mv tmlibs files to libs dir

libs/cli/helper.go

@@ -0,0 +1,87 @@
+package cli
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+// WriteConfigVals writes a toml file with the given values.
+// It returns an error if writing was impossible.
+func WriteConfigVals(dir string, vals map[string]string) error {
+	data := ""
+	for k, v := range vals {
+		data = data + fmt.Sprintf("%s = \"%s\"\n", k, v)
+	}
+	cfile := filepath.Join(dir, "config.toml")
+	return ioutil.WriteFile(cfile, []byte(data), 0666)
+}
+
+// RunWithArgs executes the given command with the specified command line args
+// and environmental variables set. It returns any error returned from cmd.Execute()
+func RunWithArgs(cmd Executable, args []string, env map[string]string) error {
+	oargs := os.Args
+	oenv := map[string]string{}
+	// defer returns the environment back to normal
+	defer func() {
+		os.Args = oargs
+		for k, v := range oenv {
+			os.Setenv(k, v)
+		}
+	}()
+
+	// set the args and env how we want them
+	os.Args = args
+	for k, v := range env {
+		// backup old value if there, to restore at end
+		oenv[k] = os.Getenv(k)
+		err := os.Setenv(k, v)
+		if err != nil {
+			return err
+		}
+	}
+
+	// and finally run the command
+	return cmd.Execute()
+}
+
+// RunCaptureWithArgs executes the given command with the specified command
+// line args and environmental variables set. It returns string fields
+// representing output written to stdout and stderr, additionally any error
+// from cmd.Execute() is also returned
+func RunCaptureWithArgs(cmd Executable, args []string, env map[string]string) (stdout, stderr string, err error) {
+	oldout, olderr := os.Stdout, os.Stderr // keep backup of the real stdout
+	rOut, wOut, _ := os.Pipe()
+	rErr, wErr, _ := os.Pipe()
+	os.Stdout, os.Stderr = wOut, wErr
+	defer func() {
+		os.Stdout, os.Stderr = oldout, olderr // restoring the real stdout
+	}()
+
+	// copy the output in a separate goroutine so printing can't block indefinitely
+	copyStd := func(reader *os.File) *(chan string) {
+		stdC := make(chan string)
+		go func() {
+			var buf bytes.Buffer
+			// io.Copy will end when we call reader.Close() below
+			io.Copy(&buf, reader)
+			stdC <- buf.String()
+		}()
+		return &stdC
+	}
+	outC := copyStd(rOut)
+	errC := copyStd(rErr)
+
+	// now run the command
+	err = RunWithArgs(cmd, args, env)
+
+	// and grab the stdout to return
+	wOut.Close()
+	wErr.Close()
+	stdout = <-*outC
+	stderr = <-*errC
+	return stdout, stderr, err
+}