/
xplor.go
468 lines (427 loc) · 8.72 KB
/
xplor.go
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// 2010 - Mathieu Lonjaret
// 2018 - Martin Kühl
// The xplor program is an acme files explorer, tree style.
package main
import (
"bytes"
"flag"
"fmt"
"io"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
"regexp"
"strings"
"9fans.net/go/acme"
"9fans.net/go/plan9"
"9fans.net/go/plumb"
)
const (
this = "xplor"
tag = "Get All Up Cd Win Xplor "
tab = "\t"
flagFile = " "
flagBroken = "X"
flagLess = "▸"
flagMore = "▾"
)
var (
PLAN9 = os.Getenv("PLAN9")
all = flag.Bool("a", false, "Include directory entries whose names begin with a dot (.)")
open = map[string]bool{}
win *acme.Win
root string
)
func usage() {
fmt.Fprintf(os.Stderr, "usage: %s [options] [path]\n", this)
flag.PrintDefaults()
os.Exit(2)
}
func main() {
log.SetFlags(0)
flag.Usage = usage
flag.Parse()
if err := setup(); err != nil {
log.Fatal(err)
}
defer win.CloseFiles()
for e := range win.EventChan() {
if err := handle(e); err != nil {
log.Print(err)
}
}
}
// Setup
func setup() error {
if err := findRoot(); err != nil {
return err
}
return openWindow()
}
func findRoot() error {
switch flag.NArg() {
case 0: // start at .
var err error
root, err = os.Getwd()
return err
case 1: // start at path
var err error
root = filepath.Clean(flag.Arg(0))
if !filepath.IsAbs(root) {
root, err = filepath.Abs(root)
if err != nil {
return err
}
}
info, err := os.Stat(root)
if err != nil {
return err
}
if !info.IsDir() {
return fmt.Errorf("%s: Not a directory", root)
}
return nil
default:
usage()
return nil
}
}
func openWindow() error {
var err error
win, err = acme.New()
if err != nil {
return err
}
if err := win.Fprintf("tag", "%s", tag); err != nil {
return err
}
if err := win.Ctl("dump %s", this); err != nil {
return err
}
if err := win.Ctl("dumpdir %s", root); err != nil {
return err
}
return draw()
}
// Drawing Structure
func draw() error {
if err := win.Name("%s/-%s", root, this); err != nil {
return err
}
var b bytes.Buffer
if err := printRoot(&b); err != nil {
return err
}
if _, err := win.Write("data", b.Bytes()); err != nil {
return err
}
if err := win.Ctl("clean"); err != nil {
return err
}
return selectEntry(root)
}
func redraw() error {
win.Clear()
return draw()
}
func redrawEntry(path string, info os.FileInfo, addr string, depth int) error {
if err := selectEntryRegion(addr, depth); err != nil {
return err
}
var b bytes.Buffer
if err := printEntry(&b, path, info, depth); err != nil {
return err
}
_, err := win.Write("data", b.Bytes())
return err
}
// Directory Listing
func printRoot(w io.Writer) error {
if err := printContents(w, root, 0); err != nil {
return err
}
_, err := io.WriteString(w, "\n") // so acme can write after the last entry
return err
}
func printContents(w io.Writer, dir string, depth int) error {
infos, err := ioutil.ReadDir(dir)
if err != nil {
return err
}
for _, info := range infos {
name := info.Name()
path := filepath.Join(dir, name)
if info.Mode()&os.ModeSymlink != 0 {
// The error from os.Stat is ignored because logging it just spams the +Errors window
// on each repaint.
info, _ = os.Stat(path)
}
if err := printEntry(w, path, info, depth); err != nil {
return err
}
}
return nil
}
func printEntry(w io.Writer, path string, info os.FileInfo, depth int) error {
name := filepath.Base(path)
if strings.HasPrefix(name, ".") && !*all {
return nil
}
flag := flagFile
if info == nil {
flag = flagBroken
} else if info.IsDir() {
name += "/"
flag = flagLess
if open[path] {
flag = flagMore
}
}
tabs := strings.Repeat(tab, depth)
if _, err := fmt.Fprintf(w, "%s %s%s\n", flag, tabs, name); err != nil {
return err
}
if flag == flagMore {
return printContents(w, path, depth+1)
}
return nil
}
// Buffer Interaction
func toggleAll() error {
*all = !*all
return redraw()
}
func goUp() error {
root = filepath.Join(root, "..")
return redraw()
}
func cd(dir string) error {
root = dir
return redraw()
}
// Line Interaction
func look(addr string) error {
path, depth, err := abspath(addr)
if err != nil {
return err
}
info, err := os.Stat(path)
if err != nil {
return err
}
if !info.IsDir() {
return send(path)
}
open[path] = !open[path]
if err := redrawEntry(path, info, addr, depth); err != nil {
return err
}
return selectEntry(path)
}
func print(addr string) error {
path, _, err := abspath(addr)
if err != nil {
return err
}
log.Print(path)
return nil
}
// Selection
func selectEntry(path string) error {
var steps strings.Builder
steps.WriteString("0") // beginning
for depth, name := range split(path) {
tabs := strings.Repeat(tab, depth)
fmt.Fprintf(&steps, "+/^..%s%s/", tabs, regexp.QuoteMeta(name)) // next entry
}
if err := win.Addr("%s", steps.String()); err != nil {
return err
}
return win.Ctl("dot=addr\nshow")
}
func selectEntryRegion(addr string, depth int) error {
var end strings.Builder // next line with at most depth tabs
end.WriteString("^$") // last line
for i := 0; i <= depth; i++ {
tabs := strings.Repeat(tab, i)
fmt.Fprintf(&end, "|^..%s[^%s]", tabs, tab) // line with i tabs
}
return win.Addr("%s-/^/+/^/,%s+/%s/-/^/", addr, addr, end.String())
}
// Parsing Structure
// Determine entry name, depth
func entry(format string, args ...interface{}) (string, int, error) {
fail := func(err error) (string, int, error) {
return "", 0, err
}
if err := win.Addr(format, args...); err != nil {
return fail(err)
}
buf, err := win.ReadAll("xdata")
if err != nil {
return fail(err)
}
line := strings.TrimSuffix(string(buf), "\n")
if !strings.Contains(line, " ") {
return fail(nil)
}
line = strings.SplitN(line, " ", 2)[1]
name := strings.TrimLeft(line, tab)
depth := (len(line) - len(name)) / len(tab)
return name, depth, nil
}
// Determine absolute path, depth
func abspath(addr string) (string, int, error) {
fail := func(err error) (string, int, error) {
return "", 0, err
}
dir, depth, err := entry("%s-+", addr) // line containing addr
if err != nil {
return fail(err)
}
if dir == "" {
return fail(nil)
}
for level := depth; level > 0; level-- {
tabs := strings.Repeat(tab, level-1)
parent, _, err := entry("%s-/^..%s[^%s]/-+", addr, tabs, tab) // line at depth before addr
if err != nil {
return fail(err)
}
dir = filepath.Join(parent, dir)
}
return filepath.Join(root, dir), depth, nil
}
// Determine components of path
func split(path string) []string {
if path == root {
return []string{}
}
path = strings.TrimPrefix(path, root+"/")
return strings.Split(path, string(filepath.Separator))
}
// System Interaction
func send(path string) error {
port, err := plumb.Open("send", plan9.OWRITE)
if err != nil {
return err
}
defer port.Close()
msg := &plumb.Message{
Src: this,
Dst: "",
Dir: root,
Type: "text",
Data: []byte(path),
}
return msg.Send(port)
}
func run(exe, dir string) error {
cmd := exec.Command(exe)
cmd.Dir = dir
return cmd.Start()
}
// Event Handling
func handle(e *acme.Event) error {
switch e.C2 {
// exec
// - tag
case 'x':
switch string(e.Text) {
case "Del":
return win.Del(true)
case "Get":
return redraw()
case "All":
return toggleAll()
case "Up":
return goUp()
case "Cd":
dir, err := loc(e)
if err != nil {
return err
}
return cd(dir)
case "Win":
exe := filepath.Join(PLAN9, "bin", "win")
dir, err := loc(e)
if err != nil {
return err
}
return run(exe, dir)
case "Xplor":
exe := this
dir, err := loc(e)
if err != nil {
return err
}
return run(exe, dir)
default:
return win.WriteEvent(e)
}
// - body
case 'X':
if isComplex(e) {
return win.WriteEvent(e)
}
return print(q(e))
// look
// - tag
case 'l':
return win.WriteEvent(e)
// - body
case 'L':
if isComplex(e) {
return win.WriteEvent(e)
}
return look(q(e))
default:
return nil
}
}
func isComplex(e *acme.Event) bool {
if e.OrigQ0 != e.OrigQ1 {
// user has selected text
return true
}
if e.Flag&8 != 0 {
// user has chorded argument
return true
}
return false
}
func q(e *acme.Event) string {
return fmt.Sprintf("#%d", e.OrigQ0)
}
func loc(e *acme.Event) (string, error) {
fail := func(err error) (string, error) {
return "", err
}
if e.Flag&8 == 0 {
return fail(nil)
}
loc := string(e.Loc)
if loc == "" {
return fail(nil)
}
prefix := fmt.Sprintf("%s/-%s:", root, this)
if !strings.HasPrefix(loc, prefix) {
return fail(nil)
}
loc = strings.TrimPrefix(loc, prefix)
addrs := strings.SplitN(loc, ",", 2)
dir, _, err := abspath(addrs[0])
if err != nil {
return fail(err)
}
info, err := os.Stat(dir)
if err != nil {
return fail(err)
}
if info.IsDir() {
return dir, nil
}
return filepath.Dir(dir), nil
}