Logging to file.

logging/example/example.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/kisom/goutils/logging"
+	"github.com/kisom/testio"
+)
+
+var log = logging.Init()
+var olog = logging.New("subsystem #42", logging.LevelNotice)
+
+func main() {
+	exampleNewWriters()
+	log.Notice("Hello, world.")
+	log.Warning("this program is about to end")
+
+	olog.Print("now online")
+	logging.Suppress("olog")
+	olog.Print("extraneous information")
+
+	logging.Enable("olog")
+	olog.Print("relevant now")
+
+	logging.SuppressAll()
+	log.Alert("screaming into the void")
+	olog.Critical("can anyone hear me?")
+
+	log.Enable()
+	log.Notice("i'm baaack")
+	log.Suppress()
+	log.Warning("but not for long")
+
+	logging.EnableAll()
+	log.Notice("fare thee well")
+	olog.Print("all good journeys must come to an end")
+	exampleNewFromFile()
+}
+
+func exampleNewWriters() {
+	o := testio.NewBufCloser(nil)
+	e := testio.NewBufCloser(nil)
+
+	wlog := logging.NewFromWriters("writers", logging.DefaultLevel, o, e)
+	wlog.Notice("hello, world")
+	wlog.Notice("some more things happening")
+	wlog.Warning("something suspicious has happened")
+	wlog.Alert("pick up that can, Citizen!")
+
+	fmt.Println("--- BEGIN OUT ---")
+	fmt.Printf("%s", o.Bytes())
+	fmt.Println("--- END OUT ---")
+
+	fmt.Println("--- BEGIN ERR ---")
+	fmt.Printf("%s", e.Bytes())
+	fmt.Println("--- END ERR ---")
+}
+
+func exampleNewFromFile() {
+	flog, err := logging.NewFromFile("file logger", logging.LevelNotice,
+		"example.log", "example.err", true)
+	if err != nil {
+		log.Fatalf("failed to open logger: %v", err)
+	}
+	defer flog.Close()
+
+	flog.Notice("hello, world")
+	flog.Notice("some more things happening")
+	flog.Warning("something suspicious has happened")
+	flog.Alert("pick up that can, Citizen!")
+}

logging/log.go

@@ -124,20 +124,22 @@ func NewFromFile(domain string, level Level, outFile, errFile string, multiplex
 		level:  level,
 	}
 
-	var err error
+	outf, err := os.OpenFile(outFile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
-	l.out, err = os.OpenFile(outFile, os.O_APPEND|os.O_CREATE, 0644)
 	if err != nil {
 		return nil, err
 	}
 
-	l.err, err = os.OpenFile(errFile, os.O_APPEND|os.O_CREATE, 0644)
+	errf, err := os.OpenFile(errFile, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
 	if err != nil {
 		return nil, err
 	}
 
 	if multiplex {
-		l.out = mwc.MultiWriteCloser(l.out, os.Stdout)
+		l.out = mwc.MultiWriteCloser(outf, os.Stdout)
-		l.err = mwc.MultiWriteCloser(l.err, os.Stderr)
+		l.err = mwc.MultiWriteCloser(errf, os.Stderr)
+	} else {
+		l.out = outf
+		l.err = errf
 	}
 
 	Enable(domain)