Adjust processing algorithm (issue #14)

 - Saves the given script/command in a temp file; and run the file
 - Avoid line break bytes exclusion, as well as the empty line scanned (if received)
 - In error case while sending report, the process continues buffering the chunk data until next threshold
 - When sending the last pending chunk and in a scanning context error; the chunk would include the error, which is concatenated to the previous chunk if available.
 	* At any case, the chunk has to contain bytes!

See #14

cmdpolling/continuousreport.go

@@ -4,6 +4,8 @@ import (
 	"bufio"
 	"errors"
 	"fmt"
+	"io/ioutil"
+	"os"
 	"os/exec"
 	"runtime"
 	"strings"
@@ -39,9 +41,9 @@ func cmdContinuousReportRun(c *cli.Context) error {
 	pollingSvc := cmd.WireUpPolling(c)
 
 	// cli command argument
-	var commandArg string
+	var cmdArg string
 	if c.Args().Present() {
-		commandArg = c.Args().First()
+		cmdArg = c.Args().First()
 	} else {
 		formatter.PrintFatal("argument missing", errors.New("a script or command is required"))
 	}
@@ -62,24 +64,44 @@ func cmdContinuousReportRun(c *cli.Context) error {
 	threshold := Threshold{lines: thresholdLines, time: thresholdTime, bytes: thresholdBytes}
 	log.Debug("Threshold", threshold)
 
-	if err := processCommand(pollingSvc, commandArg, threshold); err != nil {
+	if err := processCommand(pollingSvc, cmdArg, threshold); err != nil {
 		formatter.PrintFatal("cannot process continuous report command", err)
 	}
 
 	log.Info("completed")
 	return nil
 }
 
-func processCommand(pollingSvc *polling.PollingService, commandArg string, threshold Threshold) error {
+func processCommand(pollingSvc *polling.PollingService, cmdArg string, threshold Threshold) error {
 	log.Debug("processCommand")
 
+	// Saves script/command in a temp file
+	cmdFileName := strings.Join([]string{time.Now().Format("20060102150405"), "_", utils.RandomString(10)}, "")
+	if runtime.GOOS == "windows" {
+		cmdFileName = strings.Join([]string{cmdFileName, ".bat"}, "")
+	}
+
+	// Writes content
+	if err := ioutil.WriteFile(cmdFileName, []byte(cmdArg), 0600); err != nil {
+		log.Fatalf("Error creating temp file : ", err)
+	}
+
+	// Creates command
 	var newCmd *exec.Cmd
 	if runtime.GOOS == "windows" {
-		newCmd = exec.Command("cmd", "/C", commandArg)
+		newCmd = exec.Command("cmd", "/C", cmdFileName)
 	} else {
-		newCmd = exec.Command("/bin/sh", "-c", commandArg)
+		newCmd = exec.Command("/bin/sh", cmdFileName)
 	}
 
+	// Removes temp file
+	defer func() {
+		err := os.Remove(cmdFileName)
+		if err != nil {
+			log.Warn("Temp file cannot be removed", err.Error())
+		}
+	}()
+
 	// Gets the pipe command
 	stdout, err := newCmd.StdoutPipe()
 	if err != nil {
@@ -92,37 +114,36 @@ func processCommand(pollingSvc *polling.PollingService, commandArg string, thres
 		return fmt.Errorf("cannot start the specified command %v", err)
 	}
 
-	line := ""
+	chunk := ""
 	nLines, nTime, nBytes := 0, 0, 0
 	timeStart := time.Now()
 
 	scanner := bufio.NewScanner(bufio.NewReader(stdout))
 	for scanner.Scan() {
-		line += scanner.Text()
-		if len(line) > 0 {
-			nLines++
-			nTime = int(time.Now().Sub(timeStart).Seconds())
-			nBytes = len(line)
-			if nLines >= threshold.lines || nTime >= threshold.time || nBytes >= threshold.bytes {
-				if err := sendChunks(pollingSvc, line); err != nil {
-					return err
-				} else {
-					line = ""
-					nLines, nTime, nBytes = 0, 0, 0
-					timeStart = time.Now()
-				}
+		chunk = strings.Join([]string{chunk, scanner.Text(), "\n"}, "")
+		nLines++
+		nTime = int(time.Now().Sub(timeStart).Seconds())
+		nBytes = len(chunk)
+		if nLines >= threshold.lines || nTime >= threshold.time || nBytes >= threshold.bytes {
+			if err := sendChunks(pollingSvc, chunk); err != nil {
+				nLines, nTime = 0, 0
+				timeStart = time.Now()
+			} else {
+				chunk = ""
+				nLines, nTime, nBytes = 0, 0, 0
+				timeStart = time.Now()
 			}
 		}
 	}
 
 	if err := scanner.Err(); err != nil {
 		log.Error("==> Error: ", err.Error())
-		if err := sendChunks(pollingSvc, "error reading standard input:"+err.Error()); err != nil {
-			return err
-		}
-	} else {
+		chunk = strings.Join([]string{chunk, err.Error()}, "")
+	}
+
+	if len(chunk) > 0 {
 		log.Debug("Sending the last pending chunk")
-		if err := sendChunks(pollingSvc, line); err != nil {
+		if err := sendChunks(pollingSvc, chunk); err != nil {
 			return err
 		}
 	}

utils/utils.go

@@ -4,10 +4,12 @@ import (
 	"archive/zip"
 	"fmt"
 	"io"
+	"math/rand"
 	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
+	"time"
 
 	"github.com/codegangsta/cli"
 
@@ -186,3 +188,13 @@ func CheckRequiredFlags(c *cli.Context, flags []string) {
 		os.Exit(2)
 	}
 }
+
+func RandomString(strlen int) string {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	const chars = "abcdefghijklmnopqrstuvwxyz0123456789"
+	result := make([]byte, strlen)
+	for i := range result {
+		result[i] = chars[r.Intn(len(chars))]
+	}
+	return string(result)
+}