ladybird/Shell/LineEditor.cpp
Andreas Kling 686ade6b5a AK: Make quick_sort() a little more ergonomic
Now it actually defaults to "a < b" comparison, instead of forcing you
to provide a trivial less-than comparator. Also you can pass in any
collection type that has .begin() and .end() and we'll sort it for you.
2020-03-03 16:02:58 +01:00

561 lines
19 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "LineEditor.h"
#include "GlobalState.h"
#include <ctype.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <unistd.h>
LineEditor::LineEditor()
{
struct winsize ws;
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) < 0)
m_num_columns = 80;
else
m_num_columns = ws.ws_col;
}
LineEditor::~LineEditor()
{
}
void LineEditor::add_to_history(const String& line)
{
if ((m_history.size() + 1) > m_history_capacity)
m_history.take_first();
m_history.append(line);
}
void LineEditor::clear_line()
{
for (size_t i = 0; i < m_cursor; ++i)
fputc(0x8, stdout);
fputs("\033[K", stdout);
fflush(stdout);
m_buffer.clear();
m_cursor = 0;
}
void LineEditor::insert(const String& string)
{
fputs(string.characters(), stdout);
fflush(stdout);
if (m_cursor == m_buffer.size()) {
m_buffer.append(string.characters(), string.length());
m_cursor = m_buffer.size();
return;
}
vt_save_cursor();
vt_clear_to_end_of_line();
for (size_t i = m_cursor; i < m_buffer.size(); ++i)
fputc(m_buffer[i], stdout);
vt_restore_cursor();
m_buffer.ensure_capacity(m_buffer.size() + string.length());
for (size_t i = 0; i < string.length(); ++i)
m_buffer.insert(m_cursor + i, string[i]);
m_cursor += string.length();
}
void LineEditor::insert(const char ch)
{
putchar(ch);
fflush(stdout);
if (m_cursor == m_buffer.size()) {
m_buffer.append(ch);
m_cursor = m_buffer.size();
return;
}
vt_save_cursor();
vt_clear_to_end_of_line();
for (size_t i = m_cursor; i < m_buffer.size(); ++i)
fputc(m_buffer[i], stdout);
vt_restore_cursor();
m_buffer.insert(m_cursor, ch);
++m_cursor;
}
void LineEditor::cache_path()
{
if (!m_path.is_empty())
m_path.clear_with_capacity();
String path = getenv("PATH");
if (path.is_empty())
return;
auto directories = path.split(':');
for (const auto& directory : directories) {
Core::DirIterator programs(directory.characters(), Core::DirIterator::SkipDots);
while (programs.has_next()) {
auto program = programs.next_path();
String program_path = String::format("%s/%s", directory.characters(), program.characters());
struct stat program_status;
int stat_error = stat(program_path.characters(), &program_status);
if (!stat_error && (program_status.st_mode & S_IXUSR))
m_path.append(program.characters());
}
}
quick_sort(m_path);
}
void LineEditor::cut_mismatching_chars(String& completion, const String& other, size_t start_compare)
{
size_t i = start_compare;
while (i < completion.length() && i < other.length() && completion[i] == other[i])
++i;
completion = completion.substring(0, i);
}
// Function returns Vector<String> as assignment is made from return value at callsite
// (instead of StringView)
Vector<String> LineEditor::tab_complete_first_token(const String& token)
{
auto match = binary_search(m_path.data(), m_path.size(), token, [](const String& token, const String& program) -> int {
return strncmp(token.characters(), program.characters(), token.length());
});
if (!match)
return Vector<String>();
String completion = *match;
Vector<String> suggestions;
// Now that we have a program name starting with our token, we look at
// other program names starting with our token and cut off any mismatching
// characters.
bool seen_others = false;
int index = match - m_path.data();
for (int i = index - 1; i >= 0 && m_path[i].starts_with(token); --i) {
suggestions.append(m_path[i]);
cut_mismatching_chars(completion, m_path[i], token.length());
seen_others = true;
}
for (size_t i = index + 1; i < m_path.size() && m_path[i].starts_with(token); ++i) {
cut_mismatching_chars(completion, m_path[i], token.length());
suggestions.append(m_path[i]);
seen_others = true;
}
suggestions.append(m_path[index]);
// If we have characters to add, add them.
if (completion.length() > token.length())
insert(completion.substring(token.length(), completion.length() - token.length()));
// If we have a single match, we add a space, unless we already have one.
if (!seen_others && (m_cursor == m_buffer.size() || m_buffer[m_cursor] != ' '))
insert(' ');
return suggestions;
}
Vector<String> LineEditor::tab_complete_other_token(String& token)
{
String path;
Vector<String> suggestions;
ssize_t last_slash = token.length() - 1;
while (last_slash >= 0 && token[last_slash] != '/')
--last_slash;
if (last_slash >= 0) {
// Split on the last slash. We'll use the first part as the directory
// to search and the second part as the token to complete.
path = token.substring(0, last_slash + 1);
if (path[0] != '/')
path = String::format("%s/%s", g.cwd.characters(), path.characters());
path = canonicalized_path(path);
token = token.substring(last_slash + 1, token.length() - last_slash - 1);
} else {
// We have no slashes, so the directory to search is the current
// directory and the token to complete is just the original token.
path = g.cwd;
}
// This is a bit naughty, but necessary without reordering the loop
// below. The loop terminates early, meaning that
// the suggestions list is incomplete.
// We only do this if the token is empty though.
if (token.is_empty()) {
Core::DirIterator suggested_files(path, Core::DirIterator::SkipDots);
while (suggested_files.has_next()) {
suggestions.append(suggested_files.next_path());
}
}
String completion;
bool seen_others = false;
Core::DirIterator files(path, Core::DirIterator::SkipDots);
while (files.has_next()) {
auto file = files.next_path();
if (file.starts_with(token)) {
if (!token.is_empty())
suggestions.append(file);
if (completion.is_empty()) {
completion = file; // Will only be set once.
} else {
cut_mismatching_chars(completion, file, token.length());
if (completion.is_empty()) // We cut everything off!
return suggestions;
seen_others = true;
}
}
}
if (completion.is_empty())
return suggestions;
// If we have characters to add, add them.
if (completion.length() > token.length())
insert(completion.substring(token.length(), completion.length() - token.length()));
// If we have a single match and it's a directory, we add a slash. If it's
// a regular file, we add a space, unless we already have one.
if (!seen_others) {
String file_path = String::format("%s/%s", path.characters(), completion.characters());
struct stat program_status;
int stat_error = stat(file_path.characters(), &program_status);
if (!stat_error) {
if (S_ISDIR(program_status.st_mode))
insert('/');
else if (m_cursor == m_buffer.size() || m_buffer[m_cursor] != ' ')
insert(' ');
}
}
return {}; // Return an empty vector
}
String LineEditor::get_line(const String& prompt)
{
fputs(prompt.characters(), stdout);
fflush(stdout);
m_history_cursor = m_history.size();
m_cursor = 0;
for (;;) {
char keybuf[16];
ssize_t nread = read(0, keybuf, sizeof(keybuf));
// FIXME: exit()ing here is a bit off. Should communicate failure to caller somehow instead.
if (nread == 0)
exit(0);
if (nread < 0) {
if (errno == EINTR) {
if (g.was_interrupted) {
g.was_interrupted = false;
if (!m_buffer.is_empty())
printf("^C");
}
if (g.was_resized) {
g.was_resized = false;
printf("\033[2K\r");
m_buffer.clear();
struct winsize ws;
int rc = ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws);
ASSERT(rc == 0);
m_num_columns = ws.ws_col;
return String::empty();
}
m_buffer.clear();
putchar('\n');
return String::empty();
}
perror("read failed");
// FIXME: exit()ing here is a bit off. Should communicate failure to caller somehow instead.
exit(2);
}
auto do_delete = [&] {
if (m_cursor == m_buffer.size()) {
fputc('\a', stdout);
fflush(stdout);
return;
}
m_buffer.remove(m_cursor);
fputs("\033[3~", stdout);
fflush(stdout);
vt_save_cursor();
vt_clear_to_end_of_line();
for (size_t i = m_cursor; i < m_buffer.size(); ++i)
fputc(m_buffer[i], stdout);
vt_restore_cursor();
};
for (ssize_t i = 0; i < nread; ++i) {
char ch = keybuf[i];
if (ch == 0)
continue;
switch (m_state) {
case InputState::ExpectBracket:
if (ch == '[') {
m_state = InputState::ExpectFinal;
continue;
} else {
m_state = InputState::Free;
break;
}
case InputState::ExpectFinal:
switch (ch) {
case 'A': // up
if (m_history_cursor > 0)
--m_history_cursor;
clear_line();
if (m_history_cursor < m_history.size())
insert(m_history[m_history_cursor]);
m_state = InputState::Free;
continue;
case 'B': // down
if (m_history_cursor < m_history.size())
++m_history_cursor;
clear_line();
if (m_history_cursor < m_history.size())
insert(m_history[m_history_cursor]);
m_state = InputState::Free;
continue;
case 'D': // left
if (m_cursor > 0) {
--m_cursor;
fputs("\033[D", stdout);
fflush(stdout);
}
m_state = InputState::Free;
continue;
case 'C': // right
if (m_cursor < m_buffer.size()) {
++m_cursor;
fputs("\033[C", stdout);
fflush(stdout);
}
m_state = InputState::Free;
continue;
case 'H':
if (m_cursor > 0) {
fprintf(stdout, "\033[%zuD", m_cursor);
fflush(stdout);
m_cursor = 0;
}
m_state = InputState::Free;
continue;
case 'F':
if (m_cursor < m_buffer.size()) {
fprintf(stdout, "\033[%zuC", m_buffer.size() - m_cursor);
fflush(stdout);
m_cursor = m_buffer.size();
}
m_state = InputState::Free;
continue;
case '3':
do_delete();
m_state = InputState::ExpectTerminator;
continue;
default:
dbgprintf("Shell: Unhandled final: %b (%c)\n", ch, ch);
m_state = InputState::Free;
continue;
}
break;
case InputState::ExpectTerminator:
m_state = InputState::Free;
continue;
case InputState::Free:
if (ch == 27) {
m_state = InputState::ExpectBracket;
continue;
}
break;
}
if (ch == '\t') {
bool is_empty_token = m_cursor == 0 || m_buffer[m_cursor - 1] == ' ';
m_times_tab_pressed++;
int token_start = m_cursor - 1;
if (!is_empty_token) {
while (token_start >= 0 && m_buffer[token_start] != ' ')
--token_start;
++token_start;
}
bool is_first_token = true;
for (int i = token_start - 1; i >= 0; --i) {
if (m_buffer[i] != ' ') {
is_first_token = false;
break;
}
}
String token = is_empty_token ? String() : String(&m_buffer[token_start], m_cursor - token_start);
Vector<String> suggestions;
if (is_first_token)
suggestions = tab_complete_first_token(token);
else
suggestions = tab_complete_other_token(token);
if (m_times_tab_pressed > 1 && !suggestions.is_empty()) {
size_t longest_suggestion_length = 0;
for (auto& suggestion : suggestions)
longest_suggestion_length = max(longest_suggestion_length, suggestion.length());
size_t num_printed = 0;
putchar('\n');
for (auto& suggestion : suggestions) {
size_t next_column = num_printed + suggestion.length() + longest_suggestion_length + 2;
if (next_column > m_num_columns) {
putchar('\n');
num_printed = 0;
}
num_printed += fprintf(stderr, "%-*s", static_cast<int>(longest_suggestion_length) + 2, suggestion.characters());
}
putchar('\n');
write(STDOUT_FILENO, prompt.characters(), prompt.length());
write(STDOUT_FILENO, m_buffer.data(), m_cursor);
// Prevent not printing characters in case the user has moved the cursor and then pressed tab
write(STDOUT_FILENO, m_buffer.data() + m_cursor, m_buffer.size() - m_cursor);
m_cursor = m_buffer.size(); // bash doesn't do this, but it makes a little bit more sense
}
suggestions.clear_with_capacity();
continue;
}
m_times_tab_pressed = 0; // Safe to say if we get here, the user didn't press TAB
auto do_backspace = [&] {
if (m_cursor == 0) {
fputc('\a', stdout);
fflush(stdout);
return;
}
m_buffer.remove(m_cursor - 1);
--m_cursor;
putchar(8);
vt_save_cursor();
vt_clear_to_end_of_line();
for (size_t i = m_cursor; i < m_buffer.size(); ++i)
fputc(m_buffer[i], stdout);
vt_restore_cursor();
};
if (ch == 8 || ch == g.termios.c_cc[VERASE]) {
do_backspace();
continue;
}
if (ch == g.termios.c_cc[VWERASE]) {
bool has_seen_nonspace = false;
while (m_cursor > 0) {
if (isspace(m_buffer[m_cursor - 1])) {
if (has_seen_nonspace)
break;
} else {
has_seen_nonspace = true;
}
do_backspace();
}
continue;
}
if (ch == g.termios.c_cc[VKILL]) {
while (m_cursor > 0)
do_backspace();
continue;
}
if (ch == 0xc) { // ^L
printf("\033[3J\033[H\033[2J"); // Clear screen.
fputs(prompt.characters(), stdout);
for (size_t i = 0; i < m_buffer.size(); ++i)
fputc(m_buffer[i], stdout);
if (m_cursor < m_buffer.size())
printf("\033[%zuD", m_buffer.size() - m_cursor); // Move cursor N steps left.
fflush(stdout);
continue;
}
if (ch == 0x01) { // ^A
if (m_cursor > 0) {
printf("\033[%zuD", m_cursor);
fflush(stdout);
m_cursor = 0;
}
continue;
}
if (ch == g.termios.c_cc[VEOF]) { // Normally ^D
if (m_buffer.is_empty()) {
printf("<EOF>\n");
exit(0);
}
continue;
}
if (ch == 0x05) { // ^E
if (m_cursor < m_buffer.size()) {
printf("\033[%zuC", m_buffer.size() - m_cursor);
fflush(stdout);
m_cursor = m_buffer.size();
}
continue;
}
if (ch == '\n') {
putchar('\n');
fflush(stdout);
auto string = String::copy(m_buffer);
m_buffer.clear();
return string;
}
insert(ch);
}
}
}
void LineEditor::vt_save_cursor()
{
fputs("\033[s", stdout);
fflush(stdout);
}
void LineEditor::vt_restore_cursor()
{
fputs("\033[u", stdout);
fflush(stdout);
}
void LineEditor::vt_clear_to_end_of_line()
{
fputs("\033[K", stdout);
fflush(stdout);
}