From 3b79f6beb43b7e43b6d7f55b016a01a661b0ea7a Mon Sep 17 00:00:00 2001
From: aler9 <46489434+aler9@users.noreply.github.com>
Date: Sat, 19 Sep 2020 17:49:44 +0200
Subject: [PATCH] handle external commands with a dedicated struct

---
 client.go      | 17 ++++++-----------
 externalcmd.go | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 path.go        | 15 +++++----------
 utils.go       | 32 --------------------------------
 4 files changed, 60 insertions(+), 53 deletions(-)
 create mode 100644 externalcmd.go

diff --git a/client.go b/client.go
index 16611408..d3b2c93c 100644
--- a/client.go
+++ b/client.go
@@ -5,8 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"os"
-	"os/exec"
 	"strconv"
 	"strings"
 	"sync/atomic"
@@ -192,7 +190,7 @@ var errRunPlay = errors.New("play")
 var errRunRecord = errors.New("record")
 
 func (c *client) run() {
-	var onConnectCmd *exec.Cmd
+	var onConnectCmd *externalCmd
 	if c.p.conf.RunOnConnect != "" {
 		var err error
 		onConnectCmd, err = startExternalCommand(c.p.conf.RunOnConnect, "")
@@ -208,8 +206,7 @@ func (c *client) run() {
 	}
 
 	if onConnectCmd != nil {
-		onConnectCmd.Process.Signal(os.Interrupt)
-		onConnectCmd.Wait()
+		onConnectCmd.close()
 	}
 
 	close(c.describe)
@@ -886,7 +883,7 @@ func (c *client) runPlay() bool {
 		return "tracks"
 	}(), c.streamProtocol)
 
-	var onReadCmd *exec.Cmd
+	var onReadCmd *externalCmd
 	if c.path.conf.RunOnRead != "" {
 		var err error
 		onReadCmd, err = startExternalCommand(c.path.conf.RunOnRead, c.path.name)
@@ -902,8 +899,7 @@ func (c *client) runPlay() bool {
 	}
 
 	if onReadCmd != nil {
-		onReadCmd.Process.Signal(os.Interrupt)
-		onReadCmd.Wait()
+		onReadCmd.close()
 	}
 
 	return false
@@ -1037,7 +1033,7 @@ func (c *client) runRecord() bool {
 		return "tracks"
 	}(), c.streamProtocol)
 
-	var onPublishCmd *exec.Cmd
+	var onPublishCmd *externalCmd
 	if c.path.conf.RunOnPublish != "" {
 		var err error
 		onPublishCmd, err = startExternalCommand(c.path.conf.RunOnPublish, c.path.name)
@@ -1053,8 +1049,7 @@ func (c *client) runRecord() bool {
 	}
 
 	if onPublishCmd != nil {
-		onPublishCmd.Process.Signal(os.Interrupt)
-		onPublishCmd.Wait()
+		onPublishCmd.close()
 	}
 
 	return false
diff --git a/externalcmd.go b/externalcmd.go
new file mode 100644
index 00000000..660d05d6
--- /dev/null
+++ b/externalcmd.go
@@ -0,0 +1,49 @@
+package main
+
+import (
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+type externalCmd struct {
+	cmd *exec.Cmd
+}
+
+func startExternalCommand(cmdstr string, pathName string) (*externalCmd, error) {
+	var cmd *exec.Cmd
+	if runtime.GOOS == "windows" {
+		// in Windows the shell is not used and command is started directly
+		// variables are replaced manually in order to allow
+		// compatibility with linux commands
+		cmdstr = strings.ReplaceAll(cmdstr, "$RTSP_SERVER_PATH", pathName)
+		args := strings.Fields(cmdstr)
+		cmd = exec.Command(args[0], args[1:]...)
+
+	} else {
+		cmd = exec.Command("/bin/sh", "-c", "exec "+cmdstr)
+	}
+
+	// variables are available through environment variables
+	cmd.Env = append(os.Environ(),
+		"RTSP_SERVER_PATH="+pathName,
+	)
+
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	err := cmd.Start()
+	if err != nil {
+		return nil, err
+	}
+
+	return &externalCmd{
+		cmd: cmd,
+	}, nil
+}
+
+func (e *externalCmd) close() {
+	e.cmd.Process.Signal(os.Interrupt)
+	e.cmd.Wait()
+}
diff --git a/path.go b/path.go
index bd8db863..801ec14d 100644
--- a/path.go
+++ b/path.go
@@ -2,8 +2,6 @@ package main
 
 import (
 	"fmt"
-	"os"
-	"os/exec"
 	"time"
 )
 
@@ -29,8 +27,8 @@ type path struct {
 	publisherSdp           []byte
 	lastDescribeReq        time.Time
 	lastDescribeActivation time.Time
-	onInitCmd              *exec.Cmd
-	onDemandCmd            *exec.Cmd
+	onInitCmd              *externalCmd
+	onDemandCmd            *externalCmd
 }
 
 func newPath(p *program, name string, conf *pathConf) *path {
@@ -77,14 +75,12 @@ func (pa *path) onClose(wait bool) {
 
 	if pa.onInitCmd != nil {
 		pa.log("stopping on init command (closing)")
-		pa.onInitCmd.Process.Signal(os.Interrupt)
-		pa.onInitCmd.Wait()
+		pa.onInitCmd.close()
 	}
 
 	if pa.onDemandCmd != nil {
 		pa.log("stopping on demand command (closing)")
-		pa.onDemandCmd.Process.Signal(os.Interrupt)
-		pa.onDemandCmd.Wait()
+		pa.onDemandCmd.close()
 	}
 
 	for c := range pa.p.clients {
@@ -161,8 +157,7 @@ func (pa *path) onCheck() {
 		!pa.hasClientReaders() &&
 		time.Since(pa.lastDescribeReq) >= onDemandCmdStopAfterDescribeSecs {
 		pa.log("stopping on demand command (not requested anymore)")
-		pa.onDemandCmd.Process.Signal(os.Interrupt)
-		pa.onDemandCmd.Wait()
+		pa.onDemandCmd.close()
 		pa.onDemandCmd = nil
 	}
 
diff --git a/utils.go b/utils.go
index 23cc52d0..8a1fa00a 100644
--- a/utils.go
+++ b/utils.go
@@ -4,9 +4,7 @@ import (
 	"fmt"
 	"net"
 	"os"
-	"os/exec"
 	"regexp"
-	"runtime"
 	"strings"
 	"sync"
 
@@ -137,36 +135,6 @@ func checkPathName(name string) error {
 	return nil
 }
 
-func startExternalCommand(cmdstr string, pathName string) (*exec.Cmd, error) {
-	var cmd *exec.Cmd
-	if runtime.GOOS == "windows" {
-		// in Windows the shell is not used and command is started directly
-		// variables are replaced manually in order to allow
-		// compatibility with linux commands
-		cmdstr = strings.ReplaceAll(cmdstr, "$RTSP_SERVER_PATH", pathName)
-		args := strings.Fields(cmdstr)
-		cmd = exec.Command(args[0], args[1:]...)
-
-	} else {
-		cmd = exec.Command("/bin/sh", "-c", "exec "+cmdstr)
-	}
-
-	// variables are available through environment variables
-	cmd.Env = append(os.Environ(),
-		"RTSP_SERVER_PATH="+pathName,
-	)
-
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-
-	err := cmd.Start()
-	if err != nil {
-		return nil, err
-	}
-
-	return cmd, nil
-}
-
 func isBindError(err error) bool {
 	if nerr, ok := err.(*net.OpError); ok {
 		if serr, ok := nerr.Err.(*os.SyscallError); ok {