filelogger to write output to a file

Makefile

@@ -6,21 +6,19 @@ install:
 	go install github.com/tendermint/tendermint/cmd/tendermint
 	go install github.com/tendermint/tendermint/cmd/barak
 	go install github.com/tendermint/tendermint/cmd/debora
+	go install github.com/tendermint/tendermint/cmd/filelogger
 
 build: 
 	go build -o build/tendermint github.com/tendermint/tendermint/cmd/tendermint
 	go build -o build/barak github.com/tendermint/tendermint/cmd/barak
 	go build -o build/debora github.com/tendermint/tendermint/cmd/debora
-
+	go build -o build/filelogger github.com/tendermint/tendermint/cmd/filelogger
-no_get: 
-	go build -o build/tendermint github.com/tendermint/tendermint/cmd/tendermint
-	go build -o build/barak github.com/tendermint/tendermint/cmd/barak
-	go build -o build/debora github.com/tendermint/tendermint/cmd/debora
 
 build_race: 
 	go build -race -o build/tendermint github.com/tendermint/tendermint/cmd/tendermint
 	go build -race -o build/barak github.com/tendermint/tendermint/cmd/barak
 	go build -race -o build/debora github.com/tendermint/tendermint/cmd/debora
+	go build -race -o build/filelogger github.com/tendermint/tendermint/cmd/filelogger
 
 test: build
 	go test github.com/tendermint/tendermint/...

binary/byteslice.go

@@ -1,14 +1,9 @@
 package binary
 
 import (
-	. "github.com/tendermint/tendermint/common"
 	"io"
 )
 
-const (
-	ByteSliceChunk = 1024
-)
-
 func WriteByteSlice(bz []byte, w io.Writer, n *int64, err *error) {
 	WriteVarint(len(bz), w, n, err)
 	WriteTo(bz, w, n, err)
@@ -24,16 +19,8 @@ func ReadByteSlice(r io.Reader, n *int64, err *error) []byte {
 		return nil
 	}
 
-	var buf, tmpBuf []byte
+	buf := make([]byte, length)
-	// read one ByteSliceChunk at a time and append
+	ReadFull(buf, r, n, err)
-	for i := 0; i*ByteSliceChunk < length; i++ {
-		tmpBuf = make([]byte, MinInt(ByteSliceChunk, length-i*ByteSliceChunk))
-		ReadFull(tmpBuf, r, n, err)
-		if *err != nil {
-			return nil
-		}
-		buf = append(buf, tmpBuf...)
-	}
 	return buf
 }
 

cmd/filelogger/README.md

@@ -0,0 +1,6 @@
+filelogger reads from stdin and writes to the specified file, in a way compatible for logrotate to move around.
+(see tendermint/common/os#AutoFile)
+
+```bash
+some_command arg1 arg2 2>&1 | filelogger -o path_to_log.log
+```

cmd/filelogger/main.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	. "github.com/tendermint/tendermint/common"
+)
+
+const Version = "0.0.1"
+const readBufferSize = 1024
+
+// Parse command-line options
+func parseFlags() (outpath string, version bool) {
+	flag.StringVar(&outpath, "outpath", "filelogger.out", "Output file name")
+	flag.BoolVar(&version, "version", false, "Version")
+	flag.Parse()
+	return
+}
+
+func main() {
+
+	// Read options
+	outpath, version := parseFlags()
+	if version {
+		fmt.Println(Fmt("filelogger version %v", Version))
+		return
+	}
+
+	outfile, err := OpenAutoFile(outpath)
+	if err != nil {
+		fmt.Println(Fmt("filelogger couldn't create outfile %v", outfile))
+		os.Exit(1)
+	}
+
+	go writeToOutfile(outfile)
+
+	// Trap signal
+	TrapSignal(func() {
+		outfile.Close()
+		fmt.Println("filelogger shutting down")
+	})
+}
+
+func writeToOutfile(outfile *AutoFile) {
+	// Forever, read from stdin and write to AutoFile.
+	buf := make([]byte, readBufferSize)
+	for {
+		n, err := os.Stdin.Read(buf)
+		outfile.Write(buf[:n])
+		if err != nil {
+			outfile.Close()
+			if err == io.EOF {
+				os.Exit(0)
+			} else {
+				fmt.Println("filelogger errored")
+				os.Exit(1)
+			}
+		}
+	}
+}

common/os.go

@@ -160,7 +160,6 @@ func (af *AutoFile) processTicks() {
 		if !ok {
 			return // Done.
 		}
-		fmt.Println("closeFile()")
 		af.mtx.Lock()
 		af.closeFile()
 		af.mtx.Unlock()
@@ -184,7 +183,6 @@ func (af *AutoFile) Write(b []byte) (n int, err error) {
 			return
 		}
 	}
-	fmt.Println("Write:", string(b))
 	return af.file.Write(b)
 }