Support directories in path to :save

This adds new functionality to :save in the message view for specifying
directories in the path. A new flag, -p, is also added to :save for
automatically creating any directories in the path that do not exist.

If the path ends in a / (e.g. "Downloads/mail/") or if the path is an
existing directory, the part's file name is the filename from the mail
header for the part. Otherwise, it uses the last element in the path as
the filename (e.g. 'blah.jpg' is the filename if the path is
'Downloads/mail/blah.jpg')

commands/msgview/save.go

@@ -6,9 +6,11 @@ import (
 	"io"
 	"mime/quotedprintable"
 	"os"
+	"path/filepath"
 	"time"
 
 	"git.sr.ht/~sircmpwn/aerc/widgets"
+	"git.sr.ht/~sircmpwn/getopt"
 	"github.com/mitchellh/go-homedir"
 )
 
@@ -17,9 +19,24 @@ func init() {
 }
 
 func Save(aerc *widgets.Aerc, args []string) error {
-	if len(args) < 2 {
-		return errors.New("Usage: :save <path>")
+	opts, optind, err := getopt.Getopts(args, "p")
+	if err != nil {
+		return err
 	}
+	var (
+		mkdirs bool
+		path   string
+	)
+	for _, opt := range opts {
+		switch opt.Option {
+		case 'p':
+			mkdirs = true
+		}
+	}
+	if len(args) <= optind {
+		return errors.New("Usage: :save [-p] <path>")
+	}
+	path = args[optind]
 
 	mv := aerc.SelectedTab().(*widgets.MessageViewer)
 	p := mv.CurrentPart()
@@ -33,12 +50,44 @@ func Save(aerc *widgets.Aerc, args []string) error {
 			reader = quotedprintable.NewReader(reader)
 		}
 
-		target, err := homedir.Expand(args[1])
+		var pathIsDir bool
+		if path[len(path)-1:] == "/" {
+			pathIsDir = true
+		}
+		// Note: path expansion has to happen after test for trailing /,
+		// since it is stripped when path is expanded
+		path, err := homedir.Expand(path)
 		if err != nil {
 			aerc.PushError(" " + err.Error())
-			return
 		}
 
+		pathinfo, err := os.Stat(path)
+		if err == nil && pathinfo.IsDir() {
+			pathIsDir = true
+		} else if os.IsExist(err) && pathIsDir {
+			aerc.PushError("The given directory is an existing file")
+		}
+
+		// Use attachment name as filename if given path is a directory
+		save_file := filepath.Base(path)
+		save_dir := filepath.Dir(path)
+		if pathIsDir {
+			save_dir = path
+			if filename, ok := p.Part.DispositionParams["filename"]; ok {
+				save_file = filename
+			}
+		}
+		if _, err := os.Stat(save_dir); os.IsNotExist(err) {
+			if mkdirs {
+				os.MkdirAll(save_dir, 0755)
+			} else {
+				aerc.PushError("Target directory does not exist, use " +
+					":save with the -p option to create it")
+				return
+			}
+		}
+		target := filepath.Clean(filepath.Join(save_dir, save_file))
+
 		f, err := os.Create(target)
 		if err != nil {
 			aerc.PushError(" " + err.Error())

doc/aerc.1.scd

@@ -119,9 +119,11 @@ message list, the message in the message viewer, etc).
 	Downloads and pipes the current message part into the given shell command,
 	and opens a new terminal tab to show the result.
 
-*save* <path>
+*save* [-p] <path>
 	Saves the current message part to the given path.
 
+	*-p*: Make any directories in the path that do not exist
+
 *close*
 	Closes the message viewer.