1 files changed, 120 insertions, 0 deletions
diff --git a/main/civisibility/utils/home.go b/main/civisibility/utils/home.go
new file mode 100644
index 0000000..8625010
--- /dev/null
+++ b/main/civisibility/utils/home.go
@@ -0,0 +1,120 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2024 Datadog, Inc.
+
+package utils
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+// This code is based on: https://github.com/mitchellh/go-homedir/blob/v1.1.0/homedir.go (MIT License)
+
+// ExpandPath expands a file path that starts with '~' to the user's home directory.
+// If the path does not start with '~', it is returned unchanged.
+//
+// Parameters:
+//
+//	path - The file path to be expanded.
+//
+// Returns:
+//
+//	The expanded file path, with '~' replaced by the user's home directory, if applicable.
+func ExpandPath(path string) string {
+	if len(path) == 0 || path[0] != '~' {
+		return path
+	}
+
+	// If the second character is not '/' or '\', return the path unchanged
+	if len(path) > 1 && path[1] != '/' && path[1] != '\\' {
+		return path
+	}
+
+	homeFolder := getHomeDir()
+	if len(homeFolder) > 0 {
+		return filepath.Join(homeFolder, path[1:])
+	}
+
+	return path
+}
+
+// getHomeDir returns the home directory of the current user.
+// The method used to determine the home directory depends on the operating system.
+//
+// On Windows, it prefers the HOME environment variable, then USERPROFILE, and finally combines HOMEDRIVE and HOMEPATH.
+// On Unix-like systems, it prefers the HOME environment variable, and falls back to various shell commands
+// to determine the home directory if necessary.
+//
+// Returns:
+//
+//	The home directory of the current user.
+func getHomeDir() string {
+	if runtime.GOOS == "windows" {
+		if home := os.Getenv("HOME"); home != "" {
+			// First prefer the HOME environment variable
+			return home
+		}
+		if userProfile := os.Getenv("USERPROFILE"); userProfile != "" {
+			// Prefer the USERPROFILE environment variable
+			return userProfile
+		}
+
+		homeDrive := os.Getenv("HOMEDRIVE")
+		homePath := os.Getenv("HOMEPATH")
+		return homeDrive + homePath
+	}
+
+	homeEnv := "HOME"
+	if runtime.GOOS == "plan9" {
+		// On plan9, environment variables are lowercase.
+		homeEnv = "home"
+	}
+
+	if home := os.Getenv(homeEnv); home != "" {
+		// Prefer the HOME environment variable
+		return home
+	}
+
+	var stdout bytes.Buffer
+	if runtime.GOOS == "darwin" {
+		// On macOS, use dscl to read the NFSHomeDirectory
+		cmd := exec.Command("sh", "-c", `dscl -q . -read /Users/"$(whoami)" NFSHomeDirectory | sed 's/^[^ ]*: //'`)
+		cmd.Stdout = &stdout
+		if err := cmd.Run(); err == nil {
+			result := strings.TrimSpace(stdout.String())
+			if result != "" {
+				return result
+			}
+		}
+	} else {
+		// On other Unix-like systems, use getent to read the passwd entry for the current user
+		cmd := exec.Command("getent", "passwd", strconv.Itoa(os.Getuid()))
+		cmd.Stdout = &stdout
+		if err := cmd.Run(); err == nil {
+			if passwd := strings.TrimSpace(stdout.String()); passwd != "" {
+				// The passwd entry is in the format: username:password:uid:gid:gecos:home:shell
+				passwdParts := strings.SplitN(passwd, ":", 7)
+				if len(passwdParts) > 5 {
+					return passwdParts[5]
+				}
+			}
+		}
+	}
+
+	// If all else fails, use the shell to determine the home directory
+	stdout.Reset()
+	cmd := exec.Command("sh", "-c", "cd && pwd")
+	cmd.Stdout = &stdout
+	if err := cmd.Run(); err == nil {
+		return strings.TrimSpace(stdout.String())
+	}
+
+	return ""
+}