Having Trouble Using anacrolix/log to Log to a File

[FIGBERT]

Starting from the default logger, it's pretty simple to discard all the logs:

config := torrent.NewDefaultClientConfig()
config.Logger = log.Default
config.Logger.Handlers = []log.Handler{log.DiscardHandler}

I can't quite get logging to a file to work, though:

if file, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0755); err == nil {
    handler := log.DefaultHandler
    handler.W = file
    config.Logger.Handlers = []log.Handler{handler}
}

[anacrolix]

Thanks I'll try this out and report back.

[FIGBERT]

Any updates?

[anacrolix]

Sorry for the delay, and the whacky log system. I was able to get it to work with a file, you still need to pass Debug=true in the ClientConfig, or set GO_LOG=namespace=debug (for example *, or client for how it's done in cmd/torrent, or some value that matches your logger's name).

diff --git a/cmd/torrent/download.go b/cmd/torrent/download.go
index 45164a3..ff25349 100644
--- a/cmd/torrent/download.go
+++ b/cmd/torrent/download.go
@@ -319,6 +319,13 @@ func downloadErr(flags downloadFlags) error {
 		if flags.Quiet {
 			logger = logger.FilterLevel(log.Critical)
 		}
+		file, err := os.OpenFile("client.log", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
+		if err != nil {
+			return fmt.Errorf("opening client log: %w", err)
+		}
+		handler := log.DefaultHandler
+		handler.W = file
+		logger.Handlers = []log.Handler{handler}
 		clientConfig.Logger = logger
 	}
 	if flags.RequireFastExtension {

[FIGBERT]

Wonderful. Wasn't setting Debug to true, and I really need to learn more about how to use file permission in Go (with regards to os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644).

Thanks for the help, as always.