ladybird/Shell/main.cpp
Andreas Kling fc4022d173 Shell: Handle SIGWINCH to get a nice behavior when resizing.
When resizing the terminal, we now clear the entire current line and reset
the shell's LineEditor input state. This makes it look and feel kinda the
same as xterm.

Fixes #286.
2019-07-08 19:06:06 +02:00

620 lines
16 KiB
C++

#include "GlobalState.h"
#include "LineEditor.h"
#include "Parser.h"
#include <AK/FileSystemPath.h>
#include <AK/StringBuilder.h>
#include <LibCore/CDirIterator.h>
#include <LibCore/CElapsedTimer.h>
#include <LibCore/CFile.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <termios.h>
#include <unistd.h>
//#define SH_DEBUG
GlobalState g;
static LineEditor editor;
static void prompt()
{
if (g.uid == 0)
printf("# ");
else {
printf("\033]0;%s@%s:%s\007", g.username.characters(), g.hostname, g.cwd.characters());
printf("\033[31;1m%s\033[0m@\033[37;1m%s\033[0m:\033[32;1m%s\033[0m$> ", g.username.characters(), g.hostname, g.cwd.characters());
}
fflush(stdout);
}
static int sh_pwd(int, char**)
{
printf("%s\n", g.cwd.characters());
return 0;
}
static volatile bool g_got_signal = false;
void did_receive_signal(int signum)
{
printf("\nMy word, I've received a signal with number %d\n", signum);
g_got_signal = true;
}
static int sh_exit(int, char**)
{
printf("Good-bye!\n");
exit(0);
return 0;
}
static int sh_export(int argc, char** argv)
{
if (argc == 1) {
for (int i = 0; environ[i]; ++i)
puts(environ[i]);
return 0;
}
auto parts = String(argv[1]).split('=');
if (parts.size() != 2) {
fprintf(stderr, "usage: export variable=value\n");
return 1;
}
return setenv(parts[0].characters(), parts[1].characters(), 1);
}
static int sh_unset(int argc, char** argv)
{
if (argc != 2) {
fprintf(stderr, "usage: unset variable\n");
return 1;
}
unsetenv(argv[1]);
return 0;
}
static int sh_cd(int argc, char** argv)
{
char pathbuf[PATH_MAX];
if (argc == 1) {
strcpy(pathbuf, g.home.characters());
} else {
if (argv[1][0] == '/')
memcpy(pathbuf, argv[1], strlen(argv[1]) + 1);
else
sprintf(pathbuf, "%s/%s", g.cwd.characters(), argv[1]);
}
FileSystemPath canonical_path(pathbuf);
if (!canonical_path.is_valid()) {
printf("FileSystemPath failed to canonicalize '%s'\n", pathbuf);
return 1;
}
const char* path = canonical_path.string().characters();
struct stat st;
int rc = stat(path, &st);
if (rc < 0) {
printf("stat(%s) failed: %s\n", path, strerror(errno));
return 1;
}
if (!S_ISDIR(st.st_mode)) {
printf("Not a directory: %s\n", path);
return 1;
}
rc = chdir(path);
if (rc < 0) {
printf("chdir(%s) failed: %s\n", path, strerror(errno));
return 1;
}
g.cwd = canonical_path.string();
return 0;
}
static int sh_history(int, char**)
{
for (int i = 0; i < editor.history().size(); ++i) {
printf("%6d %s\n", i, editor.history()[i].characters());
}
return 0;
}
static int sh_umask(int argc, char** argv)
{
if (argc == 1) {
mode_t old_mask = umask(0);
printf("%#o\n", old_mask);
umask(old_mask);
return 0;
}
if (argc == 2) {
unsigned mask;
int matches = sscanf(argv[1], "%o", &mask);
if (matches == 1) {
umask(mask);
return 0;
}
}
printf("usage: umask <octal-mask>\n");
return 0;
}
static bool handle_builtin(int argc, char** argv, int& retval)
{
if (argc == 0)
return false;
if (!strcmp(argv[0], "cd")) {
retval = sh_cd(argc, argv);
return true;
}
if (!strcmp(argv[0], "pwd")) {
retval = sh_pwd(argc, argv);
return true;
}
if (!strcmp(argv[0], "exit")) {
retval = sh_exit(argc, argv);
return true;
}
if (!strcmp(argv[0], "export")) {
retval = sh_export(argc, argv);
return true;
}
if (!strcmp(argv[0], "unset")) {
retval = sh_unset(argc, argv);
return true;
}
if (!strcmp(argv[0], "history")) {
retval = sh_history(argc, argv);
return true;
}
if (!strcmp(argv[0], "umask")) {
retval = sh_umask(argc, argv);
return true;
}
return false;
}
class FileDescriptionCollector {
public:
FileDescriptionCollector() {}
~FileDescriptionCollector() { collect(); }
void collect()
{
for (auto fd : m_fds)
close(fd);
m_fds.clear();
}
void add(int fd) { m_fds.append(fd); }
private:
Vector<int, 32> m_fds;
};
struct CommandTimer {
CommandTimer()
{
timer.start();
}
~CommandTimer()
{
dbgprintf("sh: command finished in %d ms\n", timer.elapsed());
}
CElapsedTimer timer;
};
static bool is_glob(const StringView& s)
{
for (int i = 0; i < s.length(); i++) {
char c = s.characters_without_null_termination()[i];
if (c == '*' || c == '?')
return true;
}
return false;
}
static Vector<StringView> split_path(const StringView &path)
{
Vector<StringView> parts;
ssize_t substart = 0;
for (ssize_t i = 0; i < path.length(); i++) {
char ch = path.characters_without_null_termination()[i];
if (ch != '/')
continue;
ssize_t sublen = i - substart;
if (sublen != 0)
parts.append(path.substring_view(substart, sublen));
parts.append(path.substring_view(i, 1));
substart = i + 1;
}
ssize_t taillen = path.length() - substart;
if (taillen != 0)
parts.append(path.substring_view(substart, taillen));
return parts;
}
static Vector<String> expand_globs(const StringView& path, const StringView& base)
{
auto parts = split_path(path);
StringBuilder builder;
builder.append(base);
Vector<String> res;
for (int i = 0; i < parts.size(); ++i) {
auto& part = parts[i];
if (!is_glob(part)) {
builder.append(part);
continue;
}
// Found a glob.
String new_base = builder.to_string();
StringView new_base_v = new_base;
if (new_base_v.is_empty())
new_base_v = ".";
CDirIterator di(new_base_v, CDirIterator::NoFlags);
if (di.has_error()) {
return res;
}
while (di.has_next()) {
String name = di.next_path();
// Dotfiles have to be explicitly requested
if (name[0] == '.' && part[0] != '.')
continue;
// And even if they are, skip . and ..
if (name == "." || name == "..")
continue;
if (name.matches(part, String::CaseSensitivity::CaseSensitive)) {
StringBuilder nested_base;
nested_base.append(new_base);
nested_base.append(name);
StringView remaining_path = path.substring_view_starting_after_substring(part);
Vector<String> nested_res = expand_globs(remaining_path, nested_base.to_string());
for (auto& s : nested_res)
res.append(s);
}
}
return res;
}
// Found no globs.
String new_path = builder.to_string();
if (access(new_path.characters(), F_OK) == 0)
res.append(new_path);
return res;
}
static Vector<String> process_arguments(const Vector<String>& args)
{
Vector<String> argv_string;
for (auto& arg : args) {
auto expanded = expand_globs(arg, "");
if (expanded.is_empty())
argv_string.append(arg);
else
for (auto& path : expand_globs(arg, ""))
argv_string.append(path);
}
return argv_string;
}
static int run_command(const String& cmd)
{
if (cmd.is_empty())
return 0;
auto subcommands = Parser(cmd).parse();
#ifdef SH_DEBUG
for (int i = 0; i < subcommands.size(); ++i) {
for (int j = 0; j < i; ++j)
dbgprintf(" ");
for (auto& arg : subcommands[i].args) {
dbgprintf("<%s> ", arg.characters());
}
dbgprintf("\n");
for (auto& redirecton : subcommands[i].redirections) {
for (int j = 0; j < i; ++j)
dbgprintf(" ");
dbgprintf(" ");
switch (redirecton.type) {
case Redirection::Pipe:
dbgprintf("Pipe\n");
break;
case Redirection::FileRead:
dbgprintf("fd:%d = FileRead: %s\n", redirecton.fd, redirecton.path.characters());
break;
case Redirection::FileWrite:
dbgprintf("fd:%d = FileWrite: %s\n", redirecton.fd, redirecton.path.characters());
break;
case Redirection::FileWriteAppend:
dbgprintf("fd:%d = FileWriteAppend: %s\n", redirecton.fd, redirecton.path.characters());
break;
default:
break;
}
}
}
#endif
if (subcommands.is_empty())
return 0;
FileDescriptionCollector fds;
for (int i = 0; i < subcommands.size(); ++i) {
auto& subcommand = subcommands[i];
for (auto& redirection : subcommand.redirections) {
switch (redirection.type) {
case Redirection::Pipe: {
int pipefd[2];
int rc = pipe(pipefd);
if (rc < 0) {
perror("pipe");
return 1;
}
subcommand.rewirings.append({ STDOUT_FILENO, pipefd[1] });
auto& next_command = subcommands[i + 1];
next_command.rewirings.append({ STDIN_FILENO, pipefd[0] });
fds.add(pipefd[0]);
fds.add(pipefd[1]);
break;
}
case Redirection::FileWriteAppend: {
int fd = open(redirection.path.characters(), O_WRONLY | O_CREAT | O_APPEND, 0666);
if (fd < 0) {
perror("open");
return 1;
}
subcommand.rewirings.append({ redirection.fd, fd });
fds.add(fd);
break;
}
case Redirection::FileWrite: {
int fd = open(redirection.path.characters(), O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (fd < 0) {
perror("open");
return 1;
}
subcommand.rewirings.append({ redirection.fd, fd });
fds.add(fd);
break;
}
case Redirection::FileRead: {
int fd = open(redirection.path.characters(), O_RDONLY);
if (fd < 0) {
perror("open");
return 1;
}
subcommand.rewirings.append({ redirection.fd, fd });
fds.add(fd);
break;
}
}
}
}
struct termios trm;
tcgetattr(0, &trm);
struct SpawnedProcess {
String name;
pid_t pid;
};
Vector<SpawnedProcess> children;
CommandTimer timer;
for (int i = 0; i < subcommands.size(); ++i) {
auto& subcommand = subcommands[i];
Vector<String> argv_string = process_arguments(subcommand.args);
Vector<const char*> argv;
argv.ensure_capacity(argv_string.size());
for (const auto& s : argv_string) {
argv.append(s.characters());
}
argv.append(nullptr);
#ifdef SH_DEBUG
for (auto& arg : argv) {
dbgprintf("<%s> ", arg);
}
dbgprintf("\n");
#endif
int retval = 0;
if (handle_builtin(argv.size() - 1, const_cast<char**>(argv.data()), retval))
return retval;
pid_t child = fork();
if (!child) {
setpgid(0, 0);
tcsetpgrp(0, getpid());
for (auto& rewiring : subcommand.rewirings) {
#ifdef SH_DEBUG
dbgprintf("in %s<%d>, dup2(%d, %d)\n", argv[0], getpid(), redirection.rewire_fd, redirection.fd);
#endif
int rc = dup2(rewiring.rewire_fd, rewiring.fd);
if (rc < 0) {
perror("dup2");
return 1;
}
}
fds.collect();
int rc = execvp(argv[0], const_cast<char* const*>(argv.data()));
if (rc < 0) {
fprintf(stderr, "execvp(%s): %s\n", argv[0], strerror(errno));
exit(1);
}
ASSERT_NOT_REACHED();
}
children.append({ argv[0], child });
}
#ifdef SH_DEBUG
dbgprintf("Closing fds in shell process:\n");
#endif
fds.collect();
#ifdef SH_DEBUG
dbgprintf("Now we gotta wait on children:\n");
for (auto& child : children)
dbgprintf(" %d\n", child);
#endif
int wstatus = 0;
int return_value = 0;
for (int i = 0; i < children.size(); ++i) {
auto& child = children[i];
do {
int rc = waitpid(child.pid, &wstatus, 0);
if (rc < 0 && errno != EINTR) {
if (errno != ECHILD)
perror("waitpid");
break;
}
if (WIFEXITED(wstatus)) {
if (WEXITSTATUS(wstatus) != 0)
printf("Shell: %s(%d) exited with status %d\n", child.name.characters(), child.pid, WEXITSTATUS(wstatus));
if (i == 0)
return_value = WEXITSTATUS(wstatus);
} else {
if (WIFSIGNALED(wstatus)) {
printf("Shell: %s(%d) exited due to signal '%s'\n", child.name.characters(), child.pid, strsignal(WTERMSIG(wstatus)));
} else {
printf("Shell: %s(%d) exited abnormally\n", child.name.characters(), child.pid);
}
}
} while (errno == EINTR);
}
// FIXME: Should I really have to tcsetpgrp() after my child has exited?
// Is the terminal controlling pgrp really still the PGID of the dead process?
tcsetpgrp(0, getpid());
tcsetattr(0, TCSANOW, &trm);
return return_value;
}
CFile get_history_file()
{
StringBuilder sb;
sb.append(g.home);
sb.append("/.history");
CFile f(sb.to_string());
if (!f.open(CIODevice::ReadWrite)) {
fprintf(stderr, "Error opening file '%s': '%s'\n", f.filename().characters(), f.error_string());
exit(1);
}
return f;
}
void load_history()
{
CFile history_file = get_history_file();
while (history_file.can_read_line()) {
const auto&b = history_file.read_line(1024);
// skip the newline and terminating bytes
editor.add_to_history(String(reinterpret_cast<const char*>(b.pointer()), b.size() - 2));
}
}
void save_history()
{
CFile history_file = get_history_file();
for (const auto& line : editor.history()) {
history_file.write(line);
history_file.write("\n");
}
}
int main(int argc, char** argv)
{
g.uid = getuid();
g.sid = setsid();
tcsetpgrp(0, getpgrp());
tcgetattr(0, &g.termios);
signal(SIGINT, [](int) {
g.was_interrupted = true;
});
signal(SIGHUP, [](int) {
save_history();
});
signal(SIGWINCH, [](int) {
g.was_resized = true;
});
int rc = gethostname(g.hostname, sizeof(g.hostname));
if (rc < 0)
perror("gethostname");
rc = ttyname_r(0, g.ttyname, sizeof(g.ttyname));
if (rc < 0)
perror("ttyname_r");
{
auto* pw = getpwuid(getuid());
if (pw) {
g.username = pw->pw_name;
g.home = pw->pw_dir;
setenv("HOME", pw->pw_dir, 1);
}
endpwent();
}
if (argc > 2 && !strcmp(argv[1], "-c")) {
dbgprintf("sh -c '%s'\n", argv[2]);
run_command(argv[2]);
return 0;
}
{
auto* cwd = getcwd(nullptr, 0);
g.cwd = cwd;
free(cwd);
}
load_history();
atexit(save_history);
for (;;) {
prompt();
auto line = editor.get_line();
if (line.is_empty())
continue;
run_command(line);
editor.add_to_history(line);
}
return 0;
}