From d9b355f75ea694d1681b2319733957ec433cfa5f Mon Sep 17 00:00:00 2001
From: Nex <nex@nex.sx>
Date: Fri, 21 Oct 2016 13:16:22 +0200
Subject: [PATCH] Added proper piping of commands

---
 internal/common/common.go | 43 +++++++++++++++++++++++++++++++++++++++
 process/process_darwin.go | 14 ++++++++-----
 2 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/internal/common/common.go b/internal/common/common.go
index f0ea6dd..1cc26a1 100644
--- a/internal/common/common.go
+++ b/internal/common/common.go
@@ -341,3 +341,46 @@ func WaitTimeout(c *exec.Cmd, timeout time.Duration) error {
 		return ErrTimeout
 	}
 }
+
+// https://gist.github.com/kylelemons/1525278
+func Pipeline(cmds ...*exec.Cmd) (pipeLineOutput, collectedStandardError []byte, pipeLineError os.Error) {
+        // Require at least one command
+        if len(cmds) < 1 { 
+                return nil, nil, nil
+        }
+
+        // Collect the output from the command(s)
+        var output bytes.Buffer
+        var stderr bytes.Buffer
+
+        last := len(cmds) - 1
+        for i, cmd := range cmds[:last] {
+                var err os.Error
+                // Connect each command's stdin to the previous command's stdout
+                if cmds[i+1].Stdin, err = cmd.StdoutPipe(); err != nil {
+                        return nil, nil, err
+                }
+                // Connect each command's stderr to a buffer
+                cmd.Stderr = &stderr
+        }
+
+        // Connect the output and error for the last command
+        cmds[last].Stdout, cmds[last].Stderr = &output, &stderr
+
+        // Start each command
+        for _, cmd := range cmds {
+                if err := cmd.Start(); err != nil {
+                        return output.Bytes(), stderr.Bytes(), err
+                }
+        }
+
+        // Wait for each command to complete
+        for _, cmd := range cmds {
+                if err := cmd.Wait(); err != nil {
+                        return output.Bytes(), stderr.Bytes(), err
+                }
+        }
+
+        // Return the pipeline output and the collected standard error
+        return output.Bytes(), stderr.Bytes(), nil
+}
diff --git a/process/process_darwin.go b/process/process_darwin.go
index 37d878b..b061969 100644
--- a/process/process_darwin.go
+++ b/process/process_darwin.go
@@ -80,21 +80,25 @@ func (p *Process) Name() (string, error) {
 	return common.IntToString(k.Proc.P_comm[:]), nil
 }
 func (p *Process) Exe() (string, error) {
-	bin, err := exec.LookPath("lsof")
+	lsof_bin, err := exec.LookPath("lsof")
 	if err != nil {
 		return "", err
 	}
 
-	cmd := []string{"-p", strconv.Itoa(int(p.Pid)), "-Fn", "|", "awk", "NR==3{print}", "|", "sed",  "s/n\\//\\//"}
+	awk_bin, _ := exec.Lookpath("awk")
+	sed_bin, _ := exec.LookPath("sed")
 
-	fmt.Println(strings.Join(cmd, " "))
+	lsof := exec.Command(lsof_bin, "-p", strconv.Itoa(int(p.Pid)), "-Fn")
+	awk := exec.Command(awk_bin, "NR==3{print}")
+	sed := exec.Command("s/n\\//\\//")
+
+	output, stderr, err := common.Pipeline(lsof, awk, sed)
 
-	out, err := invoke.Command(bin, cmd...)
 	if err != nil {
 		return "", err
 	}
 
-	ret := strings.TrimSpace(string(out))
+	ret := strings.TrimSpace(string(output))
 
 	return ret, nil
 }