From: enh <enh@google.com>
Subject: Re: Implement tcgetwinsize and tcsetwinsize
To: finxx <me@finxx.xyz>
Cc: tech@openbsd.org
Date: Sun, 23 Feb 2025 15:22:32 -0800

On Sun, Feb 23, 2025 at 2:14 PM finxx <me@finxx.xyz> wrote:
>
> tcgetwinsize(3) and tcsetwinsize(3) have existed in POSIX for years,

well, since 2024's issue 8 anyway.

> and
> been supported on the other BSDs for just as long. This patch implements
> them in libc.
>
> diff 11d817a3382201927643a2ae0a36dcc4048bfb0b HEAD
> commit - 11d817a3382201927643a2ae0a36dcc4048bfb0b
> commit + c077581a317e8f39c250c631d6d29b01a97e7f8a
> blob - 6eb2cca93e5f1c834a57a03af4a4b3fe27c64ce1
> blob + 18cf144e7a06b88f2514407c57cda12d192d7709
> --- lib/libc/Symbols.list
> +++ lib/libc/Symbols.list
> @@ -1700,9 +1700,11 @@ tcflush
>  tcgetattr
>  tcgetpgrp
>  tcgetsid
> +tcgetwinsize
>  tcsendbreak
>  tcsetattr
>  tcsetpgrp
> +tcsetwinsize
>
>  /* thread */
>  _rthread_debug
> blob - 85c1d52273c9cb24478c2c7e67a79bbdd86dae51
> blob + a1aff88ae34741f62149e88c69c93f6b5b7326c6
> --- lib/libc/termios/Makefile.inc
> +++ lib/libc/termios/Makefile.inc
> @@ -4,6 +4,7 @@
>
>  SRCS+= cfgetispeed.c cfgetospeed.c cfmakeraw.c cfsetispeed.c cfsetospeed.c \
>         cfsetspeed.c tcdrain.c tcflow.c tcflush.c tcgetattr.c tcgetpgrp.c \
> -       tcsendbreak.c tcsetattr.c tcsetpgrp.c tcgetsid.c
> +       tcsendbreak.c tcsetattr.c tcsetpgrp.c tcgetsid.c tcgetwinsize.c \
> +       tcsetwinsize.c
>
>  MAN+=  tcgetpgrp.3 tcsendbreak.3 tcsetattr.3 tcsetpgrp.3 tcgetsid.3
> blob - /dev/null
> blob + c41b49129a7c60230f20f727ce90f7e4b089cd30 (mode 644)
> --- /dev/null
> +++ lib/libc/termios/tcgetwinsize.c
> @@ -0,0 +1,24 @@
> +/*
> + * Copyright (c) 2025 Finxx <me@finxx.xyz>
> + *
> + * Permission to use, copy, modify, and distribute this software for any
> + * purpose with or without fee is hereby granted, provided that the above
> + * copyright notice and this permission notice appear in all copies.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
> + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
> + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
> + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
> + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
> + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
> + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> + */
> +
> +#include <sys/ioctl.h>
> +#include <termios.h>
> +
> +int
> +tcgetwinsize(int fd, struct winsize *winsize_p)
> +{
> +       return (ioctl(fd, TIOCGWINSZ, winsize_p));
> +}
> blob - /dev/null
> blob + 7e652d5f8457bb752b724c14cbfbdd9dc15f0564 (mode 644)
> --- /dev/null
> +++ lib/libc/termios/tcsetwinsize.c
> @@ -0,0 +1,24 @@
> +/*
> + * Copyright (c) 2025 Finxx <me@finxx.xyz>
> + *
> + * Permission to use, copy, modify, and distribute this software for any
> + * purpose with or without fee is hereby granted, provided that the above
> + * copyright notice and this permission notice appear in all copies.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
> + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
> + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
> + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
> + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
> + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
> + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> + */
> +
> +#include <sys/ioctl.h>
> +#include <termios.h>
> +
> +int
> +tcsetwinsize(int fd, const struct winsize *winsize_p)
> +{
> +       return (ioctl(fd, TIOCSWINSZ, winsize_p));
> +}
> blob - 681c29489138850507516a8ef6bc346bed04e4e9
> blob + 62a2d7a676481ae3fd947c15e237d4a5b018c1ca
> --- sys/sys/termios.h
> +++ sys/sys/termios.h
> @@ -272,6 +272,8 @@ int tcdrain(int);
>  int    tcflow(int, int);
>  int    tcflush(int, int);
>  int    tcsendbreak(int, int);
> +int    tcgetwinsize(int, struct winsize *);
> +int    tcsetwinsize(int, const struct winsize *);
>
>  #if __XPG_VISIBLE >= 420 || __POSIX_VISIBLE >= 200809

this makes me wonder whether tcgetwinsize()/tcsetwinsize() should be
guarded by __POSIX_VISIBLE too?

>  pid_t  tcgetsid(int);
>