Get started on cmds module

1 files changed, 53 insertions, 0 deletions

diff --git a/cmds/cmds.go b/cmds/cmds.go
new file mode 100644
index 0000000..f61f2b8
--- /dev/null
+++ b/cmds/cmds.go
@@ -0,0 +1,53 @@
+package cmds
+
+import (
+	"errors"
+	"os"
+	"strings"
+)
+
+func Eval(cmd string) error {
+	args := strings.Split(cmd, " ")
+	switch args[0] {
+	case "cd":
+		if err := chDir(args); err != nil {
+			return err
+		}
+		break
+	case "export":
+		if err := export(args); err != nil {
+			return err
+		}
+		break
+	case "unset":
+		if len(args) == 1 || len(args) >= 3{
+			return errors.New("unset: usage: name")
+		}
+		os.Unsetenv(args[1])
+		break
+	case ":":
+		return nil
+	}
+	return nil
+}
+
+func chDir(args []string) error {
+	var dir string
+	if len(args) == 1 {
+		dir, _ = os.UserHomeDir()
+	} else {
+		dir = args[1]
+	}
+	return os.Chdir(dir)
+}
+
+func export(args []string) error {
+	if len(args) == 1 || len(args) >= 3 {
+		return errors.New("export: usage: name=value")
+	}
+	tmp := strings.Split(args[1], "=")
+	if len(tmp) != 2 {
+		return errors.New("export: usage: name=value")
+	}
+	return os.Setenv(tmp[0], tmp[1])
+}