Re: [9front] PATCH walk(1) to (optionally) quote name and path

[ori@eigenstate.org]

Quoth Romano <unobe@cpan.org>:
> I'm working with files on a backup drive that have spaces and
> quotation marks in their names, using walk(1).  I can pipe to sed
> s/''''/''''''''''/g and do similarly for other characters requiring
> escaping for rc(1), but figured patching walk(1) would be better.

generally no objections, though it's usually relatively easy to
structure scripts such that there's relatively little that is
interpreted by rc; is this for interactive use?

> I don't like how I just copied case 'p': the quoting "works", but isn't
> as clean as the output for ls(1).

I'll need to look at the code to see if there's a way to
improve this; regardless, a few comments inline:

> But it's better than what happens now, where there's no quoting.
> 
> From: Romano <unobe@cpan.org>
> Date: Sat, 12 Aug 2023 03:18:22 +0000
> Subject: [PATCH] walk: quote name and paths using N and P
> 
> ---
> diff deb39a43ae5ed09c7971726cedeb06a9f65ccc6d 2da52094832662c533f60629813dbd5ac805e3ad
> --- a/sys/man/1/walk
> +++ b/sys/man/1/walk
> @@ -81,8 +81,14 @@
>  .B n
>  final path element (name)
>  .TP
> +.B N
> +final path element (name), rc (1) quoted when necessary
> +.TP
>  .B p
>  path
> +.TP
> +.B P
> +path, rc (1) quoted when necessary
>  .TP
>  .B q
>  qid path.version.type (see
> --- a/sys/src/cmd/walk.c
> +++ b/sys/src/cmd/walk.c
> @@ -43,7 +43,7 @@
>  void
>  dofile(char *path, Dir *f, int pathonly)
>  {
> -	char *p;
> +	char *p, *quoted;

nitpicking on style; perhaps '*q' instead of '*quoted'

>  
>  	if(
>  		(f == dotdir)
> @@ -60,6 +60,10 @@
>  		case 'a': Bprint(bout, "%uld", f->atime); break;
>  		case 'm': Bprint(bout, "%uld", f->mtime); break;
>  		case 'n': Bwrite(bout, f->name, strlen(f->name)); break;
> +		case 'N':
> +			quoted = quotestrdup(f->name);
> +			Bwrite(bout, quoted, strlen(quoted));

looks like this leaks 'quoted'; same with all other quotestrdup calls.

> +			break;
>  		case 'p':
>  			if(path != dotpath)
>  				Bwrite(bout, path, strlen(path));
> @@ -69,6 +73,18 @@
>  				Bwrite(bout, f->name, strlen(f->name));
>  			}
>  			break;
> +		case 'P':

this quoting could be done by concating the path and the
dotpath, possibly even with libstring. Not sure if it'd
be cleaner to dedup the 'p' and 'P' cases or not yet.

> +			if(path != dotpath) {
> +				quoted = quotestrdup(path);
> +				Bwrite(bout, quoted, strlen(quoted));
> +			}
> +			if(! (f->qid.type & QTDIR) && !pathonly){
> +				if(path != dotpath)
> +					Bputc(bout, '/');
> +				quoted = quotestrdup(f->name);
> +				Bwrite(bout, quoted, strlen(quoted));
> +			}
> +			break;
>  		case 'q': Bprint(bout, "%ullx.%uld.%.2uhhx", f->qid.path, f->qid.vers, f->qid.type); break;
>  		case 's': Bprint(bout, "%lld", f->length); break;
>  		case 'x': Bprint(bout, "%M", f->mode); break;
> @@ -243,7 +259,7 @@
>  		if((stfmt = s_reset(stfmt)) == nil)
>  			sysfatal("s_reset: %r");
>  		s_append(stfmt, EARGF(usage()));
> -		i = strspn(s_to_c(stfmt), "UGMamnpqsxDT");
> +		i = strspn(s_to_c(stfmt), "UGMamnNpPqsxDT");
>  		if(i != s_len(stfmt))
>  			sysfatal("bad stfmt: %s", s_to_c(stfmt));
>  		break;
>