Add command file to handle os.Exec related functions

2 files changed, 49 insertions, 2 deletions

diff --git a/command.go b/command.go
new file mode 100644
index 0000000..009f620
--- /dev/null
+++ b/command.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+	"bytes"
+	"os/exec"
+	"syscall"
+)
+
+// RunCommand runs the given command with arguemtns and returns the output
+// Refer to https://stackoverflow.com/questions/10385551/get-exit-code-go
+func RunCommand(name string, dir string, args ...string) (stdout string, stderr string, exitCode int) {
+	var outbuf, errbuf bytes.Buffer
+	cmd := exec.Command(name, args...)
+	cmd.Dir = dir
+	cmd.Stdout = &outbuf
+	cmd.Stderr = &errbuf
+
+	err := cmd.Run()
+	stdout = outbuf.String()
+	stderr = errbuf.String()
+
+	if err != nil {
+		// try to get the exit code
+		if exitError, ok := err.(*exec.ExitError); ok {
+			ws := exitError.Sys().(syscall.WaitStatus)
+			exitCode = ws.ExitStatus()
+		} else {
+			// This will happen (in OSX) if `name` is not available in $PATH,
+			// in this situation, exit code could not be get, and stderr will be
+			// empty string very likely, so we use the default fail code, and format err
+			// to string and set to stderr
+			exitCode = 1
+			if stderr == "" {
+				stderr = err.Error()
+			}
+		}
+	} else {
+		// success, exitCode should be 0 if go is ok
+		ws := cmd.ProcessState.Sys().(syscall.WaitStatus)
+		exitCode = ws.ExitStatus()
+	}
+	return
+}
diff --git a/git.go b/git.go
index 6f4cc99..009f620 100644
--- a/git.go
+++ b/git.go
@@ -6,13 +6,17 @@ import (
 	"syscall"
 )
 
-func RunCommand(name string, dir string, args ...string) (stderr string, exitCode int) {
-	var errbuf bytes.Buffer
+// RunCommand runs the given command with arguemtns and returns the output
+// Refer to https://stackoverflow.com/questions/10385551/get-exit-code-go
+func RunCommand(name string, dir string, args ...string) (stdout string, stderr string, exitCode int) {
+	var outbuf, errbuf bytes.Buffer
 	cmd := exec.Command(name, args...)
 	cmd.Dir = dir
+	cmd.Stdout = &outbuf
 	cmd.Stderr = &errbuf
 
 	err := cmd.Run()
+	stdout = outbuf.String()
 	stderr = errbuf.String()
 
 	if err != nil {