listen/main.go

112 lines
2.9 KiB
Go

package main
import (
"crypto/sha256"
"fmt"
"io"
"io/fs"
"log"
"os"
"path/filepath"
"time"
flags "github.com/jessevdk/go-flags"
)
const VERSION string = "v0.1.0"
var opts struct {
Version bool `short:"v" long:"version" description:"Displays version info and exits"`
Quiet bool `short:"q" long:"quiet" description:"Suppresses all non-error output"`
Files []string `short:"f" long:"file" description:"File(s) to listen to (watch)" value-name:"FILE"`
Condition string `short:"w" long:"when" description:"If multiple files are specified, choose if any file or all files specified are needed to trigger COMMAND" default:"any" choice:"any" choice:"all"`
Checksum bool `short:"c" long:"checksum" description:"Use checksum to determine when file(s) are changed instead of writes/modification time"`
Interval string `short:"i" long:"interval" description:"Use this time interval (ex. 5m30s, 1s) between filesystem checks instead of watching kernel events. If the interval is effectively 0 (the default), kernel events are used" default:"0s"`
}
func validateArgs(files []string, interval string) error {
// file checks
if len(files) <= 0 {
fmt.Println("listen: at least one file (-f) is required")
return flags.ErrCommandRequired
}
for _, file := range files {
info, err := os.Stat(file)
if err != nil {
fmt.Printf("listen: %s\n", err)
return err
}
if info.IsDir() {
fmt.Printf("listen: %s: not a file\n", file)
return fs.ErrInvalid
}
_, err = os.Open(file)
if err != nil {
fmt.Printf("listen: %s\n", err)
return err
}
}
// interval checks
if _, err := time.ParseDuration(interval); err != nil {
fmt.Printf("listen: %s\n", err)
return err
}
return nil
}
func main() {
parser := flags.NewParser(&opts, flags.Default)
parser.Usage = "[OPTIONS] -- [COMMAND]"
remaining, err := parser.Parse()
if err == nil {
if opts.Version {
fmt.Printf("listen %s\n", VERSION)
} else if err := validateArgs(opts.Files, opts.Interval); err == nil {
var filesMap map[string]bool = make(map[string]bool)
var cksumMap map[string][]byte = make(map[string][]byte)
var intervalMap map[string]time.Time = make(map[string]time.Time)
intervalDuration, _ := time.ParseDuration(opts.Interval)
success := true
for _, file := range opts.Files {
hasher := sha256.New()
f, err := os.Open(file)
if err != nil {
success = false
break
}
defer f.Close()
s, err := os.Stat(file)
if err != nil {
success = false
break
}
if _, err := io.Copy(hasher, f); err != nil {
log.Fatal(err)
}
abs, err := filepath.Abs(file)
if err == nil {
filesMap[abs] = false
cksumMap[abs] = hasher.Sum(nil)
intervalMap[abs] = s.ModTime()
} else {
success = false
break
}
}
if success {
l := Listen{filesMap, cksumMap, intervalMap, opts.Condition, opts.Checksum, intervalDuration, remaining, opts.Quiet}
l.Run()
}
}
}
}