fix panic whan bash process never started

(e.g. because of 'argument list too long')

Author: brentp

CHANGES.md

@@ -1,3 +1,7 @@
+0.3.9
+=====
++ fix panic whan bash process never started (e.g. because of 'argument list too long')
+
 0.3.8
 =====
 + report time in log output

main.go

@@ -21,7 +21,7 @@ import (
 )
 
 // Version is the current version
-const Version = "0.3.8"
+const Version = "0.3.9"
 
 // ExitCode is the highest exit code seen in any command
 var ExitCode = 0
@@ -214,8 +214,11 @@ func run(args Params) {
 		if args.Verbose {
 			fmt.Fprintf(os.Stderr, "%s\n", p)
 		}
-		_, err := io.Copy(stdout, p)
-		check(err)
+		// reader can be nil if we couldn't even start the bash process
+		if p.Reader != nil {
+			_, err := io.Copy(stdout, p)
+			check(err)
+		}
 
 		p.Cleanup()
 		if t := time.Now(); t.After(last) {

process/process.go

@@ -71,12 +71,18 @@ func (c *Command) String() string {
 	if len(c.CmdStr) > 100 {
 		cmd = cmd[:80] + "..."
 	}
-	out, _ := c.Peek(20)
-	prompt := ", stdout[:20]: "
-	if len(out) < 20 {
-		prompt = "stdout: "
+	var prompt string
+	if c.Reader != nil {
+		out, _ := c.Peek(20)
+		prompt = ", stdout[:20]: "
+		if len(out) < 20 {
+			prompt = "stdout: "
+		}
+		prompt += fmt.Sprintf("'%s'", strings.Replace(string(out), "\n", "\\n", -1))
+	} else {
+		prompt = ", [no stdout]"
+
 	}
-	prompt += fmt.Sprintf("'%s'", strings.Replace(string(out), "\n", "\\n", -1))
 	errString := ""
 	if e := c.error(); e != "" {
 		errString = fmt.Sprintf(", error: %s", e)