64-file-paths.md

This Go code demonstrates various functions from the filepath package for working with file paths. Let's go through the code with inline comments and explanations:

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

// The main function, where the execution of the program begins.
func main() {
	// Joining path elements to form a path.
	p := filepath.Join("dir1", "dir2", "filename")
	fmt.Println("p:", p)

	// Joining path elements with extra separators.
	fmt.Println(filepath.Join("dir1//", "filename"))
	// Resolving ".." in the path.
	fmt.Println(filepath.Join("dir1/../dir1", "filename"))

	// Extracting the directory and base name from a path.
	fmt.Println("Dir(p):", filepath.Dir(p))
	fmt.Println("Base(p):", filepath.Base(p))

	// Checking if a path is absolute.
	fmt.Println(filepath.IsAbs("dir/file"))
	fmt.Println(filepath.IsAbs("/dir/file"))

	// Extracting the extension from a filename.
	filename := "config.json"
	ext := filepath.Ext(filename)
	fmt.Println(ext)

	// Removing the extension from a filename.
	fmt.Println(strings.TrimSuffix(filename, ext))

	// Finding the relative path between two paths.
	rel, err := filepath.Rel("a/b", "a/b/t/file")
	if err != nil {
		panic(err)
	}
	fmt.Println(rel)

	// Handling a case where the paths are not relative.
	rel, err = filepath.Rel("a/b", "a/c/t/file")
	if err != nil {
		panic(err)
	}
	fmt.Println(rel)
}

Output

p: dir1\dir2\filename
dir1\filename
dir1\filename
Dir(p): dir1\dir2
Base(p): filename
false
false
.json
config
t\file
..\c\t\file

Explanation:

1. Joining Paths:

   • filepath.Join("dir1", "dir2", "filename") joins path elements to form a path.

2. Handling Extra Separators:

   • filepath.Join("dir1//", "filename") demonstrates joining with extra separators.
   • filepath.Join("dir1/../dir1", "filename") resolves ".." in the path.

3. Extracting Directory and Base Name:

   • filepath.Dir(p) extracts the directory from the path.
   • filepath.Base(p) extracts the base name (filename) from the path.

4. Checking if Path is Absolute:

   • filepath.IsAbs("dir/file") checks if the path is absolute (false).
   • filepath.IsAbs("/dir/file") checks if the path is absolute (true).

5. Extracting Extension:

   • filepath.Ext(filename) extracts the extension from a filename.

6. Trimming Suffix:

   • strings.TrimSuffix(filename, ext) removes the extension from a filename.

7. Relative Paths:

   • filepath.Rel("a/b", "a/b/t/file") finds the relative path between two paths.
   • filepath.Rel("a/b", "a/c/t/file") demonstrates handling a case where the paths are not relative.