Writing to a File

· 223 words · 2 minutes read
#close #create #defer #file #log #writestring #os #fsync #write

Often it’s very useful being able to write to a file from a program for logging purposes, saving results or as a data store. This is a little snippet on how to write text/data to a file.

We use the os package to create the file, exiting the program and logging if it can’t do this and printing a string into the file using io.WriteString. We’re also using defer to close the file access once the function has finished running (which is a really neat way of remembering to close files). With a final file sync on close to prevent any un-caught errors (see this post for info).

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package main

import (
    "io"
    "log"
    "os"
)

func main() {
    err := WriteToFile("result.txt", "Hello Readers of golangcode.com\n")
    if err != nil {
        log.Fatal(err)
    }
}

// WriteToFile will print any string of text to a file safely by
// checking for errors and syncing at the end.
func WriteToFile(filename string, data string) error {
    file, err := os.Create(filename)
    if err != nil {
        return err
    }
    defer file.Close()

    _, err = io.WriteString(file, data)
    if err != nil {
        return err
    }
    return file.Sync()
}

Write Text to File in Go

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Author:  Edd Turtle

Edd is the Lead Developer at Hoowla, a prop-tech startup, where he spends much of his time working on production-ready Go and PHP code. He loves coding, but also enjoys cycling and camping in his spare time.

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