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2021-10-06terminal: teach git how to save/restore its terminal settingsLibravatar Carlo Marcelo Arenas Belón1-15/+60
Currently, git will share its console with all its children (unless they create their own), and is therefore possible that any of them that might change the settings for it could affect its operations once completed. Refactor the platform specific functionality to save the terminal settings and expand it to also do so for the output handler. This will allow for the state of the terminal to be saved and restored around a child that might misbehave (ex vi) which will be implemented next. Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28strvec: convert more callers away from argv_array nameLibravatar Jeff King1-9/+9
We eventually want to drop the argv_array name and just use strvec consistently. There's no particular reason we have to do it all at once, or care about interactions between converted and unconverted bits. Because of our preprocessor compat layer, the names are interchangeable to the compiler (so even a definition and declaration using different names is OK). This patch converts remaining files from the first half of the alphabet, to keep the diff to a manageable size. The conversion was done purely mechanically with: git ls-files '*.c' '*.h' | xargs perl -i -pe ' s/ARGV_ARRAY/STRVEC/g; s/argv_array/strvec/g; ' and then selectively staging files with "git add '[abcdefghjkl]*'". We'll deal with any indentation/style fallouts separately. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15built-in add -p: handle Escape sequences more efficientlyLibravatar Johannes Schindelin1-1/+72
When `interactive.singlekey = true`, we react immediately to keystrokes, even to Escape sequences (e.g. when pressing a cursor key). The problem with Escape sequences is that we do not really know when they are done, and as a heuristic we poll standard input for half a second to make sure that we got all of it. While waiting half a second is not asking for a whole lot, it can become quite annoying over time, therefore with this patch, we read the terminal capabilities (if available) and extract known Escape sequences from there, then stop polling immediately when we detected that the user pressed a key that generated such a known sequence. This recapitulates the remaining part of b5cc003253c8 (add -i: ignore terminal escape sequences, 2011-05-17). Note: We do *not* query the terminal capabilities directly. That would either require a lot of platform-specific code, or it would require linking to a library such as ncurses. Linking to a library in the built-ins is something we try very hard to avoid (we even kicked the libcurl dependency to a non-built-in remote helper, just to shave off a tiny fraction of a second from Git's startup time). And the platform-specific code would be a maintenance nightmare. Even worse: in Git for Windows' case, we would need to query MSYS2 pseudo terminals, which `git.exe` simply cannot do (because it is intentionally *not* an MSYS2 program). To address this, we simply spawn `infocmp -L -1` and parse its output (which works even in Git for Windows, because that helper is included in the end-user facing installations). This is done only once, as in the Perl version, but it is done only when the first Escape sequence is encountered, not upon startup of `git add -i`; This saves on startup time, yet makes reacting to the first Escape sequence slightly more sluggish. But it allows us to keep the terminal-related code encapsulated in the `compat/terminal.c` file. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15built-in add -p: handle Escape sequences in interactive.singlekey modeLibravatar Johannes Schindelin1-1/+55
This recapitulates part of b5cc003253c8 (add -i: ignore terminal escape sequences, 2011-05-17): add -i: ignore terminal escape sequences On the author's terminal, the up-arrow input sequence is ^[[A, and thus fat-fingering an up-arrow into 'git checkout -p' is quite dangerous: git-add--interactive.perl will ignore the ^[ and [ characters and happily treat A as "discard everything". As a band-aid fix, use Term::Cap to get all terminal capabilities. Then use the heuristic that any capability value that starts with ^[ (i.e., \e in perl) must be a key input sequence. Finally, given an input that starts with ^[, read more characters until we have read a full escape sequence, then return that to the caller. We use a timeout of 0.5 seconds on the subsequent reads to avoid getting stuck if the user actually input a lone ^[. Since none of the currently recognized keys start with ^[, the net result is that the sequence as a whole will be ignored and the help displayed. Note that we leave part for later which uses "Term::Cap to get all terminal capabilities", for several reasons: 1. it is actually not really necessary, as the timeout of 0.5 seconds should be plenty sufficient to catch Escape sequences, 2. it is cleaner to keep the change to special-case Escape sequences separate from the change that reads all terminal capabilities to speed things up, and 3. in practice, relying on the terminal capabilities is a bit overrated, as the information could be incomplete, or plain wrong. For example, in this developer's tmux sessions, the terminal capabilities claim that the "cursor up" sequence is ^[M, but the actual sequence produced by the "cursor up" key is ^[[A. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15terminal: add a new function to read a single keystrokeLibravatar Johannes Schindelin1-0/+55
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 <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15terminal: accommodate Git for Windows' default terminalLibravatar Johannes Schindelin1-0/+50
Git for Windows' Git Bash runs in MinTTY by default, which does not have a Win32 Console instance, but uses MSYS2 pseudo terminals instead. This is a problem, as Git for Windows does not want to use the MSYS2 emulation layer for Git itself, and therefore has no direct way to interact with that pseudo terminal. As a workaround, use the `stty` utility (which is included in Git for Windows, and which *is* an MSYS2 program, so it knows how to deal with the pseudo terminal). Note: If Git runs in a regular CMD or PowerShell window, there *is* a regular Win32 Console to work with. This is not a problem for the MSYS2 `stty`: it copes with this scenario just fine. Also note that we introduce support for more bits than would be necessary for a mere `disable_echo()` here, in preparation for the upcoming `enable_non_canonical()` function. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15terminal: make the code of disable_echo() reusableLibravatar Johannes Schindelin1-4/+15
We are about to introduce the function `enable_non_canonical()`, which shares almost the complete code with `disable_echo()`. Let's prepare for that, by refactoring out that shared code. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-15strbuf: introduce strbuf_getline_{lf,nul}()Libravatar Junio C Hamano1-1/+1
The strbuf_getline() interface allows a byte other than LF or NUL as the line terminator, but this is only because I wrote these codepaths anticipating that there might be a value other than NUL and LF that could be useful when I introduced line_termination long time ago. No useful caller that uses other value has emerged. By now, it is clear that the interface is overly broad without a good reason. Many codepaths have hardcoded preference to read either LF terminated or NUL terminated records from their input, and then call strbuf_getline() with LF or NUL as the third parameter. This step introduces two thin wrappers around strbuf_getline(), namely, strbuf_getline_lf() and strbuf_getline_nul(), and mechanically rewrites these call sites to call either one of them. The changes contained in this patch are: * introduction of these two functions in strbuf.[ch] * mechanical conversion of all callers to strbuf_getline() with either '\n' or '\0' as the third parameter to instead call the respective thin wrapper. After this step, output from "git grep 'strbuf_getline('" would become a lot smaller. An interim goal of this series is to make this an empty set, so that we can have strbuf_getline_crlf() take over the shorter name strbuf_getline(). Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-08mingw: rename WIN32 cpp macro to GIT_WINDOWS_NATIVELibravatar Jonathan Nieder1-2/+2
Throughout git, it is assumed that the WIN32 preprocessor symbol is defined on native Windows setups (mingw and msvc) and not on Cygwin. On Cygwin, most of the time git can pretend this is just another Unix machine, and Windows-specific magic is generally counterproductive. Unfortunately Cygwin *does* define the WIN32 symbol in some headers. Best to rely on a new git-specific symbol GIT_WINDOWS_NATIVE instead, defined as follows: #if defined(WIN32) && !defined(__CYGWIN__) # define GIT_WINDOWS_NATIVE #endif After this change, it should be possible to drop the CYGWIN_V15_WIN32API setting without any negative effect. [rj: %s/WINDOWS_NATIVE/GIT_WINDOWS_NATIVE/g ] Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-04mingw: reuse tty-version of git_terminal_promptLibravatar Erik Faye-Lund1-9/+60
The getpass-implementation we use on Windows isn't at all ideal; it works in raw-mode (as opposed to cooked mode), and as a result does not deal correcly with deletion, arrow-keys etc. Instead, use cooked mode to read a line at the time, allowing the C run-time to process the input properly. Since we set files to be opened in binary-mode by default on Windows, introduce a FORCE_TEXT macro that expands to the "t" modifier that forces the terminal to be opened in text-mode so we do not have to deal with CRLF issues. Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-04compat/terminal: separate input and output handlesLibravatar Erik Faye-Lund1-11/+18
On Windows, the terminal cannot be opened in read-write mode, so we need distinct pairs for reading and writing. Since this works fine on other platforms as well, always open them in pairs. Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-04compat/terminal: factor out echo-disablingLibravatar Erik Faye-Lund1-18/+25
By moving the echo-disabling code to a separate function, we can implement OS-specific versions of it for non-POSIX platforms. Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-06terminal: seek when switching between reading and writingLibravatar Jeff King1-0/+1
When a stdio stream is opened in update mode (e.g., "w+"), the C standard forbids switching between reading or writing without an intervening positioning function. Many implementations are lenient about this, but Solaris libc will flush the recently-read contents to the output buffer. In this instance, that meant writing the non-echoed password that the user just typed to the terminal. Fix it by inserting a no-op fseek between the read and write. The opposite direction (writing followed by reading) is also disallowed, but our intervening fflush is an acceptable positioning function for that alternative. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-12-12add generic terminal prompt functionLibravatar Jeff King1-0/+81
When we need to prompt the user for input interactively, we want to access their terminal directly. We can't rely on stdio because it may be connected to pipes or files, rather than the terminal. Instead, we use "getpass()", because it abstracts the idea of prompting and reading from the terminal. However, it has some problems: 1. It never echoes the typed characters, which makes it OK for passwords but annoying for other input (like usernames). 2. Some implementations of getpass() have an extremely small input buffer (e.g., Solaris 8 is reported to support only 8 characters). 3. Some implementations of getpass() will fall back to reading from stdin (e.g., glibc). We explicitly don't want this, because our stdin may be connected to a pipe speaking a particular protocol, and reading will disrupt the protocol flow (e.g., the remote-curl helper). 4. Some implementations of getpass() turn off signals, so that hitting "^C" on the terminal does not break out of the password prompt. This can be a mild annoyance. Instead, let's provide an abstract "git_terminal_prompt" function that addresses these concerns. This patch includes an implementation based on /dev/tty, enabled by setting HAVE_DEV_TTY. The fallback is to use getpass() as before. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>