ladybird/Userland/find.cpp
Ben Wiederhake 0248ddc427 Userland: Mark compilation-unit-only functions as static
This enables a nice warning in case a function becomes dead code.
2020-08-12 20:40:59 +02:00

469 lines
13 KiB
C++

/*
* Copyright (c) 2020, Sergey Bugaev <bugaevc@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 <AK/NonnullOwnPtr.h>
#include <AK/OwnPtr.h>
#include <AK/Vector.h>
#include <LibCore/DirIterator.h>
#include <getopt.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
bool g_follow_symlinks = false;
bool g_there_was_an_error = false;
bool g_have_seen_action_command = false;
[[noreturn]] static void fatal_error(const char* format, ...)
{
fputs("\033[31m", stderr);
va_list ap;
va_start(ap, format);
vfprintf(stderr, format, ap);
va_end(ap);
fputs("\033[0m\n", stderr);
exit(1);
}
class Command {
public:
virtual ~Command() { }
virtual bool evaluate(const char* file_path) const = 0;
};
class StatCommand : public Command {
public:
virtual bool evaluate(const struct stat&) const = 0;
private:
virtual bool evaluate(const char* file_path) const override
{
struct stat stat;
auto stat_func = g_follow_symlinks ? ::stat : ::lstat;
int rc = stat_func(file_path, &stat);
if (rc < 0) {
perror(file_path);
g_there_was_an_error = true;
return false;
}
return evaluate(stat);
}
};
class TypeCommand final : public StatCommand {
public:
TypeCommand(const char* arg)
{
StringView type = arg;
if (type.length() != 1 || !StringView("bcdlpfs").contains(type[0]))
fatal_error("Invalid mode: \033[1m%s", arg);
m_type = type[0];
}
private:
virtual bool evaluate(const struct stat& stat) const override
{
auto type = stat.st_mode;
switch (m_type) {
case 'b':
return S_ISBLK(type);
case 'c':
return S_ISCHR(type);
case 'd':
return S_ISDIR(type);
case 'l':
return S_ISLNK(type);
case 'p':
return S_ISFIFO(type);
case 'f':
return S_ISREG(type);
case 's':
return S_ISSOCK(type);
default:
// We've verified this is a correct character before.
ASSERT_NOT_REACHED();
}
}
char m_type { 0 };
};
class LinksCommand final : public StatCommand {
public:
LinksCommand(const char* arg)
{
auto number = StringView(arg).to_uint();
if (!number.has_value())
fatal_error("Invalid number: \033[1m%s", arg);
m_links = number.value();
}
private:
virtual bool evaluate(const struct stat& stat) const override
{
return stat.st_nlink == m_links;
}
nlink_t m_links { 0 };
};
class UserCommand final : public StatCommand {
public:
UserCommand(const char* arg)
{
if (struct passwd* passwd = getpwnam(arg)) {
m_uid = passwd->pw_uid;
} else {
// Attempt to parse it as decimal UID.
auto number = StringView(arg).to_uint();
if (!number.has_value())
fatal_error("Invalid user: \033[1m%s", arg);
m_uid = number.value();
}
}
private:
virtual bool evaluate(const struct stat& stat) const override
{
return stat.st_uid == m_uid;
}
uid_t m_uid { 0 };
};
class GroupCommand final : public StatCommand {
public:
GroupCommand(const char* arg)
{
if (struct group* gr = getgrnam(arg)) {
m_gid = gr->gr_gid;
} else {
// Attempt to parse it as decimal GID.
auto number = StringView(arg).to_int();
if (!number.has_value())
fatal_error("Invalid group: \033[1m%s", arg);
m_gid = number.value();
}
}
private:
virtual bool evaluate(const struct stat& stat) const override
{
return stat.st_gid == m_gid;
}
gid_t m_gid { 0 };
};
class SizeCommand final : public StatCommand {
public:
SizeCommand(const char* arg)
{
StringView view = arg;
if (view.ends_with('c')) {
m_is_bytes = true;
view = view.substring_view(0, view.length() - 1);
}
auto number = view.to_uint();
if (!number.has_value())
fatal_error("Invalid size: \033[1m%s", arg);
m_size = number.value();
}
private:
virtual bool evaluate(const struct stat& stat) const override
{
if (m_is_bytes)
return stat.st_size == m_size;
auto size_divided_by_512_rounded_up = (stat.st_size + 511) / 512;
return size_divided_by_512_rounded_up == m_size;
}
off_t m_size { 0 };
bool m_is_bytes { false };
};
class PrintCommand final : public Command {
public:
PrintCommand(char terminator = '\n')
: m_terminator(terminator)
{
}
private:
virtual bool evaluate(const char* file_path) const override
{
printf("%s%c", file_path, m_terminator);
return true;
}
char m_terminator { '\n' };
};
class ExecCommand final : public Command {
public:
ExecCommand(Vector<char*>&& argv)
: m_argv(move(argv))
{
}
private:
virtual bool evaluate(const char* file_path) const override
{
pid_t pid = fork();
if (pid < 0) {
perror("fork");
g_there_was_an_error = true;
return false;
} else if (pid == 0) {
// Replace any occurrences of "{}" with the path. Since we're in the
// child and going to exec real soon, let's just const_cast away the
// constness.
auto argv = const_cast<Vector<char*>&>(m_argv);
for (auto& arg : argv) {
if (StringView(arg) == "{}")
arg = const_cast<char*>(file_path);
}
argv.append(nullptr);
execvp(m_argv[0], argv.data());
perror("execvp");
exit(1);
} else {
int status;
int rc = waitpid(pid, &status, 0);
if (rc < 0) {
perror("waitpid");
g_there_was_an_error = true;
return false;
}
return WIFEXITED(status) && WEXITSTATUS(status) == 0;
}
}
Vector<char*> m_argv;
};
class AndCommand final : public Command {
public:
AndCommand(NonnullOwnPtr<Command>&& lhs, NonnullOwnPtr<Command>&& rhs)
: m_lhs(move(lhs))
, m_rhs(move(rhs))
{
}
private:
virtual bool evaluate(const char* file_path) const override
{
return m_lhs->evaluate(file_path) && m_rhs->evaluate(file_path);
}
NonnullOwnPtr<Command> m_lhs;
NonnullOwnPtr<Command> m_rhs;
};
class OrCommand final : public Command {
public:
OrCommand(NonnullOwnPtr<Command>&& lhs, NonnullOwnPtr<Command>&& rhs)
: m_lhs(move(lhs))
, m_rhs(move(rhs))
{
}
private:
virtual bool evaluate(const char* file_path) const override
{
return m_lhs->evaluate(file_path) || m_rhs->evaluate(file_path);
}
NonnullOwnPtr<Command> m_lhs;
NonnullOwnPtr<Command> m_rhs;
};
static OwnPtr<Command> parse_complex_command(char* argv[]);
// Parse a simple command starting at optind; leave optind at its the last
// argument. Return nullptr if we reach the end of arguments.
static OwnPtr<Command> parse_simple_command(char* argv[])
{
StringView arg = argv[optind];
if (arg.is_null()) {
return nullptr;
} else if (arg == "(") {
optind++;
auto command = parse_complex_command(argv);
if (command && argv[optind] && StringView(argv[++optind]) == ")")
return command;
fatal_error("Unmatched \033[1m(");
} else if (arg == "-type") {
return make<TypeCommand>(argv[++optind]);
} else if (arg == "-links") {
return make<LinksCommand>(argv[++optind]);
} else if (arg == "-user") {
return make<UserCommand>(argv[++optind]);
} else if (arg == "-group") {
return make<GroupCommand>(argv[++optind]);
} else if (arg == "-size") {
return make<SizeCommand>(argv[++optind]);
} else if (arg == "-print") {
g_have_seen_action_command = true;
return make<PrintCommand>();
} else if (arg == "-print0") {
g_have_seen_action_command = true;
return make<PrintCommand>(0);
} else if (arg == "-exec") {
g_have_seen_action_command = true;
Vector<char*> command_argv;
while (argv[++optind] && StringView(argv[optind]) != ";")
command_argv.append(argv[optind]);
return make<ExecCommand>(move(command_argv));
} else {
fatal_error("Unsupported command \033[1m%s", argv[optind]);
}
}
static OwnPtr<Command> parse_complex_command(char* argv[])
{
auto command = parse_simple_command(argv);
while (command && argv[optind] && argv[optind + 1]) {
StringView arg = argv[++optind];
enum { And,
Or } binary_operation
= And;
if (arg == "-a") {
optind++;
binary_operation = And;
} else if (arg == "-o") {
optind++;
binary_operation = Or;
} else if (arg == ")") {
// Ooops, looked too far.
optind--;
return command;
} else {
// Juxtaposition is an And too, and there's nothing to skip.
binary_operation = And;
}
auto rhs = parse_complex_command(argv);
if (!rhs)
fatal_error("Missing right-hand side");
if (binary_operation == And)
command = make<AndCommand>(command.release_nonnull(), rhs.release_nonnull());
else
command = make<OrCommand>(command.release_nonnull(), rhs.release_nonnull());
}
return command;
}
static NonnullOwnPtr<Command> parse_all_commands(char* argv[])
{
auto command = parse_complex_command(argv);
if (g_have_seen_action_command) {
ASSERT(command);
return command.release_nonnull();
}
if (!command) {
return make<PrintCommand>();
}
return make<AndCommand>(command.release_nonnull(), make<PrintCommand>());
}
static const char* parse_options(int argc, char* argv[])
{
// Sadly, we can't use Core::ArgsParser, because find accepts arguments in
// an extremely unusual format. We're going to try to use getopt(), though.
opterr = 0;
while (true) {
int opt = getopt(argc, argv, "+L");
switch (opt) {
case -1: {
// No more options.
StringView arg = argv[optind];
if (!arg.is_null() && !arg.starts_with('-')) {
// It's our root path!
return argv[optind++];
} else {
// It's a part of the script, and our root path is the current
// directory by default.
return ".";
}
}
case '?':
// Some error. Most likely, it's getopt() getting confused about
// what it thought was an option, but is actually a command. Return
// the default path, and hope the command parsing logic deals with
// this.
return ".";
case 'L':
g_follow_symlinks = true;
break;
default:
ASSERT_NOT_REACHED();
}
}
}
static void walk_tree(const char* root_path, Command& command)
{
command.evaluate(root_path);
Core::DirIterator dir_iterator(root_path, Core::DirIterator::SkipParentAndBaseDir);
if (dir_iterator.has_error() && dir_iterator.error() == ENOTDIR)
return;
while (dir_iterator.has_next())
walk_tree(dir_iterator.next_full_path().characters(), command);
if (dir_iterator.has_error()) {
fprintf(stderr, "%s: %s\n", root_path, dir_iterator.error_string());
g_there_was_an_error = true;
}
}
int main(int argc, char* argv[])
{
auto root_path = parse_options(argc, argv);
auto command = parse_all_commands(argv);
walk_tree(root_path, *command);
return g_there_was_an_error ? 1 : 0;
}