All of lore.kernel.org
 help / color / mirror / Atom feed
From: david.laight.linux@gmail.com
To: "Willy Tarreau" <w@1wt.eu>,
	"Thomas Weißschuh" <linux@weissschuh.net>,
	linux-kernel@vger.kernel.org, "Cheng Li" <lechain@gmail.com>
Cc: David Laight <david.laight.linux@gmail.com>
Subject: [PATCH next 00/12] tools/nolibc: Enhance printf()
Date: Tue,  3 Feb 2026 10:29:48 +0000	[thread overview]
Message-ID: <20260203103000.20206-1-david.laight.linux@gmail.com> (raw)

From: David Laight <david.laight.linux@gmail.com>

Update printf() so that it handles almost all the non-fp formats.
In particular:
- Left alignment.
- Zero padding.
- Field precision.
- Variable field width and precision.
- Width modifiers q, L, t and z.
- Conversion specifiers i and X (X generates lower case).
About the only thing that is missing is octal.

The tests are updated to match.

There is a slight increase in code size, but it is minimalised
by the the heavy use of bit-pattern matches.

vfprintf() is modified to buffer data for each call and do a single
write system call at the end.
This improves performance somewhat, but is actually most useful when
using strace.

David Laight (12):
  tools/nolibc/printf: Move snprintf length check to callback
  tools/nolibc/printf: Add buffering to vfprintf() callback.
  tools/nolibc: change printf() to output pad in 16 byte chunks
  selftests/nolibc: Improve reporting of vfprintf() errors
  tools/nolibc/stdio: Simplify __nolibc_printf()
  tools/nolibc: Add support for left alignment and %[tzq]d" to printf
  tools/nolibc: printf() prepend the sign after a numeric conversion
  tools/nolibc: use bit-match to detect valid printf conversion
    character
  tools/nolibc: add precision and zero padding to printf()
  tools/nolibc: Use bit-pattern for printf integral formats
  selftests/nolibc: Increase coverage of printf format tests
  selftests/nolibc: Use printf("%.*s", n, "") to align output

 tools/include/nolibc/stdio.h                 | 396 +++++++++++++------
 tools/testing/selftests/nolibc/nolibc-test.c |  96 +++--
 2 files changed, 336 insertions(+), 156 deletions(-)

-- 
2.39.5


             reply	other threads:[~2026-02-03 10:30 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-03 10:29 david.laight.linux [this message]
2026-02-03 10:29 ` [PATCH next 01/12] tools/nolibc/printf: Move length check to snprintf callback david.laight.linux
2026-02-03 10:29 ` [PATCH next 02/12] tools/nolibc/printf: Add buffering to vfprintf() callback david.laight.linux
2026-02-03 10:29 ` [PATCH next 03/12] tools/nolibc/printf: output pad spaces in 16 byte chunks david.laight.linux
2026-02-03 10:29 ` [PATCH next 04/12] selftests/nolibc: Improve reporting of vfprintf() errors david.laight.linux
2026-02-03 10:29 ` [PATCH next 05/12] tools/nolibc/printf: Simplify __nolibc_printf() david.laight.linux
2026-02-03 10:29 ` [PATCH next 06/12] tools/nolibc/printf: Add support for left alignment and %[tzLq]d" david.laight.linux
2026-02-04  4:14   ` Willy Tarreau
2026-02-04 10:17     ` David Laight
2026-02-04 10:40       ` Willy Tarreau
2026-02-04 15:39         ` David Laight
2026-02-03 10:29 ` [PATCH next 07/12] tools/nolibc/printf: Prepend the sign after a numeric conversion david.laight.linux
2026-02-03 10:29 ` [PATCH next 08/12] tools/nolibc/printf: use bit-match to detect valid conversion characters david.laight.linux
2026-02-03 10:29 ` [PATCH next 09/12] tools/nolibc/printf: support precision and zero padding david.laight.linux
2026-02-03 10:29 ` [PATCH next 10/12] tools/nolibc/printf: Use bit-pattern for integral formats david.laight.linux
2026-02-03 10:29 ` [PATCH 11/12] selftests/nolibc: Increase coverage of printf format tests david.laight.linux
2026-02-03 18:22   ` kernel test robot
2026-02-03 22:05     ` David Laight
2026-02-03 23:23   ` kernel test robot
2026-02-03 10:30 ` [PATCH 12/12] selftests/nolibc: Use printf("%.*s", n, "") to align output david.laight.linux
2026-02-03 17:39 ` [PATCH next 00/12] tools/nolibc: Enhance printf() David Laight

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260203103000.20206-1-david.laight.linux@gmail.com \
    --to=david.laight.linux@gmail.com \
    --cc=lechain@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@weissschuh.net \
    --cc=w@1wt.eu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.