oops. had the binary

Signed-off-by: Jeff Carr <jcarr@wit.com>

.gitignore

@@ -0,0 +1 @@
+example1/example1

example1/Makefile

@@ -0,0 +1,3 @@
+all:
+	go build
+	./example1

example1/main.go

@@ -0,0 +1,44 @@
+package main
+
+/*
+import "log"
+import "reflect"
+*/
+
+import "os"
+
+// import "github.com/davecgh/go-spew/spew"
+
+import "git.wit.com/wit/shell"
+
+func main() {
+
+	shell.Run("ls /tmp")
+
+	shell.Run("ping -c 3 localhost")
+
+	// slow down the polling to every 2 seconds
+	shell.SetDelayInMsec(2000)
+
+	shell.Run("ping -c 4 localhost")
+
+	// capture ping output into a file
+	fout, _ := os.Create("/tmp/example1.ping.stdout")
+	ferr, _ := os.Create("/tmp/example1.ping.stderr")
+	shell.SetStdout(fout)
+	shell.SetStderr(ferr)
+
+	shell.Run("ping -c 5 localhost")
+
+	// turn out process exit debugging
+	shell.SpewOn()
+
+	fout, _ = os.Create("/tmp/example1.fail.stdout")
+	ferr, _ = os.Create("/tmp/example1.fail.stderr")
+	shell.SetStdout(fout)
+	shell.SetStderr(ferr)
+
+	// TODO: this might not be working
+	// check error handling
+	shell.Run("ls /tmpthisisnothere")
+}

shell.go

@@ -1,7 +1,6 @@
 package shell
 
-import "fmt"
+// import "log"
-import "log"
 import "strings"
 import "time"
 import "os"
@@ -10,19 +9,50 @@ import "bufio"
 import "github.com/davecgh/go-spew/spew"
 import "github.com/svent/go-nbreader"
 
+import log "github.com/sirupsen/logrus"
+// import "github.com/wercker/journalhook"
+
+var shellStdout *os.File
+var shellStderr *os.File
+
+var spewOn bool = false
+var msecDelay int = 20	// number of milliseconds to delay between reads with no data
+
 func Script(cmds string) int {
 	// split on new lines (while we are at it, handle stupid windows text files
 	lines := strings.Split(strings.Replace(cmds, "\r\n", "\n", -1), "\n")
 
 	for _, line := range lines {
 		line = strings.TrimSpace(line) // this is like 'chomp' in perl
-		fmt.Println("LINE:", line)
+		log.Println("LINE:", line)
 		time.Sleep(1)
 		Run(line)
 	}
 	return 0
 }
 
+/*
+func UseJournalctl() {
+	journalhook.Enable()
+}
+*/
+
+func SpewOn() {
+	spewOn = true
+}
+
+func SetDelayInMsec(msecs int) {
+	msecDelay = msecs
+}
+
+func SetStdout(newout *os.File) {
+	shellStdout = newout
+}
+
+func SetStderr(newerr *os.File) {
+	shellStderr = newerr
+}
+
 func Run(cmdline string) int {
 	log.Println("START " + cmdline)
 
@@ -42,71 +72,74 @@ func Run(cmdline string) int {
 	}
 
 	process := exec.Command(cmdArgs[0], cmdArgs[1:len(cmdArgs)]...)
-	stdout, _ := process.StdoutPipe()
+	pstdout, _ := process.StdoutPipe()
-	stderr, _ := process.StderrPipe()
+	pstderr, _ := process.StderrPipe()
+
+	if (spewOn) {
+		spew.Dump(pstdout)
+	}
+
 	process.Start()
 
-	f := bufio.NewWriter(os.Stdout)
+	if (shellStdout == nil) {
+		shellStdout = os.Stdout
+	}
 
-	newreader := bufio.NewReader(stdout)
+	f := bufio.NewWriter(shellStdout)
+
+	newreader := bufio.NewReader(pstdout)
 	nbr := nbreader.NewNBReader(newreader, 1024)
 
-	newerrreader := bufio.NewReader(stderr)
+	tmp := bufio.NewReader(pstderr)
-	nbrerr := nbreader.NewNBReader(newerrreader, 1024)
+	go NonBlockingReader(tmp, shellStderr)
 
-	for {
+	totalCount := 0
-		time.Sleep(2 * time.Millisecond)   // only check the buffer 500 times a second
+
+	var dead bool = false
+	for (dead == false) {
+		time.Sleep(time.Duration(msecDelay) * time.Millisecond)   // only check the buffer 500 times a second
 		// log.Println("sleep done")
 
+		var empty bool = false
+		// tight loop that reads 1K at a time until buffer is empty
+		for (empty == false) {
 			oneByte := make([]byte, 1024)
 			count, err := nbr.Read(oneByte)
+			totalCount += count
 
 			if (err != nil) {
-			// log.Println("Read() count = ", count, "err = ", err)
+				log.Println("Read() count = ", count, "err = ", err)
 				oneByte = make([]byte, 1024)
 				count, err = nbr.Read(oneByte)
-			f.Write([]byte(string(oneByte)))
+				log.Println("STDOUT: count = ", count)
+				f.Write(oneByte[0:count])
 				f.Flush()
+				empty = true
+				dead = true
 			}
-		f.Write([]byte(string(oneByte)))
+			// f.Write([]byte(string(oneByte)))
-		f.Flush()
+			if (count == 0) {
-
+				empty = true
-		oneByte = make([]byte, 1024)
-		count, err = nbrerr.Read(oneByte)
-
-		if (err != nil) {
-			oneByte = make([]byte, 1024)
-			count, err = nbrerr.Read(oneByte)
-			f.Write([]byte(string(oneByte)))
-			f.Flush()
-
-			log.Println("Read() count = ", count, "err = ", err)
-			spew.Dump(process.Process)
-			spew.Dump(process.ProcessState)
-			err := process.Wait()
-			if err != nil {
-				spew.Dump(err.(*exec.ExitError))
-				spew.Dump(process.ProcessState)
-				stuff := err.(*exec.ExitError)
-				log.Println("ERROR ", stuff)
-				log.Println("END   ", cmdline)
-				return -1
-			}
-			log.Println("END   ", cmdline)
-			return 0
 			} else {
-			f.Write([]byte(string(oneByte)))
+				log.Println("STDOUT: count = ", count)
+				f.Write(oneByte[0:count])
 				f.Flush()
 			}
+		}
 
-		// spew.Dump(reflect.ValueOf(cmd.Process).Elem())
+		if (totalCount != 0) {
+			log.Println("STDOUT: totalCount = ", totalCount)
+			totalCount = 0
+		}
 	}
 
 	err := process.Wait()
 
 	if err != nil {
+		if (spewOn) {
 			spew.Dump(err.(*exec.ExitError))
 			spew.Dump(process.ProcessState)
+		}
 		stuff := err.(*exec.ExitError)
 		log.Println("ERROR ", stuff)
 		log.Println("END   ", cmdline)
@@ -122,3 +155,37 @@ func Daemon(cmdline string, timeout time.Duration) int {
 		time.Sleep(timeout)
 	}
 }
+
+// pass in two file handles (1 read, 1 write)
+func NonBlockingReader(buffReader *bufio.Reader, writeFileHandle *os.File) {
+	// newreader := bufio.NewReader(readFileHandle)
+
+	// create a nonblocking GO reader
+        nbr := nbreader.NewNBReader(buffReader, 1024)
+
+	for {
+		// defer buffReader.Close()
+		// defer writeFileHandle.Flush()
+		defer writeFileHandle.Close()
+		totalCount := 0
+		for {
+			oneByte := make([]byte, 1024)
+			count, err := nbr.Read(oneByte)
+			if (err != nil) {
+				log.Println("count, err =", count, err)
+				return
+			}
+			totalCount += count
+			if (count == 0) {
+				time.Sleep(time.Duration(msecDelay) * time.Millisecond)   // without this delay this will peg the CPU
+				if (totalCount != 0) {
+					log.Println("STDERR: totalCount = ", totalCount)
+					totalCount = 0
+				}
+			} else {
+				log.Println("STDERR: count = ", count)
+				writeFileHandle.Write(oneByte[0:count])
+			}
+		}
+	}
+}