Add 'environment' package

This commit adds a new environment package that manages all calls to the
underlying operating system.

pkg/environment/native_fs.go

@@ -0,0 +1,80 @@
+package environment
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+type Native struct{}
+
+func (Native) isEnv() {}
+
+func (Native) GetEnv(name string) string {
+	return os.Getenv(name)
+}
+
+func (Native) Stat(path string) (fs.FileInfo, error) {
+	return os.Stat(path)
+}
+
+func (Native) Lstat(path string) (fs.FileInfo, error) {
+	return os.Lstat(path)
+}
+
+func (Native) Readlink(path string) (string, error) {
+	return os.Readlink(path)
+}
+
+func (Native) Symlink(oldname, newname string) error {
+	return os.Symlink(oldname, newname)
+}
+
+func (Native) ReadDir(name string) ([]fs.DirEntry, error) {
+	return os.ReadDir(name)
+}
+
+func (Native) SameFile(f1, f2 fs.FileInfo) bool {
+	return os.SameFile(f1, f2)
+}
+
+func (Native) WalkDir(path string, f fs.WalkDirFunc) error {
+	return filepath.WalkDir(path, f)
+}
+
+func (Native) Executable() (string, error) {
+	return os.Executable() // TODO: not sure this works with the remote concepts
+}
+
+func (Native) Open(path string) (fs.File, error) {
+	return os.Open(path)
+}
+
+func (Native) Create(path string, mode fs.FileMode) (WritableFile, error) {
+	return os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, mode)
+}
+
+func (Native) Chtimes(name string, atime time.Time, mtime time.Time) error {
+	return os.Chtimes(name, atime, mtime)
+}
+
+func (Native) Mkdir(path string, mode fs.FileMode) error {
+	return os.Mkdir(path, mode)
+}
+
+func (Native) MkdirAll(path string, mode fs.FileMode) error {
+	return os.MkdirAll(path, mode)
+}
+
+func (Native) Remove(path string) error {
+	return os.Remove(path)
+}
+
+func (Native) RemoveAll(path string) error {
+	return os.RemoveAll(path)
+}
+
+func (Native) Abs(path string) (string, error) {
+	return filepath.Abs(path)
+}