66-temporary-files-and-directories.md

This Go program demonstrates the usage of temporary files and directories using the os and filepath packages. Let's go through the code with inline comments and explanations:

// Importing necessary packages.
import (
	"fmt"
	"os"
	"path/filepath"
)

// Function to check and panic if an error occurs.
func check(e error) {
	if e != nil {
		panic(e)
	}
}

// Main function where the execution of the program begins.
func main() {
	// Creating a temporary file with the prefix "sample" in the default temporary directory.
	f, err := os.CreateTemp("", "sample")
	check(err)

	fmt.Println("Temp file name:", f.Name())

	// Defer removing the temporary file at the end of the program.
	defer os.Remove(f.Name())

	// Writing data to the temporary file.
	_, err = f.Write([]byte{1, 2, 3, 4})
	check(err)

	// Creating a temporary directory with the prefix "sampledir" in the default temporary directory.
	dname, err := os.MkdirTemp("", "sampledir")
	check(err)

	fmt.Println("Temp dir name:", dname)

	// Defer removing the temporary directory and its contents at the end of the program.
	defer os.RemoveAll(dname)

	// Creating a file inside the temporary directory and writing data to it.
	fname := filepath.Join(dname, "file1")
	err = os.WriteFile(fname, []byte{1, 2}, 0666)
	check(err)
}

output

Temp file name: ..\..\....\.......\Temp\sample4108738795
Temp dir name: ..\..\....\.......\Temp\sampledir1931724887

Explanation:

1. Creating a Temporary File:

   • os.CreateTemp("", "sample") creates a temporary file in the default temporary directory with the prefix "sample."
   • defer os.Remove(f.Name()) defers the removal of the temporary file until the end of the program.

2. Writing Data to the Temporary File:

   • f.Write([]byte{1, 2, 3, 4}) writes data to the temporary file.

3. Creating a Temporary Directory:

   • os.MkdirTemp("", "sampledir") creates a temporary directory in the default temporary directory with the prefix "sampledir."
   • defer os.RemoveAll(dname) defers the removal of the temporary directory and its contents until the end of the program.

4. Creating a File Inside the Temporary Directory:

   • filepath.Join(dname, "file1") constructs the path for a file inside the temporary directory.
   • os.WriteFile(fname, []byte{1, 2}, 0666) creates the file and writes data to it.

This program showcases how to create and work with temporary files and directories in Go.