// TailFile begins tailing the file. Output stream is made available
// via the `Tail.Lines` channel. To handle errors during tailing,
// invoke the `Wait` or `Err` method after finishing reading from the
// `Lines` channel.
func TailFile(filename string, config Config) (*Tail, error) {
if config.ReOpen && !config.Follow {
panic("cannot set ReOpen without Follow.")
}
t := &Tail{
Filename: filename,
Lines: make(chan *Line),
Config: config}
t.rateMon = new(RateMonitor)
if t.Poll {
t.watcher = watch.NewPollingFileWatcher(filename)
} else {
t.watcher = watch.NewInotifyFileWatcher(filename)
}
if t.MustExist {
var err error
t.file, err = os.Open(t.Filename)
if err != nil {
return nil, err
}
}
go t.tailFileSync()
return t, nil
}
// TailFile begins tailing the file. Output stream is made available
// via the `Tail.Lines` channel. To handle errors during tailing,
// invoke the `Wait` or `Err` method after finishing reading from the
// `Lines` channel.
func TailFile(filename string, config Config) (*Tail, error) {
if !(config.Location == 0 || config.Location == -1) {
panic("only 0/-1 values are supported for Location.")
}
if config.ReOpen && !config.Follow {
panic("cannot set ReOpen without Follow.")
}
t := &Tail{
Filename: filename,
Lines: make(chan *Line),
Config: config}
if t.Poll {
t.watcher = watch.NewPollingFileWatcher(filename)
} else {
t.watcher = watch.NewInotifyFileWatcher(filename)
}
if t.MustExist {
var err error
t.file, err = os.Open(t.Filename)
if err != nil {
return nil, err
}
}
go t.tailFileSync()
return t, nil
}
// TailFile begins tailing the file. Output stream is made available
// via the `Tail.Lines` channel. To handle errors during tailing,
// invoke the `Wait` or `Err` method after finishing reading from the
// `Lines` channel.
func TailFile(filename string, config Config) (*Tail, error) {
if config.ReOpen && !config.Follow {
util.Fatal("cannot set ReOpen without Follow.")
}
t := &Tail{
Filename: filename,
Lines: make(chan *Line),
Config: config,
}
// when Logger was not specified in config, use default logger
if t.Logger == nil {
t.Logger = log.New(os.Stderr, "", log.LstdFlags)
}
if t.Poll {
t.watcher = watch.NewPollingFileWatcher(filename)
} else {
t.watcher = watch.NewInotifyFileWatcher(filename)
}
if t.MustExist {
var err error
t.file, err = OpenFile(t.Filename)
if err != nil {
return nil, err
}
}
go t.tailFileSync()
return t, nil
}
func NewTail(parser Parser, maxBackfill int64, path string, offsetPath string, offset int64) *Tail {
tail := new(Tail)
tail.Path = path
tail.offset = offset
tail.OffsetPath = offsetPath
tail.Parser = parser
tracker := watch.NewInotifyTracker()
w, err := tracker.NewWatcher()
if err != nil {
return nil
}
tail.Watcher = watch.NewInotifyFileWatcher(path, w)
tail.LoadOffset()
tail.maxBackfill = maxBackfill
handle, err := os.Open(path)
if err != nil {
logs.Debug("Can't open file: ", path)
return nil
} else {
tail.handle = handle
}
tail.seek()
return tail
}
