fs/log: don't compile systemd log integration for non unix systems

fs/log/systemd_unix.go

@@ -0,0 +1,50 @@
+// Systemd interface for Unix variants only
+
+// +build !windows,!nacl,!plan9
+
+package log
+
+import (
+	"fmt"
+	"log"
+	"strings"
+
+	sysdjournald "github.com/iguanesolutions/go-systemd/v5/journald"
+	"github.com/rclone/rclone/fs"
+)
+
+// Enables systemd logs if configured or if auto detected
+func startSystemdLog() bool {
+	flagsStr := "," + Opt.Format + ","
+	var flags int
+	if strings.Contains(flagsStr, ",longfile,") {
+		flags |= log.Llongfile
+	}
+	if strings.Contains(flagsStr, ",shortfile,") {
+		flags |= log.Lshortfile
+	}
+	log.SetFlags(flags)
+	fs.LogPrint = func(level fs.LogLevel, text string) {
+		text = fmt.Sprintf("%s%-6s: %s", systemdLogPrefix(level), level, text)
+		_ = log.Output(4, text)
+	}
+	return true
+}
+
+var logLevelToSystemdPrefix = []string{
+	fs.LogLevelEmergency: sysdjournald.EmergPrefix,
+	fs.LogLevelAlert:     sysdjournald.AlertPrefix,
+	fs.LogLevelCritical:  sysdjournald.CritPrefix,
+	fs.LogLevelError:     sysdjournald.ErrPrefix,
+	fs.LogLevelWarning:   sysdjournald.WarningPrefix,
+	fs.LogLevelNotice:    sysdjournald.NoticePrefix,
+	fs.LogLevelInfo:      sysdjournald.InfoPrefix,
+	fs.LogLevelDebug:     sysdjournald.DebugPrefix,
+}
+
+func systemdLogPrefix(l fs.LogLevel) string {
+	if l >= fs.LogLevel(len(logLevelToSystemdPrefix)) {
+		return ""
+	}
+	return logLevelToSystemdPrefix[l]
+}