From: Omar Polo <op@omarpolo.com>
Subject: Re: mg: move up directory in dired
To: Dante Catalfamo <dante@lambda.cx>
Cc: tech@openbsd.org
Date: Mon, 03 Jun 2024 19:05:50 +0200

On 2024/06/02 02:12:57 -0400, Dante Catalfamo <dante@lambda.cx> wrote:
> I had forgotten to add the command to the function map

Looks great to me!  I've missed something like this to jump to the
parent directory quickly than searching for the '..' entry.

I have a few nits, mostly on the style, but if noone complains I'll
commit in a few days.

> [...]
> +int
> +d_updirectory(int f, int n)
> +{
> +
> +	struct buffer *bp;
> +	int ret;
> +	char  fname[NFILEN];

nit: I'd keep these aligned as in the rest of the file.

> +	ret = snprintf(fname, sizeof(fname), "%s..", curbp->b_fname);
> +	if (ret < 0 || ret >= (int)sizeof(fname))

nit/cargo culting: to stay closer to the "proper secure idiom" outlined
in printf(3) CAVEATS section, I'd change the casting to

	if (ret < 0 || (size_t)ret >= sizeof(buff))

even if in practice it's exactly the same stuff.

> +		return (ABORT); /* Name is too long. */
> +
> +	bp = dired_(fname);
> +	if (bp == NULL)
> +		return (FALSE);
> +	curbp = bp;
> +	if (showbuffer(bp, curwp, WFFULL) != TRUE)
> +		return (FALSE);
> +	if (bp->b_fname[0] != 0)
> +		return (TRUE);
> +	return (readin(fname));
> +}

Then I also think we should document this addition in mg.1.  I'm
attaching an updated diff with the manpage addition, plus a proposed
follow-up

diff -s /usr/src
commit - 47c8d1014851805fa59b884ed3dceb148358575f
path + /usr/src (staged changes)
blob - 579ac9a124f4e66007c8dcdd88d2c8f10aad71d9
blob + 2fcb1c49f374b02c58136c3267d7171acfd2655e
--- usr.bin/mg/dired.c
+++ usr.bin/mg/dired.c
@@ -34,6 +34,7 @@ static int	 d_otherwindow(int, int);
 static int	 d_undel(int, int);
 static int	 d_undelbak(int, int);
 static int	 d_findfile(int, int);
+static int	 d_updirectory(int, int);
 static int	 d_ffotherwindow(int, int);
 static int	 d_expunge(int, int);
 static int	 d_copy(int, int);
@@ -122,6 +123,10 @@ static PF diredcz[] = {
 	d_create_directory	/* + */
 };
 
+static PF diredcaret[] = {
+	d_updirectory /* ^ */
+};
+
 static PF direda[] = {
 	d_filevisitalt,		/* a */
 	rescan,			/* b */
@@ -172,9 +177,9 @@ static struct KEYMAPE (1) d_backpagemap = {
 	}
 };
 
-static struct KEYMAPE (7) diredmap = {
-	7,
-	7,
+static struct KEYMAPE (8) diredmap = {
+	8,
+	8,
 	rescan,
 	{
 		{
@@ -191,6 +196,9 @@ static struct KEYMAPE (7) diredmap = {
 			CCHR('Z'), '+', diredcz, (KEYMAP *) & metamap
 		},
 		{
+			'^', '^', diredcaret, NULL
+		},
+		{
 			'a', 'j', direda, NULL
 		},
 		{
@@ -224,6 +232,7 @@ dired_init(void)
 	funmap_add(d_undel, "dired-unmark", 0);
 	funmap_add(d_undelbak, "dired-unmark-backward", 0);
 	funmap_add(d_killbuffer_cmd, "quit-window", 0);
+	funmap_add(d_updirectory, "dired-up-directory", 0);
 	maps_add((KEYMAP *)&diredmap, "dired");
 	dobindkey(fundamental_map, "dired", "^Xd");
 }
@@ -364,6 +373,28 @@ d_findfile(int f, int n)
 }
 
 int
+d_updirectory(int f, int n)
+{
+	struct buffer	*bp;
+	int		 ret;
+	char		 fname[NFILEN];
+
+	ret = snprintf(fname, sizeof(fname), "%s..", curbp->b_fname);
+	if (ret < 0 || (size_t)ret >= sizeof(fname))
+		return (ABORT); /* Name is too long. */
+
+	bp = dired_(fname);
+	if (bp == NULL)
+		return (FALSE);
+	curbp = bp;
+	if (showbuffer(bp, curwp, WFFULL) != TRUE)
+		return (FALSE);
+	if (bp->b_fname[0] != 0)
+		return (TRUE);
+	return (readin(fname));
+}
+
+int
 d_ffotherwindow(int f, int n)
 {
 	char		 fname[NFILEN];
blob - 4faeb8fb293954d061e883a8a53482743afcde3b
blob + 366d6087064a44bb3d28a750e3a7d4a8258adc5f
--- usr.bin/mg/mg.1
+++ usr.bin/mg/mg.1
@@ -1055,6 +1055,8 @@ dired-next-line
 dired-shell-command
 .It +
 dired-create-directory
+.It ^
+dired-up-directory
 .It a
 dired-find-alternate-file
 .It c
@@ -1130,6 +1132,8 @@ Remove the deletion flag for the file on the current l
 .It Ic dired-unmark-backward
 Remove the deletion flag from the file listed on the previous line
 of the dired buffer, then move up to that line.
+.It Ic dired-up-directory
+Open a dired buffer in the parent directory.
 .It Ic quit-window
 Close the current dired buffer.
 .El


Then, since we have dired-up-directory, I'd propose to use it in
dired-jump since it's handy to keep pressing C-x C-j to navigate
upwards.  GNU Emacs does this by default too.

diff /usr/src
commit - 47c8d1014851805fa59b884ed3dceb148358575f
path + /usr/src
blob - 2fcb1c49f374b02c58136c3267d7171acfd2655e (staged)
file + usr.bin/mg/dired.c
--- usr.bin/mg/dired.c
+++ usr.bin/mg/dired.c
@@ -1125,7 +1125,7 @@ dired_jump(int f, int n)
 	for (i = 0; i <= curbp->b_nmodes; i++) {
 		modename = curbp->b_modes[i]->p_name;
 		if (strncmp(modename, "dired", 5) == 0)
-			return (dobeep_msg("In dired mode already"));
+			return (d_updirectory(f, n));
 	}
 
 	if (getbufcwd(dname, sizeof(dname)) != TRUE)


Thanks!