From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F99DC33C9E for ; Tue, 14 Jan 2020 18:44:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE26224670 for ; Tue, 14 Jan 2020 18:44:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aC5LYuk/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728803AbgANSoD (ORCPT ); Tue, 14 Jan 2020 13:44:03 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:51720 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728787AbgANSoB (ORCPT ); Tue, 14 Jan 2020 13:44:01 -0500 Received: by mail-wm1-f68.google.com with SMTP id d73so15044134wmd.1 for ; Tue, 14 Jan 2020 10:44:00 -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=aC5LYuk/0hYGsicrYyBsHuPx3FhdZEM9zqUx5LXeYch3R/lG4G3N0RyZC+8xY5TKeq z3mhkQ+VAJH99gKIPj6yKH0WWtN5O0DKRebpW2hH29mBrG7PpxikujYDm87MGYrp3Mah /FVIM/ubPRZl+CPmMTe7EuIJBgIaJUo+2B54erkIwktU8KnPyV07XmQuxDnViPf+fgBD vtHNxezYIcDaCHzA34JL5901DY1hChuz1gzPgZOy8mLWjK8X9Yxob/9t3tbj7ZCd+tzL Td0mM5OQc5QsCKK34W7qAjbhI2oNix7RflodSDBbNiagyWo6YRZ2Ddo7AtnwO1/ziatW UipQ== 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=niTEXLPVRk1zKIcOnE/vSlCa2GS5iTh5UtTdb9tzNXv4ynnFmZElI53rkm3UxTB6s+ apQ2QjOi7ax1/lKzZR5jzyXMIDATo9a6bbZC1I9Xe6Cz95LKlLz/5kyMHCpQRggRDSTt chOn8sowjBUb7K9KaLWYRwd7qQZ6HIj236l3zjl7fGyCjJepilXdyCUdgbBH1b4yG63e rahCfs0XflOFmnmAJqur2kXIEkhldZyeubpqgK+r2qv6gN1w8nmsGPaHB17AhuBqDTJ+ PCYNeYRo7K8IyA/oOxeejiX0XsgJju8SjDBKG/4x2h4AlpLmCbpNx3QQhocVLN/osPYe dMYA== X-Gm-Message-State: APjAAAXy9WKaTpsivaLCjZAzrk6rQH18zlOCrb0hW8OET9emUKqtsJRs rLXoI1ggpcDZiiS/2hSYlSSxxsQ7 X-Google-Smtp-Source: APXvYqwz1gtx4elFsv5KGLaobfFzQl8ybln6zArtmn6gc/U+bTgppJOZLF/eVMzKPRKNKEB9Le+hiA== X-Received: by 2002:a05:600c:2409:: with SMTP id 9mr27037830wmp.109.1579027439997; Tue, 14 Jan 2020 10:43:59 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id l7sm20978096wrq.61.2020.01.14.10.43.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jan 2020 10:43:59 -0800 (PST) Message-Id: <8d9c703f3b02cd784025dec5c0be682ea25811de.1579027433.git.gitgitgadget@gmail.com> In-Reply-To: References: From: "Johannes Schindelin via GitGitGadget" Date: Tue, 14 Jan 2020 18:43:49 +0000 Subject: [PATCH v4 06/10] 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 , 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