From dfdb8f0c501379134039119f3aaa8d12358d86fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Paulo=20Sima=CC=83o?= <paulo@digitalcircle.com.br>
Date: Mon, 25 Oct 2021 18:44:30 -0300
Subject: [PATCH] Added parallel computing V2

---
 Readme.md   |  19 +++++----
 lib.go      | 116 +++++++++++++++++++++++++++++++++++++---------------
 lib_test.go |   2 +-
 3 files changed, 94 insertions(+), 43 deletions(-)

diff --git a/Readme.md b/Readme.md
index 24d9a5b..d8e0826 100644
--- a/Readme.md
+++ b/Readme.md
@@ -20,17 +20,20 @@ import "os"
 import "os/exec"
 
 func main() {
-	err := shelly.Exec(`
+	_, err := shelly.Exec(`
 	ls -larth &
 	pwd &
 	whoami
-	date`, &shelly.Opts{
-		Await: false,
-		SetupProc: func(cmd *exec.Cmd) {
-			cmd.Stdout = os.Stdout
-			cmd.Stderr = os.Stderr
-		},
-	})
+	date`,
+		&shelly.Opts{
+			Await: false,
+			Wd:    ".",
+			Debug: true,
+			SetupProc: func(cmd *exec.Cmd) {
+				cmd.Stdout = os.Stdout
+				cmd.Stderr = os.Stderr
+			},
+		})
 	if err != nil {
 		panic(err)
 	}
diff --git a/lib.go b/lib.go
index d5da228..e20117b 100644
--- a/lib.go
+++ b/lib.go
@@ -4,10 +4,11 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"os"
 	"os/exec"
+	"path/filepath"
 	"runtime"
 	"strings"
-	"sync"
 )
 
 type Mode int
@@ -40,13 +41,16 @@ const (
 	LINETYPE_SERIAL LineType = iota
 	LINETYPE_PARALLEL
 	LINETYPE_COMMENT
+	LINETYPE_CHANGEWD
 )
 
 // Opts tells Exec how to behave
 // Opts.Await will inform whether its call should wait for all parallel started jobs to finish
 // Opts.SetupProc will customize the processes before execution - Eg.: setting out and err
 type Opts struct {
+	Debug     bool
 	Await     bool
+	Wd        string
 	SetupProc func(cmd *exec.Cmd)
 }
 
@@ -158,28 +162,32 @@ func Lines(str string) ([]Line, error) {
 		Tokens: make([]string, 0),
 		LType:  LINETYPE_SERIAL,
 	}
+
+	addLine := func(line Line) {
+		if strings.HasPrefix(line.Tokens[0], "#") {
+			line.LType = LINETYPE_COMMENT
+		}
+
+		if line.Tokens[0] == "cd" {
+			line.LType = LINETYPE_CHANGEWD
+		}
+
+		ret = append(ret, line)
+	}
+
 	for _, tk := range tokens {
 		switch tk {
-		case "\n", ";":
+		case "\n", ";", "&&":
 			if len(line.Tokens) > 0 {
-				if strings.HasPrefix(line.Tokens[0], "#") {
-					line.LType = LINETYPE_COMMENT
-				} else {
-					line.LType = LINETYPE_SERIAL
-				}
-				ret = append(ret, line)
+				addLine(line)
 			}
 			line = Line{
 				Tokens: make([]string, 0),
 			}
 		case "&":
 			if len(line.Tokens) > 0 {
-				if strings.HasPrefix(line.Tokens[0], "#") {
-					line.LType = LINETYPE_COMMENT
-				} else {
-					line.LType = LINETYPE_PARALLEL
-				}
-				ret = append(ret, line)
+				line.LType = LINETYPE_PARALLEL
+				addLine(line)
 			}
 			line = Line{
 				Tokens: make([]string, 0),
@@ -189,15 +197,26 @@ func Lines(str string) ([]Line, error) {
 		}
 	}
 	if len(line.Tokens) > 0 {
-		ret = append(ret, line)
+		addLine(line)
 	}
 	return ret, nil
 }
 
 // Exec will call Lines and execute one by one
-func Exec(str string, opts ...*Opts) error {
+func Exec(str string, opts ...*Opts) ([]*exec.Cmd, error) {
+	wd, err := os.Getwd()
 
-	var opt *Opts
+	if err != nil {
+		return nil, err
+	}
+	ret := make([]*exec.Cmd, 0)
+	opt := &Opts{
+		Await: false,
+		Wd:    wd,
+		SetupProc: func(cmd *exec.Cmd) {
+
+		},
+	}
 	if opts != nil && len(opts) > 0 {
 		opt = opts[0]
 	}
@@ -208,47 +227,74 @@ func Exec(str string, opts ...*Opts) error {
 		}
 	}
 
+	cmdwd := opt.Wd
+
 	prepCmd := func(l Line) *exec.Cmd {
 		cmd := exec.Command(l.Tokens[0], l.Tokens[1:]...)
 		cmd.Stdout = log.Writer()
 		cmd.Stderr = log.Writer()
+		cmd.Dir = cmdwd
 		opt.SetupProc(cmd)
+		ret = append(ret, cmd)
 		return cmd
 	}
 
-	wg := sync.WaitGroup{}
 	lines, err := Lines(str)
 
 	if err != nil {
-		return err
+		return ret, err
 	}
 	for _, l := range lines {
 
 		switch l.LType {
 		case LINETYPE_COMMENT:
 			continue
+		case LINETYPE_CHANGEWD:
+
+			if filepath.IsAbs(l.Tokens[1]) {
+				cmdwd = l.Tokens[1]
+			} else {
+				cmdwd, err = filepath.Abs(filepath.Join(wd, l.Tokens[1]))
+				if err != nil {
+					return nil, err
+				}
+			}
+			log.Printf("CMDWD NOW IS: %s", cmdwd)
+			continue
 		case LINETYPE_SERIAL:
 			cmd := prepCmd(l)
+			if opt.Debug {
+				log.Printf("Running %s from dir %s with params %v", cmd.Path, cmd.Dir, cmd.Args)
+			}
 			err = cmd.Run()
+			if opt.Debug {
+				if err != nil {
+					log.Printf("Error running: %s: %s", cmd.Path, err.Error())
+				}
+			}
 			if err != nil {
-				return err
+				return ret, err
 			}
 		case LINETYPE_PARALLEL:
-			go func(l Line) {
-				cmd := prepCmd(l)
-				wg.Add(1)
-				err = cmd.Run()
-				wg.Done()
-			}(l)
+			cmd := prepCmd(l)
+
+			if opt.Debug {
+				log.Printf("Running %s from dir %s with params %v", cmd.Path, cmd.Dir, cmd.Args)
+			}
+			err = cmd.Start()
+			if opt.Debug {
+				if err != nil {
+					log.Printf("Error running: %s: %s", cmd.Path, err.Error())
+				}
+			}
+			if err != nil {
+				return nil, err
+			}
+
 		}
-
 	}
 
-	if opt.Await {
-		wg.Wait()
-	}
-
-	return nil
+	return ret, err
 
 }
 
@@ -256,9 +302,11 @@ func Exec(str string, opts ...*Opts) error {
 func Kill(p int) error {
 	switch runtime.GOOS {
 	case "windows":
-		return Exec(fmt.Sprintf("taskkill /T /F /PID %d", p))
+		_, err := Exec(fmt.Sprintf("taskkill /T /F /PID %d", p))
+		return err
 	default:
-		return Exec(fmt.Sprintf("kill -9 %d", p))
+		_, err := Exec(fmt.Sprintf("kill -9 %d", p))
+		return err
 
 	}
 }
diff --git a/lib_test.go b/lib_test.go
index e9964a2..f4a96f3 100644
--- a/lib_test.go
+++ b/lib_test.go
@@ -27,7 +27,7 @@ func TestLines(t *testing.T) {
 }
 
 func TestExec(t *testing.T) {
-	err := Exec(`
+	_, err := Exec(`
 	ls -larth &
 	pwd &
 	whoami &