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Shell: Include some metadata in parsed tokens and ask for continuation

This patchset adds some metadata to Parser::parse() which allows the
Shell to ask for the rest of a command, if it is not complete.
A command is considered complete if it has no trailing pipe, or
unterminated string.
This commit is contained in:
AnotherTest 2020-05-10 10:35:23 +04:30 committed by Andreas Kling
parent 2ac3d33c63
commit a862c230b1
3 changed files with 214 additions and 81 deletions

View file

@ -29,7 +29,7 @@
#include <stdio.h>
#include <unistd.h>
void Parser::commit_token(AllowEmptyToken allow_empty)
void Parser::commit_token(Token::Type type, AllowEmptyToken allow_empty)
{
if (allow_empty == AllowEmptyToken::No && m_token.is_empty())
return;
@ -38,7 +38,7 @@ void Parser::commit_token(AllowEmptyToken allow_empty)
m_token.clear_with_capacity();
return;
}
m_tokens.append(String::copy(m_token));
m_tokens.append({ String::copy(m_token), m_position, m_token.size(), type });
m_token.clear_with_capacity();
};
@ -82,22 +82,22 @@ bool Parser::in_state(State state) const
Vector<Command> Parser::parse()
{
for (size_t i = 0; i < m_input.length(); ++i) {
for (size_t i = 0; i < m_input.length(); ++i, m_position = i) {
char ch = m_input.characters()[i];
switch (state()) {
case State::Free:
if (ch == ' ') {
commit_token();
commit_token(Token::Bare);
break;
}
if (ch == ';') {
commit_token();
commit_token(Token::Special);
commit_subcommand();
commit_command();
break;
}
if (ch == '|') {
commit_token();
commit_token(Token::Special);
if (m_tokens.is_empty()) {
fprintf(stderr, "Syntax error: Nothing before pipe (|)\n");
return {};
@ -106,7 +106,7 @@ Vector<Command> Parser::parse()
break;
}
if (ch == '>') {
commit_token();
commit_token(Token::Special);
begin_redirect_write(STDOUT_FILENO);
// Search for another > for append.
@ -114,7 +114,7 @@ Vector<Command> Parser::parse()
break;
}
if (ch == '<') {
commit_token();
commit_token(Token::Special);
begin_redirect_read(STDIN_FILENO);
push_state(State::InRedirectionPath);
break;
@ -163,7 +163,7 @@ Vector<Command> Parser::parse()
}
if (is_multi_fd_redirection) {
commit_token();
commit_token(Token::Special);
int fd = atoi(&m_input.characters()[i + 1]);
@ -186,7 +186,7 @@ Vector<Command> Parser::parse()
if (i != m_input.length() - 1) {
char next_ch = m_input.characters()[i + 1];
if (next_ch == '>') {
commit_token();
commit_token(Token::Special);
begin_redirect_write(ch - '0');
++i;
@ -195,7 +195,7 @@ Vector<Command> Parser::parse()
break;
}
if (next_ch == '<') {
commit_token();
commit_token(Token::Special);
begin_redirect_read(ch - '0');
++i;
@ -208,7 +208,7 @@ Vector<Command> Parser::parse()
break;
case State::InWriteAppendOrRedirectionPath:
if (ch == '>') {
commit_token();
commit_token(Token::Special);
pop_state();
push_state(State::InRedirectionPath);
ASSERT(m_redirections.size());
@ -222,21 +222,21 @@ Vector<Command> Parser::parse()
[[fallthrough]];
case State::InRedirectionPath:
if (ch == '<') {
commit_token();
commit_token(Token::Special);
begin_redirect_read(STDIN_FILENO);
pop_state();
push_state(State::InRedirectionPath);
break;
}
if (ch == '>') {
commit_token();
commit_token(Token::Special);
begin_redirect_read(STDOUT_FILENO);
pop_state();
push_state(State::InRedirectionPath);
break;
}
if (ch == '|') {
commit_token();
commit_token(Token::Special);
if (m_tokens.is_empty()) {
fprintf(stderr, "Syntax error: Nothing before pipe (|)\n");
return {};
@ -260,7 +260,7 @@ Vector<Command> Parser::parse()
case State::InSingleQuotes:
if (ch == '\'') {
if (!in_state(State::InRedirectionPath))
commit_token(AllowEmptyToken::Yes);
commit_token(Token::SingleQuoted, AllowEmptyToken::Yes);
pop_state();
break;
}
@ -269,7 +269,7 @@ Vector<Command> Parser::parse()
case State::InDoubleQuotes:
if (ch == '\"') {
if (!in_state(State::InRedirectionPath))
commit_token(AllowEmptyToken::Yes);
commit_token(Token::DoubleQuoted, AllowEmptyToken::Yes);
pop_state();
break;
}
@ -294,15 +294,18 @@ Vector<Command> Parser::parse()
}
while (m_state_stack.size() > 1) {
auto allow_empty = AllowEmptyToken::No;
if (state() == State::InDoubleQuotes || state() == State::InSingleQuotes)
allow_empty = AllowEmptyToken::Yes;
commit_token(allow_empty);
if (state() == State::InDoubleQuotes) {
commit_token(Token::UnterminatedDoubleQuoted, AllowEmptyToken::Yes);
} else if (state() == State::InSingleQuotes) {
commit_token(Token::UnterminatedSingleQuoted, AllowEmptyToken::Yes);
} else {
commit_token(Token::Bare, AllowEmptyToken::No);
}
pop_state();
}
ASSERT(state() == State::Free);
commit_token();
commit_token(Token::Bare);
commit_subcommand();
commit_command();

View file

@ -29,6 +29,21 @@
#include <AK/String.h>
#include <AK/Vector.h>
struct Token {
enum Type {
Bare,
SingleQuoted,
DoubleQuoted,
UnterminatedSingleQuoted,
UnterminatedDoubleQuoted,
Special,
};
String text;
size_t end;
size_t length;
Type type;
};
struct Redirection {
enum Type {
Pipe,
@ -48,7 +63,7 @@ struct Rewiring {
};
struct Subcommand {
Vector<String> args;
Vector<Token> args;
Vector<Redirection> redirections;
Vector<Rewiring> rewirings;
};
@ -71,7 +86,7 @@ private:
No,
Yes,
};
void commit_token(AllowEmptyToken = AllowEmptyToken::No);
void commit_token(Token::Type, AllowEmptyToken = AllowEmptyToken::No);
void commit_subcommand();
void commit_command();
void do_pipe();
@ -105,7 +120,8 @@ private:
Vector<Command> m_commands;
Vector<Subcommand> m_subcommands;
Vector<String> m_tokens;
Vector<Token> m_tokens;
Vector<Redirection> m_redirections;
Vector<char> m_token;
size_t m_position { 0 };
};

View file

@ -53,11 +53,42 @@
GlobalState g;
static Line::Editor editor { Line::Configuration { Line::Configuration::UnescapedSpaces } };
static int run_command(const String&);
struct ExitCodeOrContinuationRequest {
enum ContinuationRequest {
Nothing,
Pipe,
DoubleQuotedString,
SingleQuotedString,
};
ExitCodeOrContinuationRequest(ContinuationRequest continuation)
: continuation(continuation)
{
}
ExitCodeOrContinuationRequest(int exit)
: exit_code(exit)
{
}
bool has_value() const { return exit_code.has_value(); }
int value() const
{
ASSERT(has_value());
return exit_code.value();
}
Optional<int> exit_code;
ContinuationRequest continuation { Nothing };
};
static ExitCodeOrContinuationRequest run_command(const StringView&);
void cache_path();
static ExitCodeOrContinuationRequest::ContinuationRequest s_should_continue { ExitCodeOrContinuationRequest::Nothing };
static String prompt()
{
auto build_prompt = []() -> String {
auto* ps1 = getenv("PROMPT");
if (!ps1) {
if (g.uid == 0)
@ -110,6 +141,25 @@ static String prompt()
builder.append(*ptr);
}
return builder.to_string();
};
auto the_prompt = build_prompt();
auto prompt_length = editor.actual_rendered_string_length(the_prompt);
if (s_should_continue != ExitCodeOrContinuationRequest::Nothing) {
const auto format_string = "\033[34m%.*-s\033[m";
switch (s_should_continue) {
case ExitCodeOrContinuationRequest::Pipe:
return String::format(format_string, prompt_length, "pipe> ");
case ExitCodeOrContinuationRequest::DoubleQuotedString:
return String::format(format_string, prompt_length, "dquote> ");
case ExitCodeOrContinuationRequest::SingleQuotedString:
return String::format(format_string, prompt_length, "squote> ");
default:
break;
}
}
return the_prompt;
}
static int sh_pwd(int, const char**)
@ -306,9 +356,13 @@ static int sh_time(int argc, const char** argv)
}
Core::ElapsedTimer timer;
timer.start();
int exit_code = run_command(builder.to_string());
auto exit_code = run_command(builder.string_view());
if (!exit_code.has_value()) {
printf("Shell: Incomplete command: %s\n", builder.to_string().characters());
exit_code = 1;
}
printf("Time: %d ms\n", timer.elapsed());
return exit_code;
return exit_code.value();
}
static int sh_umask(int argc, const char** argv)
@ -581,7 +635,7 @@ static bool handle_builtin(int argc, const char** argv, int& retval)
class FileDescriptionCollector {
public:
FileDescriptionCollector() {}
FileDescriptionCollector() { }
~FileDescriptionCollector() { collect(); }
void collect()
@ -724,13 +778,13 @@ static Vector<String> expand_parameters(const StringView& param)
return res;
}
static Vector<String> process_arguments(const Vector<String>& args)
static Vector<String> process_arguments(const Vector<Token>& args)
{
Vector<String> argv_string;
for (auto& arg : args) {
// This will return the text passed in if it wasn't a variable
// This lets us just loop over its values
auto expanded_parameters = expand_parameters(arg);
auto expanded_parameters = expand_parameters(arg.text);
for (auto& exp_arg : expanded_parameters) {
if (exp_arg.starts_with('~'))
@ -748,7 +802,29 @@ static Vector<String> process_arguments(const Vector<String>& args)
return argv_string;
}
static int run_command(const String& cmd)
static ExitCodeOrContinuationRequest::ContinuationRequest is_complete(const Vector<Command>& commands)
{
// check if the last command ends with a pipe, or an unterminated string
auto& last_command = commands.last();
auto& subcommands = last_command.subcommands;
if (subcommands.size() == 0)
return ExitCodeOrContinuationRequest::Nothing;
auto& last_subcommand = subcommands.last();
if (!last_subcommand.redirections.find([](auto& redirection) { return redirection.type == Redirection::Pipe; }).is_end())
return ExitCodeOrContinuationRequest::Pipe;
if (!last_subcommand.args.find([](auto& token) { return token.type == Token::UnterminatedSingleQuoted; }).is_end())
return ExitCodeOrContinuationRequest::SingleQuotedString;
if (!last_subcommand.args.find([](auto& token) { return token.type == Token::UnterminatedDoubleQuoted; }).is_end())
return ExitCodeOrContinuationRequest::DoubleQuotedString;
return ExitCodeOrContinuationRequest::Nothing;
}
static ExitCodeOrContinuationRequest run_command(const StringView& cmd)
{
if (cmd.is_empty())
return 0;
@ -758,13 +834,36 @@ static int run_command(const String& cmd)
auto commands = Parser(cmd).parse();
auto needs_more = is_complete(commands);
if (needs_more != ExitCodeOrContinuationRequest::Nothing)
return needs_more;
#ifdef SH_DEBUG
for (auto& command : commands) {
for (size_t i = 0; i < command.subcommands.size(); ++i) {
for (size_t j = 0; j < i; ++j)
dbgprintf(" ");
for (auto& arg : command.subcommands[i].args) {
dbgprintf("<%s> ", arg.characters());
switch (arg.type) {
case Token::Bare:
dbgprintf("<%s> ", arg.text.characters());
break;
case Token::SingleQuoted:
dbgprintf("'<%s>' ", arg.text.characters());
break;
case Token::DoubleQuoted:
dbgprintf("\"<%s>\" ", arg.text.characters());
break;
case Token::UnterminatedSingleQuoted:
dbgprintf("\'<%s> ", arg.text.characters());
break;
case Token::UnterminatedDoubleQuoted:
dbgprintf("\"<%s> ", arg.text.characters());
break;
case Token::Special:
dbgprintf("<%s> ", arg.text.characters());
break;
}
}
dbgprintf("\n");
for (auto& redirecton : command.subcommands[i].redirections) {
@ -1320,12 +1419,27 @@ int main(int argc, char** argv)
cache_path();
StringBuilder complete_line_builder;
for (;;) {
auto line = editor.get_line(prompt());
if (line.is_empty())
continue;
run_command(line);
editor.add_to_history(line);
// FIXME: This might be a bit counter-intuitive, since we put nothing
// between the two lines, even though the user has pressed enter
// but since the LineEditor cannot yet handle literal newlines
// inside the text, we opt to do this the wrong way (for the time being)
complete_line_builder.append(line);
auto complete_or_exit_code = run_command(complete_line_builder.string_view());
s_should_continue = complete_or_exit_code.continuation;
if (!complete_or_exit_code.has_value())
continue;
editor.add_to_history(complete_line_builder.build());
complete_line_builder.clear();
}
return 0;