90 lines
1.8 KiB
Go
90 lines
1.8 KiB
Go
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
|
|
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
|
|
|
|
// See page 249.
|
|
|
|
// The du2 command computes the disk usage of the files in a directory.
|
|
package main
|
|
|
|
// The du2 variant uses select and a time.Ticker
|
|
// to print the totals periodically if -v is set.
|
|
|
|
import (
|
|
"flag"
|
|
"fmt"
|
|
"os"
|
|
"path/filepath"
|
|
"time"
|
|
)
|
|
|
|
// !+
|
|
var verbose = flag.Bool("v", false, "show verbose progress messages")
|
|
|
|
func main() {
|
|
// ...start background goroutine...
|
|
|
|
flag.Parse()
|
|
roots := flag.Args()
|
|
if len(roots) == 0 {
|
|
roots = []string{"."}
|
|
}
|
|
|
|
// Traverse the file tree.
|
|
fileSizes := make(chan int64)
|
|
go func() {
|
|
for _, root := range roots {
|
|
walkDir(root, fileSizes)
|
|
}
|
|
close(fileSizes)
|
|
}()
|
|
|
|
// Print the results periodically.
|
|
var tick <-chan time.Time
|
|
if *verbose {
|
|
tick = time.Tick(500 * time.Millisecond)
|
|
}
|
|
var nfiles, nbytes int64
|
|
loop:
|
|
for {
|
|
select {
|
|
case size, ok := <-fileSizes:
|
|
if !ok {
|
|
break loop // fileSizes was closed
|
|
}
|
|
nfiles++
|
|
nbytes += size
|
|
case <-tick:
|
|
printDiskUsage(nfiles, nbytes)
|
|
}
|
|
}
|
|
printDiskUsage(nfiles, nbytes) // final totals
|
|
}
|
|
|
|
//!-
|
|
|
|
func printDiskUsage(nfiles, nbytes int64) {
|
|
fmt.Printf("%d files %.1f GB\n", nfiles, float64(nbytes)/1e9)
|
|
}
|
|
|
|
// walkDir recursively walks the file tree rooted at dir
|
|
// and sends the size of each found file on fileSizes.
|
|
func walkDir(dir string, fileSizes chan<- int64) {
|
|
for _, entry := range dirents(dir) {
|
|
if entry.IsDir() {
|
|
subdir := filepath.Join(dir, entry.Name())
|
|
walkDir(subdir, fileSizes)
|
|
} else {
|
|
fileSizes <- entry.Size()
|
|
}
|
|
}
|
|
}
|
|
|
|
// dirents returns the entries of directory dir.
|
|
func dirents(dir string) []os.FileInfo {
|
|
entries, err := os.ReadDir(dir)
|
|
if err != nil {
|
|
fmt.Fprintf(os.Stderr, "du: %v\n", err)
|
|
return nil
|
|
}
|
|
return entries
|
|
}
|