38: stat Then du

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/du-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 stat Code

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

package main

import (
  "fmt"
  "os"
  "flag"
  "log"
  "io/fs"
)

func PrintStat(stat fs.FileInfo) {
  fmt.Printf("File: %s\nSize: %d\nAccess: %v\nModify: %v",
   stat.Name(),
   stat.Size(),
   stat.Mode(),
   stat.ModTime())
}

func main() {
  flag.Parse()
  files := flag.Args()

  for _, fname := range files {
    f, err := os.Open(fname)
    if err != nil { log.Fatal(err) }
    defer f.Close()

    stats, err := f.Stat()
    if err != nil { log.Fatal(err) }

    PrintStat(stats)
  }
}

The du Code

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

package main

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

func StatDir(target_path string) error {
  var cur_dir string
  var cur_size int64

  // NOTE: cover the difference betweeen filepath.WalkDir and fs.WalkDir

  err := filepath.WalkDir(target_path, func (path string, d fs.DirEntry, err error) error {
    if d.IsDir() {
      if cur_dir != path {
        loc := filepath.Join(target_path, cur_dir)
        fmt.Printf("%s %d\n", loc, cur_size / 1024)
        cur_dir = path
        cur_size = 0
      }
    } else {
      info, err := d.Info()
      if err != nil { return nil }
      cur_size += info.Size()
    }

    return nil
  })

  return err
}

func main() {
  flag.Parse()
  paths := flag.Args()

  for _, path := range paths {
    err := StatDir(path)
    if err != nil { log.Fatal(err) }
  }
}