git/compat/terminal.h

#ifndef COMPAT_TERMINAL_H
#define COMPAT_TERMINAL_H

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 */
add generic terminal prompt function 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> 2011-12-10 10:41:01 +00:00			`#ifndef COMPAT_TERMINAL_H`
			`#define COMPAT_TERMINAL_H`

			`char git_terminal_prompt(const char prompt, int echo);`

terminal: add a new function to read a single keystroke 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> 2020-01-14 18:43:49 +00:00			`/* Read a single keystroke, without echoing it to the terminal */`
			`int read_key_without_echo(struct strbuf *buf);`

add generic terminal prompt function 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> 2011-12-10 10:41:01 +00:00			`#endif /* COMPAT_TERMINAL_H */`