Expand ~ in configuration

Fixes #60

Author: zyedidia

config.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/BurntSushi/toml"
 	"github.com/jessevdk/go-flags"
+	"github.com/zyedidia/eget/home"
 )
 
 type ConfigGlobal struct {
@@ -150,7 +151,7 @@ func InitializeConfig() (*Config, error) {
 		}
 
 		if !config.Meta.MetaData.IsDefined(name, "target") {
-			repo.Target = config.Global.Target
+			repo.Target, err = home.Expand(config.Global.Target)
 		}
 
 		if !config.Meta.MetaData.IsDefined(name, "upgrade_only") {

home/home.go

@@ -0,0 +1,44 @@
+package home
+
+import (
+	"fmt"
+	"os/user"
+	"path/filepath"
+	"strings"
+)
+
+func Home() (string, error) {
+	userData, err := user.Current()
+	if err != nil {
+		return "", fmt.Errorf("find homedir: %w", err)
+	}
+	return userData.HomeDir, err
+}
+
+// Expand takes a path as input and replaces ~ at the start of the path with the user's
+// home directory. Does nothing if the path does not start with '~'.
+func Expand(path string) (string, error) {
+	if !strings.HasPrefix(path, "~") {
+		return path, nil
+	}
+
+	var userData *user.User
+	var err error
+
+	homeString := strings.Split(filepath.ToSlash(path), "/")[0]
+	if homeString == "~" {
+		userData, err = user.Current()
+		if err != nil {
+			return "", fmt.Errorf("expand tilde: %w", err)
+		}
+	} else {
+		userData, err = user.Lookup(homeString[1:])
+		if err != nil {
+			return "", fmt.Errorf("expand tilde: %w", err)
+		}
+	}
+
+	home := userData.HomeDir
+
+	return strings.Replace(path, homeString, home, 1), nil
+}