// A small utility to print information related to pressing keys. This is similar to using tools
// like `xxd` and `od -tx1z` but provides more information such as the time delay between each
// character. It also allows pressing and interpreting keys that are normally special such as
// [ctrl-C] (interrupt the program) or [ctrl-D] (EOF to signal the program should exit).
// And unlike those other tools this one disables ICRNL mode so it can distinguish between
// carriage-return (\cM) and newline (\cJ).
//
// Type "exit" or "quit" to terminate the program.
#include "config.h" // IWYU pragma: keep
#include <errno.h>
#include <getopt.h>
#include <signal.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include <cstring>
#include <cwchar>
#include <memory>
#include <string>
#include <vector>
#include "common.h"
#include "env.h"
#include "fallback.h" // IWYU pragma: keep
#include "fish_version.h"
#include "input.h"
#include "input_common.h"
#include "parser.h"
#include "print_help.h"
#include "proc.h"
#include "reader.h"
#include "signal.h"
#include "wutil.h" // IWYU pragma: keep
struct config_paths_t determine_config_directory_paths(const char *argv0);
static const wchar_t *ctrl_symbolic_names[] = {
nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, L"\\a",
L"\\b", L"\\t", L"\\n", L"\\v", L"\\f", L"\\r", nullptr, nullptr,
nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
nullptr, nullptr, nullptr, L"\\e", nullptr, nullptr, nullptr, nullptr};
/// Return true if the recent sequence of characters indicates the user wants to exit the program.
static bool should_exit(wchar_t wc) {
unsigned char c = wc < 0x80 ? wc : 0;
static unsigned char recent_chars[4] = {0};
recent_chars[0] = recent_chars[1];
recent_chars[1] = recent_chars[2];
recent_chars[2] = recent_chars[3];
recent_chars[3] = c;
if (c == shell_modes.c_cc[VINTR]) {
if (recent_chars[2] == shell_modes.c_cc[VINTR]) return true;
std::fwprintf(stderr, L"Press [ctrl-%c] again to exit\n", shell_modes.c_cc[VINTR] + 0x40);
return false;
}
if (c == shell_modes.c_cc[VEOF]) {
if (recent_chars[2] == shell_modes.c_cc[VEOF]) return true;
std::fwprintf(stderr, L"Press [ctrl-%c] again to exit\n", shell_modes.c_cc[VEOF] + 0x40);
return false;
}
return std::memcmp(recent_chars, "exit", const_strlen("exit")) == 0 ||
std::memcmp(recent_chars, "quit", const_strlen("quit")) == 0;
}
/// Return the name if the recent sequence of characters matches a known terminfo sequence.
static maybe_t<wcstring> sequence_name(wchar_t wc) {
static std::string recent_chars;
if (wc >= 0x80) {
// Terminfo sequences are always ASCII.
recent_chars.clear();
return none();
}
unsigned char c = wc;
recent_chars.push_back(c);
while (recent_chars.size() > 8) {
recent_chars.erase(recent_chars.begin());
}
// Check all nonempty substrings extending to the end.
for (size_t i = 0; i < recent_chars.size(); i++) {
wcstring out_name;
wcstring seq = str2wcstring(recent_chars.substr(i));
if (input_terminfo_get_name(seq, &out_name)) {
return out_name;
}
}
return none();
}
/// Return true if the character must be escaped when used in the sequence of chars to be bound in
/// a `bind` command.
static bool must_escape(wchar_t wc) { return std::wcschr(L"[]()<>{}*\\?$#;&|'\"", wc) != nullptr; }
static void ctrl_to_symbol(wchar_t *buf, int buf_len, wchar_t wc, bool bind_friendly) {
if (ctrl_symbolic_names[wc]) {
if (bind_friendly) {
std::swprintf(buf, buf_len, L"%ls", ctrl_symbolic_names[wc]);
} else {
std::swprintf(buf, buf_len, L"\\c%c (or %ls)", wc + 0x40, ctrl_symbolic_names[wc]);
}
} else {
std::swprintf(buf, buf_len, L"\\c%c", wc + 0x40);
}
}
static void space_to_symbol(wchar_t *buf, int buf_len, wchar_t wc, bool bind_friendly) {
if (bind_friendly) {
std::swprintf(buf, buf_len, L"\\x%X", wc);
} else {
std::swprintf(buf, buf_len, L"\\x%X (aka \"space\")", wc);
}
}
static void del_to_symbol(wchar_t *buf, int buf_len, wchar_t wc, bool bind_friendly) {
if (bind_friendly) {
std::swprintf(buf, buf_len, L"\\x%X", wc);
} else {
std::swprintf(buf, buf_len, L"\\x%X (aka \"del\")", wc);
}
}
static void ascii_printable_to_symbol(wchar_t *buf, int buf_len, wchar_t wc, bool bind_friendly) {
if (bind_friendly && must_escape(wc)) {
std::swprintf(buf, buf_len, L"\\%c", wc);
} else {
std::swprintf(buf, buf_len, L"%c", wc);
}
}
/// Convert a wide-char to a symbol that can be used in our output. The use of a static buffer
/// requires that the returned string be used before we are called again.
static wchar_t *char_to_symbol(wchar_t wc, bool bind_friendly) {
static wchar_t buf[64];
if (wc < L' ') { // ASCII control character
ctrl_to_symbol(buf, sizeof(buf) / sizeof(*buf), wc, bind_friendly);
} else if (wc == L' ') { // the "space" character
space_to_symbol(buf, sizeof(buf) / sizeof(*buf), wc, bind_friendly);
} else if (wc == 0x7F) { // the "del" character
del_to_symbol(buf, sizeof(buf) / sizeof(*buf), wc, bind_friendly);
} else if (wc < 0x80) { // ASCII characters that are not control characters
ascii_printable_to_symbol(buf, sizeof(buf) / sizeof(*buf), wc, bind_friendly);
}
// Conditional handling of BMP Unicode characters depends on the encoding. Assume width of wchar_t
// corresponds to the encoding, i.e. WCHAR_T_BITS == 16 implies UTF-16 and WCHAR_T_BITS == 32
// because there's no other sane way of handling the input.
#if WCHAR_T_BITS == 16
else if (wc <= 0xD7FF || (wc >= 0xE000 && wc <= 0xFFFD)) {
// UTF-16 encoding of Unicode character in BMP range
std::swprintf(buf, sizeof(buf) / sizeof(*buf), L"\\u%04X", wc);
} else {
// Our support for UTF-16 surrogate pairs is non-existent.
// See https://github.com/fish-shell/fish-shell/issues/6585#issuecomment-783669903 for what
// correct handling of surrogate pairs would look like - except it would need to be done
// everywhere.
// 0xFFFD is the unicode codepoint for "symbol doesn't exist in codepage" and is the most
// correct thing we can do given the byte-by-byte parsing without any support for surrogate
// pairs.
std::swprintf(buf, sizeof(buf) / sizeof(*buf), L"\\uFFFD");
}
#elif WCHAR_T_BITS == 32
else if (wc <= 0xFFFF) { // BMP Unicode chararacter
std::swprintf(buf, sizeof(buf) / sizeof(*buf), L"\\u%04X", wc);
} else { // Non-BMP Unicode chararacter
std::swprintf(buf, sizeof(buf) / sizeof(*buf), L"\\U%06X", wc);
}
#else
static_assert(false, "Unsupported WCHAR_T size; unknown encoding!");
#endif
return buf;
}
static void add_char_to_bind_command(wchar_t wc, std::vector<wchar_t> &bind_chars) {
bind_chars.push_back(wc);
}
static void output_bind_command(std::vector<wchar_t> &bind_chars) {
if (!bind_chars.empty()) {
std::fputws(L"bind ", stdout);
for (auto bind_char : bind_chars) {
std::fputws(char_to_symbol(bind_char, true), stdout);
}
std::fputws(L" 'do something'\n", stdout);
bind_chars.clear();
}
}
static void output_info_about_char(wchar_t wc) {
std::fwprintf(stderr, L"hex: %4X char: %ls\n", wc, char_to_symbol(wc, false));
}
static bool output_matching_key_name(wchar_t wc) {
if (maybe_t<wcstring> name = sequence_name(wc)) {
std::fwprintf(stdout, L"bind -k %ls 'do something'\n", name->c_str());
return true;
}
return false;
}
static double output_elapsed_time(double prev_tstamp, bool first_char_seen) {
// How much time has passed since the previous char was received in microseconds.
double now = timef();
long long int delta_tstamp_us = 1000000 * (now - prev_tstamp);
if (delta_tstamp_us >= 200000 && first_char_seen) std::fputwc(L'\n', stderr);
if (delta_tstamp_us >= 1000000) {
std::fwprintf(stderr, L" ");
} else {
std::fwprintf(stderr, L"(%3lld.%03lld ms) ", delta_tstamp_us / 1000,
delta_tstamp_us % 1000);
}
return now;
}
/// Process the characters we receive as the user presses keys.
static void process_input(bool continuous_mode) {
bool first_char_seen = false;
double prev_tstamp = 0.0;
input_event_queue_t queue;
std::vector<wchar_t> bind_chars;
std::fwprintf(stderr, L"Press a key:\n");
for (;;) {
char_event_t evt{0};
if (reader_test_and_clear_interrupted()) {
evt = char_event_t{shell_modes.c_cc[VINTR]};
} else {
evt = queue.readch_timed(true);
}
if (!evt.is_char()) {
output_bind_command(bind_chars);
if (first_char_seen && !continuous_mode) {
return;
}
continue;
}
wchar_t wc = evt.get_char();
prev_tstamp = output_elapsed_time(prev_tstamp, first_char_seen);
// Hack for #3189. Do not suggest \c@ as the binding for nul, because a string containing
// nul cannot be passed to builtin_bind since it uses C strings. We'll output the name of
// this key (nul) elsewhere.
if (wc) {
add_char_to_bind_command(wc, bind_chars);
}
output_info_about_char(wc);
if (output_matching_key_name(wc)) {
output_bind_command(bind_chars);
}
if (should_exit(wc)) {
std::fwprintf(stderr, L"\nExiting at your request.\n");
break;
}
first_char_seen = true;
}
}
/// Setup our environment (e.g., tty modes), process key strokes, then reset the environment.
[[noreturn]] static void setup_and_process_keys(bool continuous_mode) {
set_interactive_session(true);
set_main_thread();
setup_fork_guards();
env_init();
reader_init();
parser_t &parser = parser_t::principal_parser();
scoped_push<bool> interactive{&parser.libdata().is_interactive, true};
signal_set_handlers(true);
// We need to set the shell-modes for ICRNL,
// in fish-proper this is done once a command is run.
tcsetattr(STDIN_FILENO, TCSANOW, &shell_modes);
if (continuous_mode) {
std::fwprintf(stderr, L"\n");
std::fwprintf(stderr,
L"To terminate this program type \"exit\" or \"quit\" in this window,\n");
std::fwprintf(stderr, L"or press [ctrl-%c] or [ctrl-%c] twice in a row.\n",
shell_modes.c_cc[VINTR] + 0x40, shell_modes.c_cc[VEOF] + 0x40);
std::fwprintf(stderr, L"\n");
}
process_input(continuous_mode);
restore_term_mode();
_exit(0);
}
static bool parse_flags(int argc, char **argv, bool *continuous_mode) {
const char *short_opts = "+chv";
const struct option long_opts[] = {{"continuous", no_argument, nullptr, 'c'},
{"help", no_argument, nullptr, 'h'},
{"version", no_argument, nullptr, 'v'},
{nullptr, 0, nullptr, 0}};
int opt;
bool error = false;
while (!error && (opt = getopt_long(argc, argv, short_opts, long_opts, nullptr)) != -1) {
switch (opt) {
case 'c': {
*continuous_mode = true;
break;
}
case 'h': {
print_help("fish_key_reader", 1);
exit(0);
}
case 'v': {
std::fwprintf(stdout, _(L"%ls, version %s\n"), program_name, get_fish_version());
exit(0);
}
default: {
// We assume getopt_long() has already emitted a diagnostic msg.
error = true;
break;
}
}
}
if (error) return false;
argc -= optind;
if (argc != 0) {
std::fwprintf(stderr, L"Expected no arguments, got %d\n", argc);
return false;
}
return true;
}
int main(int argc, char **argv) {
program_name = L"fish_key_reader";
bool continuous_mode = false;
if (!parse_flags(argc, argv, &continuous_mode)) return 1;
if (!isatty(STDIN_FILENO)) {
std::fwprintf(stderr, L"Stdin must be attached to a tty.\n");
return 1;
}
setup_and_process_keys(continuous_mode);
exit_without_destructors(0);
return EXIT_FAILURE; // above should exit
}