From: Caspar Schutijser <caspar@schutijser.com>
Subject: Re: Change pax(1) default write format
To: Jeremie Courreges-Anglas <jca@wxcvbn.org>
Cc: tech@openbsd.org, millert@openbsd.org
Date: Mon, 15 Apr 2024 19:34:16 +0200

On Mon, Apr 15, 2024 at 06:19:05PM +0200, Jeremie Courreges-Anglas wrote:
> From 'ustar' to 'pax'.
> 
> Since by default most files get an extended header for atime and
> mtime, the size of archives increases with lots of small files.  But
> it gets much better after compression:
> 
> pbuild /tmp$ ls -lh /tmp/ports.*
> -rw-r--r--  1 jca  wheel   988M Apr 15 17:46 /tmp/ports.pax
> -rw-r--r--  1 jca  wheel   806M Apr 15 17:46 /tmp/ports.tar
> pbuild /tmp$ gzip -9 ports.pax ports.tar
> pbuild /tmp$ ls -lh /tmp/ports.*
> -rw-r--r--  1 jca  wheel   355M Apr 15 17:46 /tmp/ports.pax.gz
> -rw-r--r--  1 jca  wheel   350M Apr 15 17:46 /tmp/ports.tar.gz
> 
> install sets for amd64 grow by 1.8MB which isn't much either.
> 
> I suspect we'll end up doing the same for tar(1), but for that tool
> I'd like to give people options to opt out first.
> 
> ok?
> 
> 
> Index: options.c
> ===================================================================
> RCS file: /cvs/src/bin/pax/options.c,v
> diff -u -p -r1.107 options.c
> --- options.c	9 Dec 2023 23:00:11 -0000	1.107
> +++ options.c	15 Apr 2024 11:51:24 -0000
> @@ -238,7 +238,11 @@ FSUB fsub[] = {
>  #define	F_CPIO	3	/* format when called as cpio */
>  #define F_OTAR	4	/* format when called as tar -o */
>  #define F_TAR	5	/* format when called as tar */
> -#define DEFLT	5	/* default write format from list above */
> +#ifdef SMALL
> +# define DEFLT	5	/* format when called as pax: ustar */
                                   ^^^
I would write "default write format when called as pax: ustar" like
what it was previously.

> +#else
> +# define DEFLT	10	/* format when called as pax: pax */

And similar here.


Either way, I like this idea.

Caspar

> +#endif
>  
>  /*
>   * ford is the archive search order used by get_arc() to determine what kind
> Index: pax.1
> ===================================================================
> RCS file: /cvs/src/bin/pax/pax.1,v
> diff -u -p -r1.77 pax.1
> --- pax.1	9 Dec 2023 23:00:11 -0000	1.77
> +++ pax.1	15 Apr 2024 11:56:52 -0000
> @@ -810,7 +810,7 @@ field as described in
>  for more information about device IDs.
>  .It Fl x Ar format
>  Specify the output archive format, with the default format being
> -.Cm ustar .
> +.Cm pax .
>  .Nm
>  currently supports the following formats:
>  .Bl -tag -width "sv4cpio"
> 
> -- 
> jca
>