main.go (view raw)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 | package main
import (
"context"
"errors"
"io"
"log"
"os"
"os/signal"
"slices"
"strings"
"sync"
"syscall"
"time"
"github.com/fsnotify/fsnotify"
"github.com/jessevdk/go-flags"
"alin.ovh/erl/command"
"alin.ovh/erl/state"
"alin.ovh/erl/watcher"
)
type Options struct {
Exec string `short:"x" long:"exec" description:"command to execute on file change"`
Quiet bool `short:"q" long:"quiet" description:"suppress own output"`
Verbose bool `short:"v" long:"verbose" description:"verbose output (print events)"`
}
func Start(ctx context.Context, verbose *log.Logger, w watcher.Watcher, sm *state.StateMachine) {
var wg sync.WaitGroup
wg.Add(1)
go func(events <-chan watcher.Event, errors <-chan error) {
defer wg.Done()
sm.SendEvent(state.Start)
for {
select {
case <-ctx.Done():
sm.SendEvent(state.Signal)
return
case event, ok := <-events:
if !ok {
return
}
// skip if _only_ chmod
if event.Op == fsnotify.Chmod {
continue
}
verbose.Printf("event: %s %s\n", event.Name, event.Op.String())
if event.Op.Has(fsnotify.Create) {
stat, err := os.Stat(event.Name)
if err != nil {
log.Printf("Error getting file info: %v\n", err)
continue
}
if stat.IsDir() {
err = w.AddRecursive(event.Name)
if err != nil {
log.Printf("Error adding directory to watcher: %v\n", err)
}
}
}
if event.Op.Has(fsnotify.Remove) {
for _, dir := range w.WatchList() {
if strings.HasPrefix(dir, event.Name) {
err := w.Remove(dir)
if err != nil {
log.Printf("Error removing directory from watcher: %v\n", err)
}
}
}
}
sm.SendEvent(state.Restart)
time.Sleep(100 * time.Millisecond)
case err, ok := <-errors:
if !ok {
return
}
log.Printf("Error: %v\n", err)
}
}
}(w.Monitor())
err := w.AddRecursive(".")
if err != nil {
log.Fatalf("failed to add directory to watcher: %v", err)
}
<-ctx.Done()
log.Println("shutting down")
sm.SendEvent(state.Signal)
wg.Wait()
}
func main() {
var opts Options
log.SetFlags(log.Lmsgprefix)
fp := flags.NewParser(&opts, flags.Default)
args, err := fp.Parse()
if err != nil {
if errors.Is(err, flags.ErrHelp) {
os.Exit(0)
}
log.Fatalf("failed to parse flags: %v", err)
}
program := opts.Exec
if program == "" {
program = "go"
if len(args) == 0 {
args = []string{"run", "."}
} else {
args = slices.Insert(args, 0, "run")
}
}
watcher, err := watcher.New()
if err != nil {
log.Fatal(err)
}
defer watcher.Close()
ctx, cancel := signal.NotifyContext(
context.Background(),
os.Interrupt,
syscall.SIGHUP,
syscall.SIGTERM,
)
defer cancel()
copts := command.Options{}
if opts.Quiet {
copts.Output = io.Discard
}
var logger *log.Logger
if opts.Verbose {
logger = log.New(os.Stderr, "", 0)
} else {
logger = log.New(io.Discard, "", 0)
}
cmd := command.New(program, args, copts)
sm := state.New(cmd, log.New(os.Stderr, "state: ", log.Lmsgprefix))
Start(ctx, logger, watcher, sm)
}
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