btcd/btcutil/appdata.go
Dawid Ciężarkiewicz bff8d9dfd2
fix: use HOME dir if set
HOME directory should be preferred source of home directory information.

It's a common pattern to run software with a custom HOME to temporarily isolate it from the system-set home directory. All Unix software I ever worked with would respect HOME.

Preferring `user.Current()` (which I guess reads from `/etc/passwd`) make it impossible to temporarily change effective home, as changing `/etc/passwd` is not an option.

I'm currently migrating things to a self-hosted github-actions runner, where one system user is used for all github actions runners, but each instance gets a different `HOME`, and is otherwise sandboxed to not even have permissions to touch the original home. Everything works except `lncli` which fails with:

```
[lncli] could not load global options: could not read profile file /home/github-runner/.lncli/profiles.json: could not load profile file /home/github-runner/.lncli/profiles.json: open /home/github-runner/.lncli/profiles.json: permission denied
```

and I traced it to this code.
2024-04-23 22:06:46 -07:00

102 lines
3.2 KiB
Go

// Copyright (c) 2013-2017 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package btcutil
import (
"os"
"os/user"
"path/filepath"
"runtime"
"strings"
"unicode"
)
// appDataDir returns an operating system specific directory to be used for
// storing application data for an application. See AppDataDir for more
// details. This unexported version takes an operating system argument
// primarily to enable the testing package to properly test the function by
// forcing an operating system that is not the currently one.
func appDataDir(goos, appName string, roaming bool) string {
if appName == "" || appName == "." {
return "."
}
// The caller really shouldn't prepend the appName with a period, but
// if they do, handle it gracefully by trimming it.
appName = strings.TrimPrefix(appName, ".")
appNameUpper := string(unicode.ToUpper(rune(appName[0]))) + appName[1:]
appNameLower := string(unicode.ToLower(rune(appName[0]))) + appName[1:]
var homeDir string
// If HOME is set, use it
homeDir = os.Getenv("HOME")
// If not, Get the OS specific home directory via the Go standard lib.
usr, err := user.Current()
if err != nil || homeDir == "" {
homeDir = usr.HomeDir
}
switch goos {
// Attempt to use the LOCALAPPDATA or APPDATA environment variable on
// Windows.
case "windows":
// Windows XP and before didn't have a LOCALAPPDATA, so fallback
// to regular APPDATA when LOCALAPPDATA is not set.
appData := os.Getenv("LOCALAPPDATA")
if roaming || appData == "" {
appData = os.Getenv("APPDATA")
}
if appData != "" {
return filepath.Join(appData, appNameUpper)
}
case "darwin":
if homeDir != "" {
return filepath.Join(homeDir, "Library",
"Application Support", appNameUpper)
}
case "plan9":
if homeDir != "" {
return filepath.Join(homeDir, appNameLower)
}
default:
if homeDir != "" {
return filepath.Join(homeDir, "."+appNameLower)
}
}
// Fall back to the current directory if all else fails.
return "."
}
// AppDataDir returns an operating system specific directory to be used for
// storing application data for an application.
//
// The appName parameter is the name of the application the data directory is
// being requested for. This function will prepend a period to the appName for
// POSIX style operating systems since that is standard practice. An empty
// appName or one with a single dot is treated as requesting the current
// directory so only "." will be returned. Further, the first character
// of appName will be made lowercase for POSIX style operating systems and
// uppercase for Mac and Windows since that is standard practice.
//
// The roaming parameter only applies to Windows where it specifies the roaming
// application data profile (%APPDATA%) should be used instead of the local one
// (%LOCALAPPDATA%) that is used by default.
//
// Example results:
//
// dir := AppDataDir("myapp", false)
// POSIX (Linux/BSD): ~/.myapp
// Mac OS: $HOME/Library/Application Support/Myapp
// Windows: %LOCALAPPDATA%\Myapp
// Plan 9: $home/myapp
func AppDataDir(appName string, roaming bool) string {
return appDataDir(runtime.GOOS, appName, roaming)
}