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mirror of https://github.com/rclone/rclone synced 2024-12-25 17:03:45 +01:00
rclone/fs/log/log.go
2018-08-26 17:20:38 +01:00

96 lines
2.3 KiB
Go

// Package log provides logging for rclone
package log
import (
"io"
"log"
"os"
"reflect"
"runtime"
"strings"
"github.com/ncw/rclone/fs"
"github.com/ncw/rclone/fs/config/flags"
)
// Flags
var (
logFile = flags.StringP("log-file", "", "", "Log everything to this file")
useSyslog = flags.BoolP("syslog", "", false, "Use Syslog for logging")
syslogFacility = flags.StringP("syslog-facility", "", "DAEMON", "Facility for syslog, eg KERN,USER,...")
)
// fnName returns the name of the calling +2 function
func fnName() string {
pc, _, _, ok := runtime.Caller(2)
name := "*Unknown*"
if ok {
name = runtime.FuncForPC(pc).Name()
dot := strings.LastIndex(name, ".")
if dot >= 0 {
name = name[dot+1:]
}
}
return name
}
// Trace debugs the entry and exit of the calling function
//
// It is designed to be used in a defer statement so it returns a
// function that logs the exit parameters.
//
// Any pointers in the exit function will be dereferenced
func Trace(o interface{}, format string, a ...interface{}) func(string, ...interface{}) {
if fs.Config.LogLevel < fs.LogLevelDebug {
return func(format string, a ...interface{}) {}
}
name := fnName()
fs.LogPrintf(fs.LogLevelDebug, o, name+": "+format, a...)
return func(format string, a ...interface{}) {
for i := range a {
// read the values of the pointed to items
typ := reflect.TypeOf(a[i])
if typ.Kind() == reflect.Ptr {
value := reflect.ValueOf(a[i])
if value.IsNil() {
a[i] = nil
} else {
pointedToValue := reflect.Indirect(value)
a[i] = pointedToValue.Interface()
}
}
}
fs.LogPrintf(fs.LogLevelDebug, o, ">"+name+": "+format, a...)
}
}
// InitLogging start the logging as per the command line flags
func InitLogging() {
// Log file output
if *logFile != "" {
f, err := os.OpenFile(*logFile, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0640)
if err != nil {
log.Fatalf("Failed to open log file: %v", err)
}
_, err = f.Seek(0, io.SeekEnd)
if err != nil {
fs.Errorf(nil, "Failed to seek log file to end: %v", err)
}
log.SetOutput(f)
redirectStderr(f)
}
// Syslog output
if *useSyslog {
if *logFile != "" {
log.Fatalf("Can't use --syslog and --log-file together")
}
startSysLog()
}
}
// Redirected returns true if the log has been redirected from stdout
func Redirected() bool {
return *useSyslog || *logFile != ""
}