refactor towards new cli.Interface

1 files changed, 63 insertions, 0 deletions

diff --git a/pkg/cli/command.go b/pkg/cli/command.go
new file mode 100644
index 0000000..5b3ded5
--- /dev/null
+++ b/pkg/cli/command.go
@@ -0,0 +1,63 @@
+/*******************************************************************************
+*
+* Copyright 2017 Stefan Majewsky <majewsky@gmx.net>
+*
+* This program is free software: you can redistribute it and/or modify it under
+* the terms of the GNU General Public License as published by the Free Software
+* Foundation, either version 3 of the License, or (at your option) any later
+* version.
+*
+* This program is distributed in the hope that it will be useful, but WITHOUT ANY
+* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License along with
+* this program. If not, see <http://www.gnu.org/licenses/>.
+*
+*******************************************************************************/
+
+package cli
+
+import (
+	"fmt"
+	"io"
+	"os/exec"
+	"strings"
+)
+
+//Command describes a command that can be run using the methods in the
+//Interface interface.
+type Command struct {
+	Program []string
+	WorkDir string
+}
+
+type commandError struct {
+	Cmd Command
+	Err error
+}
+
+func (e commandError) Error() string {
+	cmdline := strings.Join(e.Cmd.Program, " ")
+	if e.Cmd.WorkDir == "" {
+		return fmt.Sprintf("exec `%s`: %s",
+			cmdline, e.Err.Error(),
+		)
+	}
+	return fmt.Sprintf("exec `%s` in %s: %s",
+		cmdline, e.Cmd.WorkDir, e.Err.Error(),
+	)
+}
+
+func (c Command) run(stdout, stderr io.Writer) error {
+	cmd := exec.Command(c.Program[0], c.Program[1:]...)
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	cmd.Dir = c.WorkDir
+
+	err := cmd.Run()
+	if err != nil {
+		err = commandError{c, err}
+	}
+	return err
+}