From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS17314 8.43.84.0/22 X-Spam-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI,NICE_REPLY_A, PDS_RDNS_DYNAMIC_FP,RCVD_IN_DNSWL_MED,RDNS_DYNAMIC,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (ip-8-43-85-97.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id BE77D1F8C6 for ; Fri, 30 Jul 2021 11:47:32 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 492253943540 for ; Fri, 30 Jul 2021 11:47:31 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 492253943540 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1627645651; bh=zu+j36tJzgwTv9S/PS0mcvRxLGYCGBDHoi6JUPrgB98=; h=Subject:To:References:Date:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=dx36Tt3Ub1Oqg+792PhFPuUbOsrEJmOQADCbVeV8ppA5hOs4q5Q7ApoNtSf2pTph3 VD8VUIATH210NjNkA8kH8qeJH1mIPA7o/vNRy9UHHqtbmicsIRGB5HWC2+6FzephdH FNnmYx77w8P2u/NFJB0lOEer6uQujDx95lB5w6gc= Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by sourceware.org (Postfix) with ESMTPS id 316A4388940C for ; Fri, 30 Jul 2021 11:47:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 316A4388940C Received: by mail-wr1-x42f.google.com with SMTP id p5so10954645wro.7 for ; Fri, 30 Jul 2021 04:47:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=zu+j36tJzgwTv9S/PS0mcvRxLGYCGBDHoi6JUPrgB98=; b=htTsyWMxISnhzjGcqh+YtOhpND9xeSalGEpDgANbr0RMvFX/9mIM2SaFMxPGmXUKEO EwuXXaSVikhAchyl68/wC1StUiWycOWeWhedB8+EPINnhvI2bf3fah/bBEc71H1oyibF 0rr0GycBUkEkK582X84kDyijLdv/OGTJx6pn5o0sToznspmTv6jYuTwx+E0LUjhidjLW BB9IIv/+J1shf6DT2/Yv5hq1erkRA0xRl12lUYYJtjtO+kWnZ7vHDIu2l0+2VpbeO7yX P6HQUR14nW5wxdS6lV6C2MBRCRpvWLtMY4cOhjfW27GZw5wbR2d3AjGe50OScqM/FYhF OZGw== X-Gm-Message-State: AOAM532L+M04lBOohUZWvF3sQlQc/3JbeiYtCJUJNwh/DPhelEVxFh17 O3rUKnyWhl2E9tPgs6tjhOWvso/AHwM= X-Google-Smtp-Source: ABdhPJwt1c9OSil3hWr8y87rahBeeTK96SmuIKxFKbOqTYNRrvZ7m/V9o497wiBAqRWKf5LtGzdJxg== X-Received: by 2002:adf:ed50:: with SMTP id u16mr2612454wro.174.1627645628331; Fri, 30 Jul 2021 04:47:08 -0700 (PDT) Received: from [10.8.0.10] ([195.53.121.100]) by smtp.gmail.com with ESMTPSA id e5sm1776292wrr.36.2021.07.30.04.47.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 30 Jul 2021 04:47:07 -0700 (PDT) Subject: Re: [PATCH] ioctl_tty.2: Add example how to get or set baudrate on the serial port To: =?UTF-8?Q?Pali_Roh=c3=a1r?= References: <20210730095333.6118-1-pali@kernel.org> Message-ID: Date: Fri, 30 Jul 2021 13:47:06 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210730095333.6118-1-pali@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: "Alejandro Colomar \(man-pages\) via Libc-alpha" Reply-To: "Alejandro Colomar \(man-pages\)" Cc: =?UTF-8?Q?Marek_Beh=c3=ban?= , "G. Branden Robinson" , libc-alpha@sourceware.org, Michael Kerrisk , linux-man@vger.kernel.org Errors-To: libc-alpha-bounces+e=80x24.org@sourceware.org Sender: "Libc-alpha" Hi Pali, On 7/30/21 11:53 AM, Pali Rohár wrote: > Signed-off-by: Pali Rohár Thanks for the patch! Please see some comments below. Cheers, Alex > --- > man2/ioctl_tty.2 | 60 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 60 insertions(+) > > diff --git a/man2/ioctl_tty.2 b/man2/ioctl_tty.2 > index 0b0083c671a7..9d394572ae93 100644 > --- a/man2/ioctl_tty.2 > +++ b/man2/ioctl_tty.2 > @@ -750,6 +750,66 @@ main(void) > close(fd); > } > .EE > +.PP > +Get or set arbitrary baudrate on the serial port. > +.PP > +.EX > +#include > +#include > +#include > +#include > +#include > +#include > +#include Unless there's a reason to use a specific include order (and if so, add a comment), please use alphabetical order. > + > +int > +main(int argc, char *argv[]) > +{ > +#if !defined(TCGETS2) || !defined(TCSETS2) || !defined(BOTHER) > + fprintf(stderr, "TCGETS2, TCSETS2 or BOTHER is unsupported\\n"); > + return 1; > +#else Do we want the program to compile if those are unsupported? Maybe you can #error there and simplify the reader having to parse the preprocessor directive mentally: #if !defined... # error ... #endif I know it's non-standard, but I think it's common enough so that we can use it here. > + struct termios2 tio2; > + int fd, rc; > + > + if (argc != 2 && argc != 3) { > + fprintf(stderr, "Usage: %s device [new_baudrate]\\n", argv[0]); We use \e for printing the escape character. Not \\ CC: Branden See groff_man(7): Portability [...] Similar caveats apply to escapes. Some escape sequences are however required for correct typesetting even in man pages and usually do not cause portability problems: [...] \e Widely used in man pages to represent a backslash output glyph. It works reliably as long as the .ec request is not used, which should never happen in man pages, and it is slightly more portable than the more exact ‘\(rs’ (“reverse solidus”) escape se‐ quence. > + return 1; > + } > + > + fd = open(argv[1], O_RDWR | O_NONBLOCK | O_NOCTTY); > + if (fd < 0) { > + perror("open"); > + return 1; exit(EXIT_FAILURE); > + } > + > + rc = ioctl(fd, TCGETS2, &tio2); > + if (rc) { > + perror("TCGETS2"); > + close(fd); > + return 1; exit(3) > + } > + > + printf("%u\\n", tio2.c_ospeed); \e > + > + if (argc == 3) { > + tio2.c_cflag &= ~CBAUD; > + tio2.c_cflag |= BOTHER; > + tio2.c_ospeed = tio2.c_ispeed = atoi(argv[2]); > + > + rc = ioctl(fd, TCSETS2, &tio2); > + if (rc) { > + perror("TCSETS2"); > + close(fd); > + return 1; exit(3) > + } > + } > + > + close(fd); > + return 0; exit(3) > +#endif > +} > +.EE > .SH SEE ALSO > .BR ldattach (1), > .BR ioctl (2), > -- Alejandro Colomar Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es/