[cbuild2cmake] Redirect error messages to stderr

cmd/cbuild2cmake/main.go

@@ -8,16 +8,19 @@ package main
 
 import (
 	"fmt"
+	"io"
 	"os"
 
 	"github.com/Open-CMSIS-Pack/cbuild2cmake/cmd/cbuild2cmake/commands"
 
 	log "github.com/sirupsen/logrus"
+	"github.com/sirupsen/logrus/hooks/writer"
 )
 
 func main() {
 	log.SetFormatter(new(LogFormatter))
-	log.SetOutput(os.Stdout)
+	log.SetOutput(io.Discard)
+	initLogHooks()
 
 	if len(version) == 0 {
 		version = "0.0.0-debug"
@@ -39,3 +42,22 @@ func (s *LogFormatter) Format(entry *log.Entry) ([]byte, error) {
 	msg := fmt.Sprintf("%s cbuild2cmake: %s\n", entry.Level.String(), entry.Message)
 	return []byte(msg), nil
 }
+
+func initLogHooks() {
+	log.AddHook(&writer.Hook{ // Send logs with level higher than warning to stderr
+		Writer: os.Stderr,
+		LogLevels: []log.Level{
+			log.PanicLevel,
+			log.FatalLevel,
+			log.ErrorLevel,
+			log.WarnLevel,
+		},
+	})
+	log.AddHook(&writer.Hook{ // Send info and debug logs to stdout
+		Writer: os.Stdout,
+		LogLevels: []log.Level{
+			log.InfoLevel,
+			log.DebugLevel,
+		},
+	})
+}