ladybird/Userland/Utilities/pgrep.cpp
Tim Ledbetter b863332415 pgrep: Add -O option to filter processes by age
This option allows the user to specify a number of seconds. Only
processes older than the given number of seconds are selected.
2023-06-10 07:13:25 +02:00

155 lines
6.0 KiB
C++

/*
* Copyright (c) 2021, Aziz Berkay Yesilyurt <abyesilyurt@gmail.com>
* Copyright (c) 2023, Tim Ledbetter <timledbetter@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/QuickSort.h>
#include <AK/Vector.h>
#include <LibCore/Account.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/ProcessStatisticsReader.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <LibRegex/Regex.h>
ErrorOr<int> serenity_main(Main::Arguments args)
{
TRY(Core::System::pledge("stdio rpath"));
TRY(Core::System::unveil("/sys/kernel/processes", "r"));
TRY(Core::System::unveil("/etc/group", "r"));
TRY(Core::System::unveil("/etc/passwd", "r"));
TRY(Core::System::unveil(nullptr, nullptr));
bool display_number_of_matches = false;
auto pid_delimiter = "\n"sv;
bool case_insensitive = false;
bool list_process_name = false;
bool invert_match = false;
bool exact_match = false;
bool newest_only = false;
bool oldest_only = false;
Optional<UnixDateTime> display_if_older_than;
HashTable<uid_t> uids_to_filter_by;
StringView pattern;
Core::ArgsParser args_parser;
args_parser.add_option(display_number_of_matches, "Suppress normal output and print the number of matching processes", "count", 'c');
args_parser.add_option(pid_delimiter, "Set the string used to delimit multiple pids", "delimiter", 'd', nullptr);
args_parser.add_option(case_insensitive, "Make matches case-insensitive", "ignore-case", 'i');
args_parser.add_option(newest_only, "Select the most recently created process only", "newest", 'n');
args_parser.add_option(oldest_only, "Select the least recently created process only", "oldest", 'o');
args_parser.add_option(list_process_name, "List the process name in addition to its pid", "list-name", 'l');
args_parser.add_option(Core::ArgsParser::Option {
.argument_mode = Core::ArgsParser::OptionArgumentMode::Required,
.help_string = "Select only processes older than the specified number of seconds",
.long_name = "older",
.short_name = 'O',
.value_name = "seconds",
.accept_value = [&display_if_older_than](StringView seconds_string) {
auto number = seconds_string.to_uint<u64>();
if (number.has_value() && number.value() <= NumericLimits<i64>::max()) {
auto now_time = UnixDateTime::now();
display_if_older_than = now_time - Duration::from_seconds(static_cast<i64>(number.value()));
}
return display_if_older_than.has_value();
},
});
args_parser.add_option(Core::ArgsParser::Option {
.argument_mode = Core::ArgsParser::OptionArgumentMode::Required,
.help_string = "Select only processes whose UID is in the given comma-separated list. Login name or numerical user ID may be used",
.long_name = "uid",
.short_name = 'U',
.value_name = "uid-list",
.accept_value = [&uids_to_filter_by](StringView comma_separated_users) {
for (auto user_string : comma_separated_users.split_view(',')) {
auto maybe_uid = user_string.to_uint<uid_t>();
if (maybe_uid.has_value()) {
uids_to_filter_by.set(maybe_uid.value());
} else {
auto maybe_account = Core::Account::from_name(user_string, Core::Account::Read::PasswdOnly);
if (maybe_account.is_error()) {
warnln("Could not find user '{}': {}", user_string, maybe_account.error());
return false;
}
uids_to_filter_by.set(maybe_account.release_value().uid());
}
}
return true;
},
});
args_parser.add_option(invert_match, "Select non-matching lines", "invert-match", 'v');
args_parser.add_option(exact_match, "Select only processes whose names match the given pattern exactly", "exact", 'x');
args_parser.add_positional_argument(pattern, "Process name to search for", "process-name");
args_parser.parse(args);
if (newest_only && oldest_only) {
warnln("The -n and -o options are mutually exclusive");
args_parser.print_usage(stderr, args.strings[0]);
return 1;
}
PosixOptions options {};
if (case_insensitive)
options |= PosixFlags::Insensitive;
StringBuilder exact_pattern_builder;
if (exact_match) {
exact_pattern_builder.appendff("^({})$", pattern);
pattern = exact_pattern_builder.string_view();
}
Regex<PosixExtended> re(pattern, options);
if (re.parser_result.error != regex::Error::NoError) {
return 1;
}
auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
Vector<Core::ProcessStatistics> matches;
for (auto const& it : all_processes.processes) {
auto result = re.match(it.name, PosixFlags::Global);
if (result.success ^ invert_match) {
if (!uids_to_filter_by.is_empty() && !uids_to_filter_by.contains(it.uid))
continue;
if (display_if_older_than.has_value() && it.creation_time >= display_if_older_than.value())
continue;
matches.append(it);
}
}
if (display_number_of_matches) {
outln("{}", matches.size());
} else if (!matches.is_empty()) {
quick_sort(matches, [](auto const& a, auto const& b) { return a.creation_time < b.creation_time; });
if (newest_only)
matches = { matches.last() };
else if (oldest_only)
matches = { matches.first() };
auto displayed_at_least_one = false;
for (auto& match : matches) {
if (displayed_at_least_one)
out("{}"sv, pid_delimiter);
out("{}"sv, match.pid);
if (list_process_name)
out(" {}"sv, match.name);
displayed_at_least_one = true;
}
if (displayed_at_least_one)
outln();
}
return matches.is_empty() ? 1 : 0;
}