whole line including spaces?
View 14 Replies View Relatedfinding the last line of the code? I have a program with two functions that open and display a joke.txt and punchline.txt file. My joke function (which reads the entire file) works fine. The punchline function, however, does not.
void displayPunch(fstream &file)
{
char ch;
string fileLine;
bool isLine = true;
file.seekg(0L, ios::end);
while(isLine)
{
file.seekg(-1L, ios::cur);
[code]....
The file, punchline.txt, has a bunch of garbage strings with one real string at the end. I need extract and display only the final line of that file.
I'm making a command line program for Maemo but have got a problem reading the args.
main.cpp
Code:
#include <cstdlib>
#include <string>
#include <sys/stat.h>
#include <sys/param.h>
#include <iostream>
#include "exceptions.h"
using namespace std;
struct settings {
//settings() : force(false), deps(false), repo(false) {}
[Code] ....
exceptions.cpp contains bodies of these functions.
Unfortunately the program doesn't seem to recognize the arguments
Code:
marcin@marcin:~/proj/meeinstall$ ./meeinstall -h
-h
Filename not provided.
Exiting...
How can I fix it?
I know how to do it in C, but in C++?
Here is my code. Let the variables be of type double.
Code:
while(infile) // Will read the last line twice
{
if(!N)//Read first line of file
{
infile >> d;
infile >> N;
infile >> epsilon;
infile >> t;
[Code] .....
i am trying to read a string using fgets and storing in an array i want to prevent fgets from storing the new line character on the array using the shortest means possible..
View 2 Replies View Relatedi would like to read the content of a text file data.txt (line by line ) directly from the command line using this command: a.exe < data.txt.
What could be the c++ code to read/get the content of these lines (without using ifstream). The treatment of the lines is not a problem for me but i really don't know how to access the content of the file from the c++ code
My question is how can i read one line from a ".txt" file? To be more clear, i'm trying to write a hangman game. Therefore I'm trying to get words from a "wordlist.txt" file i created. I know a little bit about ifstream, ofstream and fstream. So my function i created to get a random line from this txt (not-completed yet since i don't know how to get that randomized line);
void grw() {
int line;
srand (time(NULL));
line = (rand() % 7972) + 1;
ifstream wordlist;
wordlist.open("wordlist.txt");
}
I created a variable called 'line' for the line number and randomized it (there are 7972 words in ".txt" file). So what i want to do now is to get the word on that line.
I have attached the file that I need to read into a data structure. In the example I am just printing it to the screen. This following code has worked for me before, but now isn't. I have tried in visual studios, and on unix, and neither are running it. I ultimately need it to run on unix.
Example file:
word
book
programming
Here is my function to read in the file.
ifstream file;
string line;
file.open("words.txt");
if(file.is_open()){
while(!file.eof()){
getline(file, line);
cout << line <<endl;
}
}
file.close();
I have a file with such a format:
string string 8 7 2
string string 7 12 19 -4
string string 1
As you can see I don't know how many numbers there are at the end. I have this code now:
while(!in.eof()) {
kr = 0;
getline(in, pavard, ','); getline(in, vard, ','); getline(in, gr, ',');
while(in.peek()) {
in >> k;
kr += k;
}
in.ignore();
}
in.close();
I tried various combinations with peek() function, but nothing worked.
Why this code outputs 7 lines (the last line twice) while the file contains 6 lines?
cout << "read msgfile
";
ifstream msgfile ("script1.msg");
while (msgfile.good()) //if not at end of file, continue reading {
// load vector with deffile
msgfile >> line;
vectormsgfile.push_back (line);
cout << line << "
";
}
msgfile.close();
I'm trying to read a file from the 2nd argument, skipping the first line of the file since it's the name of the columns, and separate each line as a token, by date, subject, startTime, endTime, and location.Here's my code that I got so far:
Code:
void readAppointment(){
if (arg != 2)
exit;
else {
FILE *fp;
fp = fopen( argv[1], "r");
char line[999];
[code]....
How can I make fgets stop reading when it reaches a new line? Right now it will read the new line and continue until the buffer is full. I was thinking something like this.
Code:
while(fp!='
'){
fgets(password, 256, fp);
}