C++ (Cpp) file::open Examples

Programming Language: C++ (Cpp)

Class/Type: file

Method/Function: open

Examples at hotexamples.com: 2

C++ has a built-in library called the Standard Template Library (STL) that provides file input/output capabilities. The most commonly used functions for opening and manipulating files are included in the fstream library, which is part of the STL.

Examples of opening a file using fstream:

1. Reading file:

#include 
#include 

int main() {
    std::ifstream input_file("example.txt");
    
    if (!input_file.is_open()) {
        std::cerr << "Error opening file\n";
        return 1;
    }
    
    std::string line;
    while (std::getline(input_file, line)) {
        std::cout << line << '\n';
    }
    
    input_file.close();
    return 0;
}

This code opens a file named "example.txt" and reads each line from the file, printing it to the console.

2. Writing file:

#include 
#include 

int main() {
    std::ofstream output_file("output.txt");
    
    if (!output_file.is_open()) {
        std::cerr << "Error opening file\n";
        return 1;
    }
    
    output_file << "Hello, world!\n";
    
    output_file.close();
    return 0;
}

This code creates a new file named "output.txt" and writes the string "Hello, world!" to it. In both examples, we used the fstream library to open the file and verify that it was successfully opened. We also closed the file using the `close()` function when we were finished accessing it.

C++ (Cpp) file::open - 2 examples found. These are the top rated real world C++ (Cpp) examples of file::open from package poedit extracted from open source projects. You can rate examples to help us improve the quality of examples.

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Example #1

Show file

File: binary-file-read-and-transmit.c Project: cancapture/CANCapture-Resources

//This function is called when a new capture is started
//"block" holds an object representing the current script block on the flowchart
//Type "block." for a list of available functions for use in the script
void OnStartCapture(ScriptBlock block)
{
    block.ClearOutputText(); //Clear this script's output window
    block.PrintOutputText("Binary file write started\n", false, false, false, false); //Print to the output window
 
    //Open the firmware image file
    int ret = handle.open(FIRMWARE_FILE_NAME, "rb");
    if (ret != 0) {
        block.PrintOutputText("Failed to open firmware image: \"" + FIRMWARE_FILE_NAME + "\"\n", true, false, false, true);
        bFileOpen = false;  //mark file as not open
    } else {
        block.PrintOutputText("Sending contents of \"" + FIRMWARE_FILE_NAME + "\" onto the CAN bus\n", false, false, false, true);       
        bFileOpen = true; //mark file as open
    }
}

Example #2

Show file

File: memory.hpp Project: jlpoolen/utsushi

 random_generator ()
 { file_.open ("/dev/urandom", std::ios_base::binary | std::ios_base::in); }