Go Q & A


How do you perform concurrent file I/O in Go?

In Go, performing concurrent file I/O operations involves leveraging Go’s built-in concurrency primitives such as goroutines and channels to execute file I/O operations concurrently while ensuring data consistency, synchronization, and error handling.


Here’s a general approach for performing concurrent file I/O in Go:


  • Goroutines: Use goroutines to execute file I/O operations concurrently. Goroutines are lightweight, independently executing functions that enable concurrent execution of tasks without blocking the main program execution flow.
  • Channels: Use channels to communicate and synchronize data between concurrent goroutines. Channels provide a safe and efficient way to pass data between goroutines and coordinate their execution.
  • Error Handling: Implement robust error handling mechanisms to handle errors and exceptions that may occur during file I/O operations. Proper error handling ensures that errors are propagated correctly and handled appropriately by the application.


Here’s an example demonstrating how to perform concurrent file I/O operations in Go using goroutines and channels:



package main

import (

func readFile(filename string, resultChan chan []byte, wg *sync.WaitGroup) {
    defer wg.Done()
    data, err := ioutil.ReadFile(filename)
    if err != nil {
        fmt.Printf("Error reading file %s: %v\n", filename, err)
    resultChan <- data

func main() {
    var wg sync.WaitGroup
    resultChan := make(chan []byte)

    files := []string{"file1.txt", "file2.txt", "file3.txt"}

    for _, file := range files {
        go readFile(file, resultChan, &wg)

    go func() {

    for data := range resultChan {

    fmt.Println("File reading completed.")

In this example, the readFile function reads the contents of a file concurrently using goroutines. The resultChan channel is used to receive the data read from each file, and the sync.WaitGroup is used to wait for all goroutines to complete before closing the channel.


By leveraging goroutines, channels, and synchronization primitives provided by Go’s standard library, developers can efficiently perform concurrent file I/O operations, maximize CPU utilization, and improve the performance and scalability of file processing tasks in Go applications.

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Over 5 years of experience in Golang. Led the design and implementation of a distributed system and platform for building conversational chatbots.