In this article, you will learn and get code to read a file in C++. The program is created in a way that, receives the name of file from user as input, and reads all the content of given file.
To read a text file using a C++ program, a file inside the current directory must be created before executing the program of reading the content of a file.
That is, create a file named codescracker.txt with following content:
Hello C++ This is codescracker.txt File
and save this file inside the current directory. The current directory, means the directory where your C++ source code to read a file, is saved. Because I'm going to save the program given below, in a folder cpp programs of Documents of C-Drive. Here is the snapshot of the folder:
And here is the snapshot of opened codescracker.txt file:
Now let's move on and create a C++ program read this file's content.
This is the program to read the content of a text file in C++. The newly created file, codescracker.txt get read through this program:
// C++ Program to Read a File
// ----codescracker.com----
#include<iostream>
#include<fstream>
#include<stdio.h>
using namespace std;
int main()
{
char fileName[30], ch;
fstream fp;
cout<<"Enter the Name of File: ";
gets(fileName);
fp.open(fileName, fstream::in);
if(!fp)
{
cout<<"\nError Occurred!";
return 0;
}
cout<<"\n------"<<fileName<<"-------\n";
while(fp>>noskipws>>ch)
cout<<ch;
fp.close();
cout<<endl;
return 0;
}
This program was build and run under Code::Blocks IDE. Save this source code in the same folder, cpp programs where the file codescracker.txt is created. To save this source code in that folder, navigate to File→Save file as... in Code::Blocks and type the name of file and click on Save button as shown in the snapshot given below:
After saving the source code, here is its sample run. This is the initial output:
Now supply the input say codescracker.txt as name of file, then press ENTER key to read it
as shown in the snapshot given below:
Note - The statement, fp>>noskipws>>ch reads data from a file in character-by-character manner, without skipping white spaces.
Note - The fstream::in is file opening mode. It opens a file in reading mode only.
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