Release v0.1.0

vendor/github.com/btcsuite/btcutil/appdata.go

@@ -0,0 +1,105 @@
+// 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:]
+
+	// Get the OS specific home directory via the Go standard lib.
+	var homeDir string
+	usr, err := user.Current()
+	if err == nil {
+		homeDir = usr.HomeDir
+	}
+
+	// Fall back to standard HOME environment variable that works
+	// for most POSIX OSes if the directory from the Go standard
+	// lib failed.
+	if err != nil || homeDir == "" {
+		homeDir = os.Getenv("HOME")
+	}
+
+	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)
+}