use shell to resolve special paths with ~

examples/dev.yaml

@@ -8,6 +8,7 @@ global:
     default-command: snapshots
     initialize: false
     priority: low
+    restic-binary: ~/fake_restic
 
 groups:
     full-backup:

filesearch/filesearch.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"github.com/adrg/xdg"
+	"github.com/creativeprojects/clog"
 )
 
 var (
@@ -126,9 +127,15 @@ func findConfigurationFileWithExtension(configFile string) string {
 
 // FindResticBinary returns the path of restic executable
 func FindResticBinary(configLocation string) (string, error) {
-	// Start by the location from the configuration
-	if configLocation != "" && fileExists(configLocation) {
-		return configLocation, nil
+	if configLocation != "" {
+		// Start by the location from the configuration
+		configLocation, err := ShellExpand(configLocation)
+		if err != nil {
+			clog.Warning(err)
+		}
+		if configLocation != "" && fileExists(configLocation) {
+			return configLocation, nil
+		}
 	}
 	paths := getDefaultBinaryLocations()
 	binaryFile := getResticBinary()
@@ -149,6 +156,21 @@ func FindResticBinary(configLocation string) (string, error) {
 	return filename, nil
 }
 
+// ShellExpand uses the shell to expand variables and ~ from a filename.
+// On Windows the function simply returns the filename unchanged
+func ShellExpand(filename string) (string, error) {
+	if runtime.GOOS == "windows" {
+		return filename, nil
+	}
+	cmd := exec.Command("sh", "-c", fmt.Sprintf("echo %s", strings.ReplaceAll(filename, " ", `\ `)))
+	result, err := cmd.Output()
+	if err != nil {
+		return filename, err
+	}
+	filename = strings.TrimSuffix(string(result), "\n")
+	return filename, nil
+}
+
 func getDefaultConfigurationLocations() []string {
 	if runtime.GOOS == "windows" {
 		return defaultConfigurationLocationsWindows

filesearch/filesearch_test.go

@@ -2,7 +2,9 @@ package filesearch
 
 import (
 	"os"
+	"os/user"
 	"path/filepath"
+	"runtime"
 	"strings"
 	"testing"
 
@@ -223,3 +225,55 @@ func TestFindResticBinary(t *testing.T) {
 		assert.Error(t, err)
 	}
 }
+
+func TestFindResticBinaryWithTilde(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("not supported on Windows")
+		return
+	}
+	home, err := os.UserHomeDir()
+	require.NoError(t, err)
+
+	tempFile, err := os.CreateTemp(home, "TestFindResticBinaryWithTilde")
+	require.NoError(t, err)
+	tempFile.Close()
+	defer func() {
+		os.Remove(tempFile.Name())
+	}()
+
+	search := filepath.Join("~", filepath.Base(tempFile.Name()))
+	binary, err := FindResticBinary(search)
+	require.NoError(t, err)
+	assert.Equalf(t, tempFile.Name(), binary, "cannot find %q", search)
+}
+
+func TestShellExpand(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("not supported on Windows")
+		return
+	}
+	home, err := os.UserHomeDir()
+	require.NoError(t, err)
+
+	user, err := user.Current()
+	require.NoError(t, err)
+
+	testData := []struct {
+		source   string
+		expected string
+	}{
+		{"/", "/"},
+		{"~", home},
+		{"$HOME", home},
+		{"~" + user.Username, user.HomeDir},
+		{"1 2", "1 2"},
+	}
+
+	for _, testItem := range testData {
+		t.Run(testItem.source, func(t *testing.T) {
+			result, err := ShellExpand(testItem.source)
+			require.NoError(t, err)
+			assert.Equal(t, testItem.expected, result)
+		})
+	}
+}