Initial commit to add golib

Signed-off-by: Sebastien Douheret <sebastien.douheret@iot.bzh>

1 files changed, 81 insertions, 0 deletions

diff --git a/golib/filepath.go b/golib/filepath.go
new file mode 100644
index 0000000..5a923b4
--- /dev/null
+++ b/golib/filepath.go
@@ -0,0 +1,81 @@
+package common
+
+import (
+	"fmt"
+	"os"
+	"os/user"
+	"path"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
+)
+
+// Exists returns whether the given file or directory exists or not
+func Exists(path string) bool {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true
+	}
+	if os.IsNotExist(err) {
+		return false
+	}
+	return true
+}
+
+// ResolveEnvVar Resolved environment variable regarding the syntax ${MYVAR}
+// or $MYVAR following by a slash or a backslash
+func ResolveEnvVar(s string) (string, error) {
+	if s == "" {
+		return s, nil
+	}
+
+	// Resolved tilde : ~/
+	if len(s) > 2 && s[:2] == "~/" {
+		if usr, err := user.Current(); err == nil {
+			s = filepath.Join(usr.HomeDir, s[2:])
+		}
+	}
+
+	// Resolved ${MYVAR}
+	re := regexp.MustCompile("\\${([^}]+)}")
+	vars := re.FindAllStringSubmatch(s, -1)
+	res := s
+	for _, v := range vars {
+		val := os.Getenv(v[1])
+		if val == "" {
+			// Specific case to resolved $HOME or ${HOME} on Windows host
+			if runtime.GOOS == "windows" && v[1] == "HOME" {
+				if usr, err := user.Current(); err == nil {
+					val = usr.HomeDir
+				}
+			} else {
+				return res, fmt.Errorf("ERROR: %s env variable not defined", v[1])
+			}
+		}
+
+		rer := regexp.MustCompile("\\${" + v[1] + "}")
+		res = rer.ReplaceAllString(res, val)
+	}
+
+	// Resolved $MYVAR following by a slash (or a backslash for Windows)
+	// TODO
+	//re := regexp.MustCompile("\\$([^\\/])+/")
+
+	return path.Clean(res), nil
+}
+
+// PathNormalize
+func PathNormalize(p string) string {
+	sep := string(filepath.Separator)
+	if sep != "/" {
+		return p
+	}
+	// Replace drive like C: by C/
+	res := p
+	if p[1:2] == ":" {
+		res = p[0:1] + sep + p[2:]
+	}
+	res = strings.Replace(res, "\\", "/", -1)
+	return filepath.Clean(res)
+}