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banan-os
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Shell: command execution and parsing support piped commands 

There is still problems with "blocking" builtin commands (time),
return value, ...
This commit is contained in:
Bananymous 2023-08-17 12:05:38 +03:00
parent dcd8374b89
commit eb98d70a0b
1 changed files with 194 additions and 58 deletions
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250
userspace/Shell/main.cpp
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@ -21,7 +21,7 @@ extern char** environ;
static const char* argv0 = nullptr; static const char* argv0 = nullptr;
static int last_return = 0; static int last_return = 0;
BAN::Vector<BAN::String> parse_command(BAN::StringView); BAN::Vector<BAN::Vector<BAN::String>> parse_command(BAN::StringView);
BAN::Optional<BAN::String> parse_dollar(BAN::StringView command, size_t& i) BAN::Optional<BAN::String> parse_dollar(BAN::StringView command, size_t& i)
{ {
@ -151,7 +151,7 @@ BAN::Optional<BAN::String> parse_dollar(BAN::StringView command, size_t& i)
return "$"sv; return "$"sv;
} }
BAN::Vector<BAN::String> parse_command(BAN::StringView command) BAN::Vector<BAN::Vector<BAN::String>> parse_command(BAN::StringView command_view)
{ {
enum class State enum class State
{ {
@ -160,13 +160,14 @@ BAN::Vector<BAN::String> parse_command(BAN::StringView command)
DoubleQuote, DoubleQuote,
}; };
BAN::Vector<BAN::String> result; BAN::Vector<BAN::Vector<BAN::String>> result;
BAN::Vector<BAN::String> command_args;
State state = State::Normal; State state = State::Normal;
BAN::String current; BAN::String current_arg;
for (size_t i = 0; i < command.size(); i++) for (size_t i = 0; i < command_view.size(); i++)
{ {
char c = command[i]; char c = command_view[i];
switch (state) switch (state)
{ {
@ -177,22 +178,31 @@ BAN::Vector<BAN::String> parse_command(BAN::StringView command)
state = State::DoubleQuote; state = State::DoubleQuote;
else if (c == '$') else if (c == '$')
{ {
auto expansion = parse_dollar(command, i); auto expansion = parse_dollar(command_view, i);
if (!expansion.has_value()) if (!expansion.has_value())
{ {
fprintf(stderr, "bad substitution\n"); fprintf(stderr, "bad substitution\n");
return {}; return {};
} }
MUST(current.append(expansion.value())); MUST(current_arg.append(expansion.value()));
}
else if (c == '|')
{
if (!current_arg.empty())
MUST(command_args.push_back(current_arg));
current_arg.clear();
MUST(result.push_back(command_args));
command_args.clear();
} }
else if (!isspace(c)) else if (!isspace(c))
MUST(current.push_back(c)); MUST(current_arg.push_back(c));
else else
{ {
if (!current.empty()) if (!current_arg.empty())
{ {
MUST(result.push_back(current)); MUST(command_args.push_back(current_arg));
current.clear(); current_arg.clear();
} }
} }
break; break;
@ -200,43 +210,59 @@ BAN::Vector<BAN::String> parse_command(BAN::StringView command)
if (c == '\'') if (c == '\'')
state = State::Normal; state = State::Normal;
else else
MUST(current.push_back(c)); MUST(current_arg.push_back(c));
break; break;
case State::DoubleQuote: case State::DoubleQuote:
if (c == '"') if (c == '"')
state = State::Normal; state = State::Normal;
else if (c != '$') else if (c != '$')
MUST(current.push_back(c)); MUST(current_arg.push_back(c));
else else
{ {
auto expansion = parse_dollar(command, i); auto expansion = parse_dollar(command_view, i);
if (!expansion.has_value()) if (!expansion.has_value())
{ {
fprintf(stderr, "bad substitution\n"); fprintf(stderr, "bad substitution\n");
return {}; return {};
} }
MUST(current.append(expansion.value())); MUST(current_arg.append(expansion.value()));
} }
break; break;
} }
} }
// FIXME: handle state != State::Normal // FIXME: handle state != State::Normal
MUST(result.push_back(BAN::move(current))); MUST(command_args.push_back(BAN::move(current_arg)));
MUST(result.push_back(BAN::move(command_args)));
return result; return result;
} }
int execute_command(BAN::Vector<BAN::String>& args) int execute_command(BAN::Vector<BAN::String>& args, int fd_in, int fd_out);
BAN::Optional<int> execute_builtin(BAN::Vector<BAN::String>& args, int fd_in, int fd_out)
{ {
if (args.empty()) if (args.empty())
return 0; return 0;
FILE* fout = stdout;
bool should_close = false;
if (fd_out != STDOUT_FILENO)
{
int fd_dup = dup(fd_out);
if (fd_dup == -1)
ERROR_RETURN("dup", 1);
fout = fdopen(fd_dup, "w");
if (fout == nullptr)
ERROR_RETURN("fdopen", 1);
should_close = true;
}
BAN::ScopeGuard _([fout, should_close] { if (should_close) fclose(fout); });
if (args.front() == "clear"sv) if (args.front() == "clear"sv)
{ {
fprintf(stdout, "\e[H\e[J"); fprintf(fout, "\e[H\e[J");
fflush(stdout); fflush(fout);
return 0;
} }
else if (args.front() == "exit"sv) else if (args.front() == "exit"sv)
{ {
@ -265,7 +291,7 @@ int execute_command(BAN::Vector<BAN::String>& args)
{ {
char** current = environ; char** current = environ;
while (*current) while (*current)
printf("%s\n", *current++); fprintf(fout, "%s\n", *current++);
} }
else if (args.front() == "page-fault-test"sv) else if (args.front() == "page-fault-test"sv)
{ {
@ -277,7 +303,7 @@ int execute_command(BAN::Vector<BAN::String>& args)
pid_t pid = fork(); pid_t pid = fork();
if (pid == 0) if (pid == 0)
{ {
printf("child\n"); fprintf(fout, "child\n");
for (;;); for (;;);
} }
if (pid == -1) if (pid == -1)
@ -298,6 +324,7 @@ int execute_command(BAN::Vector<BAN::String>& args)
pid_t pid = fork(); pid_t pid = fork();
if (pid == 0) if (pid == 0)
{ {
dup2(fileno(fout), STDOUT_FILENO);
if (signal(SIGSEGV, [](int) { printf("SIGSEGV\n"); }) == SIG_ERR) if (signal(SIGSEGV, [](int) { printf("SIGSEGV\n"); }) == SIG_ERR)
{ {
perror("signal"); perror("signal");
@ -328,18 +355,18 @@ int execute_command(BAN::Vector<BAN::String>& args)
} }
else if (args.front() == "printf-test"sv) else if (args.front() == "printf-test"sv)
{ {
printf(" 0.0: %f\n", 0.0f); fprintf(fout, " 0.0: %f\n", 0.0f);
printf(" 123.0: %f\n", 123.0f); fprintf(fout, " 123.0: %f\n", 123.0f);
printf(" 0.123: %f\n", 0.123f); fprintf(fout, " 0.123: %f\n", 0.123f);
printf(" NAN: %f\n", NAN); fprintf(fout, " NAN: %f\n", NAN);
printf("+INF: %f\n", INFINITY); fprintf(fout, "+INF: %f\n", INFINITY);
printf("-INF: %f\n", -INFINITY); fprintf(fout, "-INF: %f\n", -INFINITY);
} }
else if (args.front() == "cd"sv) else if (args.front() == "cd"sv)
{ {
if (args.size() > 2) if (args.size() > 2)
{ {
printf("cd: too many arguments\n"); fprintf(fout, "cd: too many arguments\n");
return 1; return 1;
} }
@ -367,7 +394,7 @@ int execute_command(BAN::Vector<BAN::String>& args)
if (clock_gettime(CLOCK_MONOTONIC, &start) == -1) if (clock_gettime(CLOCK_MONOTONIC, &start) == -1)
ERROR_RETURN("clock_gettime", 1); ERROR_RETURN("clock_gettime", 1);
int ret = execute_command(args); int ret = execute_command(args, fd_in, fd_out);
if (clock_gettime(CLOCK_MONOTONIC, &end) == -1) if (clock_gettime(CLOCK_MONOTONIC, &end) == -1)
ERROR_RETURN("clock_gettime", 1); ERROR_RETURN("clock_gettime", 1);
@ -379,45 +406,154 @@ int execute_command(BAN::Vector<BAN::String>& args)
int secs = total_ns / 1'000'000'000; int secs = total_ns / 1'000'000'000;
int msecs = (total_ns % 1'000'000'000) / 1'000'000; int msecs = (total_ns % 1'000'000'000) / 1'000'000;
printf("took %d.%03d s\n", secs, msecs); fprintf(fout, "took %d.%03d s\n", secs, msecs);
return ret; return ret;
} }
else else
{ {
BAN::Vector<char*> cmd_args; return {};
MUST(cmd_args.reserve(args.size() + 1)); }
for (const auto& arg : args)
MUST(cmd_args.push_back((char*)arg.data()));
MUST(cmd_args.push_back(nullptr));
pid_t pid = fork(); return 0;
if (pid == 0) }
pid_t execute_command_no_wait(BAN::Vector<BAN::String>& args, int fd_in, int fd_out)
{
if (args.empty())
return 0;
BAN::Vector<char*> cmd_args;
MUST(cmd_args.reserve(args.size() + 1));
for (const auto& arg : args)
MUST(cmd_args.push_back((char*)arg.data()));
MUST(cmd_args.push_back(nullptr));
pid_t pid = fork();
if (pid == 0)
{
if (fd_in != STDIN_FILENO)
{ {
execv(cmd_args.front(), cmd_args.data()); if (dup2(fd_in, STDIN_FILENO) == -1)
perror("execv"); {
exit(1); perror("dup2");
exit(1);
}
close(fd_in);
}
if (fd_out != STDOUT_FILENO)
{
if (dup2(fd_out, STDOUT_FILENO) == -1)
{
perror("dup2");
exit(1);
}
close(fd_out);
} }
if (pid == -1)
ERROR_RETURN("fork", 1);
if (tcsetpgrp(0, pid) == -1) execv(cmd_args.front(), cmd_args.data());
ERROR_RETURN("tcsetpgrp", 1); perror("execv");
exit(1);
}
return pid;
}
int execute_command(BAN::Vector<BAN::String>& args, int fd_in, int fd_out)
{
pid_t pid = execute_command_no_wait(args, fd_in, fd_out);
if (pid == -1)
ERROR_RETURN("fork", 1);
if (tcsetpgrp(0, pid) == -1)
ERROR_RETURN("tcsetpgrp", 1);
int status;
if (waitpid(pid, &status, 0) == -1)
ERROR_RETURN("waitpid", 1);
if (tcsetpgrp(0, getpid()) == -1)
ERROR_RETURN("tcsetpgrp", 1);
if (WIFSIGNALED(status))
fprintf(stderr, "Terminated by signal %d\n", WTERMSIG(status));
return WEXITSTATUS(status);
}
int execute_piped_commands(BAN::Vector<BAN::Vector<BAN::String>>& commands)
{
if (commands.empty())
return 0;
if (commands.size() == 1)
{
auto& command = commands.front();
if (auto ret = execute_builtin(command, STDIN_FILENO, STDOUT_FILENO); ret.has_value())
return ret.value();
return execute_command(command, STDIN_FILENO, STDOUT_FILENO);
}
BAN::Vector<int> exit_codes(commands.size(), 0);
BAN::Vector<pid_t> processes(commands.size(), -1);
int next_stdin = STDIN_FILENO;
for (size_t i = 0; i < commands.size(); i++)
{
bool first = (i == 0);
bool last = (i == commands.size() - 1);
int pipefd[2] { -1, STDOUT_FILENO };
if (!last && pipe(pipefd) == -1)
{
if (i > 0)
close(next_stdin);
perror("pipe");
break;
}
auto builtin_ret = execute_builtin(commands[i], next_stdin, pipefd[1]);
if (builtin_ret.has_value())
exit_codes[i] = builtin_ret.value();
else
{
pid_t pid = execute_command_no_wait(commands[i], next_stdin, pipefd[1]);
processes[i] = pid;
if (first && tcsetpgrp(0, pid) == -1)
ERROR_RETURN("tcsetpgrp", 1);
}
if (next_stdin != STDIN_FILENO)
close(next_stdin);
if (pipefd[1] != STDOUT_FILENO)
close(pipefd[1]);
next_stdin = pipefd[0];
}
for (size_t i = 0; i < commands.size(); i++)
{
if (processes[i] == -1)
continue;
int status; int status;
if (waitpid(pid, &status, 0) == -1) if (waitpid(processes[i], &status, 0) == -1)
ERROR_RETURN("waitpid", 1); {
perror("waitpid");
if (tcsetpgrp(0, getpid()) == -1) exit_codes[i] = 69420;
ERROR_RETURN("tcsetpgrp", 1); continue;
}
if (WIFSIGNALED(status)) if (WIFSIGNALED(status))
fprintf(stderr, "Terminated by signal %d\n", WTERMSIG(status)); fprintf(stderr, "Terminated by signal %d\n", WTERMSIG(status));
return WEXITSTATUS(status); if (WEXITSTATUS(status))
exit_codes[i] = WEXITSTATUS(status);
} }
return 0; if (tcsetpgrp(0, getpid()) == -1)
ERROR_RETURN("tcsetpgrp", 1);
return exit_codes.back();
} }
int character_length(BAN::StringView prompt) int character_length(BAN::StringView prompt)
@ -544,8 +680,8 @@ int main(int argc, char** argv)
BAN::String command; BAN::String command;
MUST(command.append(argv[2])); MUST(command.append(argv[2]));
auto arguments = parse_command(command); auto commands = parse_command(command);
return execute_command(arguments); return execute_piped_commands(commands);
} }
printf("unknown argument '%s'\n", argv[1]); printf("unknown argument '%s'\n", argv[1]);
@ -657,8 +793,8 @@ int main(int argc, char** argv)
if (!buffers[index].empty()) if (!buffers[index].empty())
{ {
tcsetattr(0, TCSANOW, &old_termios); tcsetattr(0, TCSANOW, &old_termios);
auto parsed_arguments = parse_command(buffers[index]); auto commands = parse_command(buffers[index]);
last_return = execute_command(parsed_arguments); last_return = execute_piped_commands(commands);
tcsetattr(0, TCSANOW, &new_termios); tcsetattr(0, TCSANOW, &new_termios);
MUST(history.push_back(buffers[index])); MUST(history.push_back(buffers[index]));
buffers = history; buffers = history;