43: ls

This exercise is pending. Quick notes about this exercise:

• My implemention is at https://lcthw.dev/go/go-coreutils
• https://www.gnu.org/software/coreutils/manual/html_node/ls-invocation.html
• os -- https://pkg.go.dev/os@go1.25.3
• path -- probably all of them use it
• regex -- https://pkg.go.dev/regexp@go1.25.3

The Code

View Source file go-coreutils/ls/main.go Only

package main

import (
  "fmt"
  "io/fs"
  "path/filepath"
  "flag"
)

func main() {
    var recurse bool

    flag.BoolVar(&recurse, "R", false, "recursive listing")
    flag.Parse()

    paths := flag.Args()

    if len(paths) == 0 {
        paths = append(paths, ".")
    }

    for _, what := range paths {
        if flag.NArg() > 1 {
            fmt.Printf("\n%s:\n", what)
        }

        filepath.WalkDir(what, func (path string, d fs.DirEntry, err error) error {
            if path == what { return nil }

            if d.IsDir() && recurse {
                fmt.Printf("\n%s:\n", path)
            } else if d.IsDir() {
                fmt.Printf("%s\n", filepath.Base(path))
                return fs.SkipDir
            } else {
                fmt.Printf("%s\n", filepath.Base(path))
            }

            return nil
        })
    }
}