Merge pull request #1 from asymmetric-research/ignore-incomplete-lines

added IgnoreIncompleteLines option

cmd.go

@@ -177,6 +177,10 @@ type Options struct {
 	// value DEFAULT_LINE_BUFFER_SIZE is usually sufficient, but if
 	// ErrLineBufferOverflow errors occur, try increasing the size with this field.
 	LineBufferSize uint
+
+	// IgnoreIncompleteLines configures the 'ignoreIncompleteLines' option of the command's
+	// OutputStream's. If set to true, lines that do not end in '\n' are ignored.
+	IgnoreIncompleteLines bool
 }
 
 // NewCmdOptions creates a new Cmd with options. The command is not started
@@ -214,11 +218,11 @@ func NewCmdOptions(options Options, name string, args ...string) *Cmd {
 
 	if options.Streaming {
 		c.Stdout = make(chan string, DEFAULT_STREAM_CHAN_SIZE)
-		c.stdoutStream = NewOutputStream(c.Stdout)
+		c.stdoutStream = NewOutputStream(c.Stdout, options.IgnoreIncompleteLines)
 		c.stdoutStream.SetLineBufferSize(int(options.LineBufferSize))
 
 		c.Stderr = make(chan string, DEFAULT_STREAM_CHAN_SIZE)
-		c.stderrStream = NewOutputStream(c.Stderr)
+		c.stderrStream = NewOutputStream(c.Stderr, options.IgnoreIncompleteLines)
 		c.stderrStream.SetLineBufferSize(int(options.LineBufferSize))
 	}
 
@@ -682,22 +686,24 @@ func (e ErrLineBufferOverflow) Error() string {
 // While runnableCmd is running, lines are sent to the channel as soon as they
 // are written and newline-terminated by the command.
 type OutputStream struct {
-	streamChan chan string
-	bufSize    int
-	buf        []byte
-	lastChar   int
+	streamChan            chan string
+	bufSize               int
+	buf                   []byte
+	lastChar              int
+	ignoreIncompleteLines bool
 }
 
 // NewOutputStream creates a new streaming output on the given channel. The
 // caller must begin receiving on the channel before the command is started.
 // The OutputStream never closes the channel.
-func NewOutputStream(streamChan chan string) *OutputStream {
+func NewOutputStream(streamChan chan string, ignoreIncompleteLines bool) *OutputStream {
 	out := &OutputStream{
 		streamChan: streamChan,
 		// --
-		bufSize:  DEFAULT_LINE_BUFFER_SIZE,
-		buf:      make([]byte, DEFAULT_LINE_BUFFER_SIZE),
-		lastChar: 0,
+		bufSize:               DEFAULT_LINE_BUFFER_SIZE,
+		buf:                   make([]byte, DEFAULT_LINE_BUFFER_SIZE),
+		lastChar:              0,
+		ignoreIncompleteLines: ignoreIncompleteLines,
 	}
 	return out
 }
@@ -738,7 +744,13 @@ func (rw *OutputStream) Write(p []byte) (n int, err error) {
 		firstChar += newlineOffset + 1
 	}
 
+	// if the stream (p) does not end in a '\n', then we will have firstChar < n
 	if firstChar < n {
+		// if we are ignoring incomplete lines, then we can just exit here
+		if rw.ignoreIncompleteLines {
+			return // implicit
+		}
+
 		remain := len(p[firstChar:])
 		bufFree := len(rw.buf[rw.lastChar:])
 		if remain > bufFree {

cmd_test.go

@@ -12,7 +12,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-cmd/cmd"
+	"github.com/asymmetric-research/cmd"
 	"github.com/go-test/deep"
 )
 
@@ -752,7 +752,7 @@ func TestCmdOnlyStreamingOutput(t *testing.T) {
 
 func TestStreamingMultipleLines(t *testing.T) {
 	lines := make(chan string, 5)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 
 	// Quick side test: Lines() chan string should be the same chan string
 	// we created the object with
@@ -799,7 +799,7 @@ func TestStreamingMultipleLinesLastNotTerminated(t *testing.T) {
 	// If last line isn't \n terminated, go-cmd should flush it anyway
 	// https://github.com/go-cmd/cmd/pull/48
 	lines := make(chan string, 5)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 
 	// Quick side test: Lines() chan string should be the same chan string
 	// we created the object with
@@ -846,7 +846,7 @@ func TestStreamingMultipleLinesLastNotTerminated(t *testing.T) {
 
 func TestStreamingBlankLines(t *testing.T) {
 	lines := make(chan string, 5)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 
 	// Blank line in the middle
 	input := "foo\n\nbar\n"
@@ -924,7 +924,7 @@ LINES3:
 func TestStreamingCarriageReturn(t *testing.T) {
 	// Carriage return should be stripped
 	lines := make(chan string, 5)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 
 	input := "foo\r\nbar\r\n"
 	expectLines := []string{"foo", "bar"}
@@ -955,7 +955,7 @@ func TestStreamingLineBuffering(t *testing.T) {
 	// write. When line is later terminated with newline, we prepend the buffered
 	// line and send the complete line.
 	lines := make(chan string, 1)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 
 	// Write 3 unterminated lines. Without a newline, they'll be buffered until...
 	for i := 0; i < 3; i++ {
@@ -1018,7 +1018,7 @@ func TestStreamingErrLineBufferOverflow1(t *testing.T) {
 	longLine[cmd.DEFAULT_LINE_BUFFER_SIZE+1] = 'z'
 
 	lines := make(chan string, 5)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 
 	// Write the long line, it should only write (n) 3 bytes for "bc\n"
 	n, err := out.Write(longLine)
@@ -1079,7 +1079,7 @@ func TestStreamingErrLineBufferOverflow2(t *testing.T) {
 	// Overflow line buffer on 2nd write. So first write puts something in the
 	// buffer, and then 2nd overflows it instead of completing the line.
 	lines := make(chan string, 1)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 
 	// Get "bar" into the buffer by omitting its newline
 	input := "foo\nbar"
@@ -1143,7 +1143,7 @@ func TestStreamingSetLineBufferSize(t *testing.T) {
 	longLine[cmd.DEFAULT_LINE_BUFFER_SIZE+1] = '\n'
 
 	lines := make(chan string, 5)
-	out := cmd.NewOutputStream(lines)
+	out := cmd.NewOutputStream(lines, false)
 	out.SetLineBufferSize(cmd.DEFAULT_LINE_BUFFER_SIZE * 2)
 
 	n, err := out.Write(longLine)

cmd_windows_test.go

@@ -11,7 +11,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-cmd/cmd"
+	"github.com/asymmetric-research/cmd"
 	"github.com/go-test/deep"
 )
 

examples/blocking-buffered/main.go

@@ -3,7 +3,7 @@ package main
 import (
 	"fmt"
 
-	"github.com/go-cmd/cmd"
+	"github.com/asymmetric-research/cmd"
 )
 
 func main() {

examples/blocking-streaming/main.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/go-cmd/cmd"
+	"github.com/asymmetric-research/cmd"
 )
 
 func main() {

go.mod

@@ -1,4 +1,4 @@
-module github.com/go-cmd/cmd
+module github.com/asymmetric-research/cmd
 
 go 1.20