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: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 24C231F463 for ; Wed, 25 Dec 2019 11:57:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726861AbfLYL5Q (ORCPT ); Wed, 25 Dec 2019 06:57:16 -0500 Received: from mail-ed1-f66.google.com ([209.85.208.66]:43549 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726435AbfLYL5H (ORCPT ); Wed, 25 Dec 2019 06:57:07 -0500 Received: by mail-ed1-f66.google.com with SMTP id dc19so19749015edb.10 for ; Wed, 25 Dec 2019 03:57:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=piNb8ps1Uqk/dtptwShlXphncXbdxXOUBitj8rIWJ6o=; b=AxF5/5UfyUEK9yrjDO+MzGWgTD9iycEO9I937iKwuskklq7uVMiy1Rz28pvL47x/C1 7jrVC19LMQNjBo3Hff5svuz8E+It6jPSdDcVuUr3RTOwo9mIJatBdUZ6cT+lZ4RTTnOf NT2StE5gG6gQRkblYB0dZBEJZ2gnY76mEP8O+fURlhaqjQ/fhSRKGwbb53GabYAwQTrs e885GPl+iyIfwNGTXs5dKs0jPccn03/I3cGvNvYBWUbdMB52Gcn79eBK6GA2aO3numOI Jr+W7uTGL8ZGHS1AlXXOMuOJntwX9MbRHC7JE2JNAYqlXyJeU9KiD8s1LZG3WmIfBQal NY8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=piNb8ps1Uqk/dtptwShlXphncXbdxXOUBitj8rIWJ6o=; b=rCy+lYKqw84v5DeYjVMprWAq+4/Vj9YuJ6heMRJzrpVwz/ICfbIRgm1DKkOSrMEHur DisMVEv1y7hQMuFR5WPkQPoPpiJsnv7sNxikmaLWb7aFMKGei/npgGcgPnOi16CIEHSS kdhcWqeWpIZ5kBDGphydxXih5pMElNFNVxY50MpN7ORerP2jTbCCIBGBSwKvWorJHk/v h0g6bgyxeN5zmmX5HIOQEOJdyy2CCs+GY+8REOkIv/BEJm5nVuUcsRA01Gk44X7tas9W fFFh+ejeBMIqV7GiXo9sf8iBU6KJb8fHKMR2ecnymB/5WFoIIArPUFqkt4nBLU2XdPji ZcGg== X-Gm-Message-State: APjAAAXT6hN1Bc+iQA4tEtT/x+OSC0J0Vmuu1xYg1ocE9L1HOQVwPJCr wosIsGqaZr/Z9a3aSCfG01JERhs4 X-Google-Smtp-Source: APXvYqxLOwA2s26p5VVVi1xxWzFRIw172LPlIIXkmY8oAYW1bf5JG7xDtMVDPxMpXGs5YocQ9NJ/1g== X-Received: by 2002:a17:906:8299:: with SMTP id h25mr12902910ejx.128.1577275025840; Wed, 25 Dec 2019 03:57:05 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id h61sm3053319edd.49.2019.12.25.03.57.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Dec 2019 03:57:05 -0800 (PST) Message-Id: <190fb4f5e911aca494647c36c9b09ac0cd232170.1577275020.git.gitgitgadget@gmail.com> In-Reply-To: References: From: "Johannes Schindelin via GitGitGadget" Date: Wed, 25 Dec 2019 11:56:56 +0000 Subject: [PATCH v2 5/9] terminal: add a new function to read a single keystroke Fcc: Sent Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 To: git@vger.kernel.org Cc: Johannes Schindelin , Junio C Hamano , Johannes Schindelin Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Johannes Schindelin Typically, input on the command-line is line-based. It is actually not really easy to get single characters (or better put: keystrokes). We provide two implementations here: - One that handles `/dev/tty` based systems as well as native Windows. The former uses the `tcsetattr()` function to put the terminal into "raw mode", which allows us to read individual keystrokes, one by one. The latter uses `stty.exe` to do the same, falling back to direct Win32 Console access. Thanks to the refactoring leading up to this commit, this is a single function, with the platform-specific details hidden away in conditionally-compiled code blocks. - A fall-back which simply punts and reads back an entire line. Note that the function writes the keystroke into an `strbuf` rather than a `char`, in preparation for reading Escape sequences (e.g. when the user hit an arrow key). This is also required for UTF-8 sequences in case the keystroke corresponds to a non-ASCII letter. Signed-off-by: Johannes Schindelin --- compat/terminal.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++ compat/terminal.h | 3 +++ 2 files changed, 58 insertions(+) diff --git a/compat/terminal.c b/compat/terminal.c index 16e9949da1..1b2564042a 100644 --- a/compat/terminal.c +++ b/compat/terminal.c @@ -60,6 +60,11 @@ static int disable_echo(void) return disable_bits(ECHO); } +static int enable_non_canonical(void) +{ + return disable_bits(ICANON | ECHO); +} + #elif defined(GIT_WINDOWS_NATIVE) #define INPUT_PATH "CONIN$" @@ -151,6 +156,10 @@ static int disable_echo(void) return disable_bits(ENABLE_ECHO_INPUT); } +static int enable_non_canonical(void) +{ + return disable_bits(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT); +} #endif @@ -198,6 +207,33 @@ char *git_terminal_prompt(const char *prompt, int echo) return buf.buf; } +int read_key_without_echo(struct strbuf *buf) +{ + static int warning_displayed; + int ch; + + if (warning_displayed || enable_non_canonical() < 0) { + if (!warning_displayed) { + warning("reading single keystrokes not supported on " + "this platform; reading line instead"); + warning_displayed = 1; + } + + return strbuf_getline(buf, stdin); + } + + strbuf_reset(buf); + ch = getchar(); + if (ch == EOF) { + restore_term(); + return EOF; + } + + strbuf_addch(buf, ch); + restore_term(); + return 0; +} + #else char *git_terminal_prompt(const char *prompt, int echo) @@ -205,4 +241,23 @@ char *git_terminal_prompt(const char *prompt, int echo) return getpass(prompt); } +int read_key_without_echo(struct strbuf *buf) +{ + static int warning_displayed; + const char *res; + + if (!warning_displayed) { + warning("reading single keystrokes not supported on this " + "platform; reading line instead"); + warning_displayed = 1; + } + + res = getpass(""); + strbuf_reset(buf); + if (!res) + return EOF; + strbuf_addstr(buf, res); + return 0; +} + #endif diff --git a/compat/terminal.h b/compat/terminal.h index 97db7cd69d..a9d52b8464 100644 --- a/compat/terminal.h +++ b/compat/terminal.h @@ -3,4 +3,7 @@ char *git_terminal_prompt(const char *prompt, int echo); +/* Read a single keystroke, without echoing it to the terminal */ +int read_key_without_echo(struct strbuf *buf); + #endif /* COMPAT_TERMINAL_H */ -- gitgitgadget