摘要：
要求：需要监听目录中的所有文件。当文件大小增加到某个阈值时，文件将被清空。需要引入第三方包：“github.com/howeyc/fsnotify”代码如下：packagemainimport（“log”“github.com/showeyc/fsnotify”“os”“fmt”“strconv”）funage（）｛fmt.Println（“”）fmt.Printf（“Usag”
需求：
需要监听一个目录中所有文件，当文件大小增加到一定阀值，则将文件清空。
需要引入第三方包："github.com/howeyc/fsnotify"
代码如下：
package main
import (
"log"
"github.com/howeyc/fsnotify"
"os"
"fmt"
"strconv"
)
func usage() {
fmt.Println("")
fmt.Printf("Usage: %s Montior-directory file-max-bytes-limit
",os.Args[0])
fmt.Println("For example:")
fmt.Printf("%s /opt/logs 1024
",os.Args[0])
os.Exit(1)
}
func isDir(dirname string) bool {
fhandler, err := os.Stat(dirname);
if(! (err == nil || os.IsExist(err)) ) {
return false
}else {
return fhandler.IsDir()
}
}
func isFile(filename string) bool {
fhandler, err := os.Stat(filename);
if(! (err == nil || os.IsExist(err)) ) {
return false
}else if (fhandler.IsDir()){
return false
}
return true
}
func emptiedFile(filename string) bool {
FN,err := os.Create(filename)
defer FN.Close()
if err != nil {
return false
}
fmt.Fprint(FN,"")
return true
}
func getFileByteSize(filename string) (bool,int64) {
if (! isFile(filename)) {
return false,0
}
fhandler, _ := os.Stat(filename);
return true,fhandler.Size()
}
func main() {
var maxByte int64 = 1024*1024
if (len(os.Args) < 2) {
usage()
}
if (len(os.Args) >= 3) {
maxByte_,err := strconv.Atoi(os.Args[2])
if err != nil {
log.SetPrefix("[ERROR] ")
log.Println(os.Args[2],"Is not a legitimate int number")
usage()
}
maxByte = int64(maxByte_)
}
dirpath := os.Args[1]
if (!isDir(dirpath)){
log.SetPrefix("[ERROR] ")
log.Println(dirpath,"Is not a legitimate directory")
usage()
}
watcher, err := fsnotify.NewWatcher()
if err != nil {
log.Fatal(err)
}
done := make(chan bool)
//Process event
go func() {
for {
select {
case ev := <-watcher.Event:
if(ev.IsModify()){
_,size := getFileByteSize(ev.Name)
log.Println("event:",ev,",byte:",size)
if (size >= maxByte){
if ( ! emptiedFile(ev.Name) ) {
log.SetPrefix("[ERROR] ")
log.Printf("%s :Can not empty file
",ev.Name)
}
}
}
case err := <-watcher.Error:
log.Println("error:",err)
}
}
}()
err = watcher.Watch(dirpath)
if err != nil {
log.Fatal(err)
}
<-done
watcher.Close()
}
运行实例：
