1 files changed, 129 insertions, 0 deletions
diff --git a/filepath.go b/filepath.go
new file mode 100644
index 0000000..1817f58
--- /dev/null
+++ b/filepath.go
@@ -0,0 +1,129 @@
+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
+}
+
+// IsDir returns true when the given path is a directory
+func IsDir(path string) bool {
+	fi, err := os.Stat(path)
+	if err != nil {
+		return false
+	}
+
+	return fi.Mode().IsDir()
+}
+
+// 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 := ""
+		if v[1] == "EXEPATH" {
+			// Specific case to resolve $EXEPATH or ${EXEPATH} used as current executable path
+			val = GetExePath()
+
+		} else {
+			// Get env var value
+			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 normalizes a linux or windows like path
+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)
+}
+
+// GetUserHome returns the user's home directory or empty string on error
+func GetUserHome() string {
+	if usr, err := user.Current(); err == nil && usr != nil && usr.HomeDir != "" {
+		return usr.HomeDir
+	}
+	for _, p := range []string{"HOME", "HomePath"} {
+		if h := os.Getenv(p); h != "" {
+			return h
+		}
+	}
+
+	return ""
+}
+
+// GetExePath returns the full path of the current executable
+func GetExePath() string {
+	exePath := os.Args[0] // set fallback value
+	ee, _ := os.Executable()
+	exeAbsPath, err := filepath.Abs(ee)
+	if err == nil {
+		exePath, err = filepath.EvalSymlinks(exeAbsPath)
+		if err == nil {
+			exePath = filepath.Dir(ee)
+		} else {
+			exePath = filepath.Dir(exeAbsPath)
+		}
+	}
+	return exePath
+}