func FollowFile(path string, cfg *tf.TfcatConfig) {
if !FileExists(path) {
fmt.Fprintf(os.Stderr, "input file '%s' does not exist.\n", path)
os.Exit(1)
}
watcher, err := fsnotify.NewWatcher()
panicOn(err)
defer watcher.Close()
f, err := os.Open(path)
panicOn(err)
// move to end for tailing
_, err = f.Seek(0, 2)
panicOn(err)
err = watcher.Add(path)
panicOn(err)
fr := tf.NewFrameReader(f, 1024*1024)
var frame tf.Frame
i := int64(1)
nextFrame:
for {
_, _, err, _ = fr.NextFrame(&frame)
if err != nil {
if err == io.EOF {
select {
case event := <-watcher.Events:
if event.Op&fsnotify.Write == fsnotify.Write {
continue nextFrame
}
}
}
fmt.Fprintf(os.Stderr, "tfcat error from fr.NextFrame(): '%v'\n", err)
os.Exit(1)
}
frame.DisplayFrame(os.Stdout, i, cfg.PrettyPrint, cfg.SkipPayload, cfg.Rreadable)
i++
}
}
func main() {
myflags := flag.NewFlagSet("tfcat", flag.ExitOnError)
cfg := &tf.TfcatConfig{}
cfg.DefineFlags(myflags)
err := myflags.Parse(os.Args[1:])
err = cfg.ValidateConfig()
if err != nil {
usage(err, myflags)
}
leftover := myflags.Args()
//Q("leftover = %v", leftover)
if len(leftover) == 0 && cfg.ReadStdin == false {
fmt.Fprintf(os.Stderr, "no input files given\n")
showUse(myflags)
os.Exit(1)
}
GlobalPrettyPrint = cfg.PrettyPrint
if cfg.Follow {
if len(leftover) != 1 {
if cfg.ReadStdin {
fmt.Fprintf(os.Stderr, "cannot follow stdin\n")
showUse(myflags)
os.Exit(1)
}
fmt.Fprintf(os.Stderr, "can only follow a single file\n")
showUse(myflags)
os.Exit(1)
}
FollowFile(leftover[0], cfg)
return
}
if cfg.ReadStdin {
if len(leftover) > 0 {
fmt.Fprintf(os.Stderr, "if reading from stdin, cannot also read from files\n")
showUse(myflags)
os.Exit(1)
}
leftover = []string{"stdin"}
}
if cfg.RawCount > 0 || cfg.RawSkip > 0 {
if len(leftover) != 1 {
fmt.Fprintf(os.Stderr, "can only copy raw messages from one file\n")
showUse(myflags)
os.Exit(1)
}
SendRawBytes(leftover[0], cfg.RawCount, os.Stdout, cfg.RawSkip)
return
}
i := int64(1)
nextfile:
for _, inputFile := range leftover {
f := prepInput(inputFile)
defer f.Close()
//P("starting on inputFile '%s'", inputFile)
fr := tf.NewFrameReader(f, 1024*1024)
var frame tf.Frame
for ; err == nil; i++ {
_, _, err, _ = fr.NextFrame(&frame)
if err != nil {
if err == io.EOF {
continue nextfile
}
fmt.Fprintf(os.Stderr, "tfcat error from fr.NextFrame() at i=%v: '%v'\n", i, err)
os.Exit(1)
}
frame.DisplayFrame(os.Stdout, i, cfg.PrettyPrint, cfg.SkipPayload, cfg.Rreadable)
}
}
}
