1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/*
* Copyright (c) 2020, Sahan Fernando <sahan.h.fernando@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Assertions.h>
#include <AK/DeprecatedString.h>
#include <AK/StringBuilder.h>
#include <AK/Time.h>
#include <AK/Vector.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/DeprecatedFile.h>
#include <LibCore/FileWatcher.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <errno.h>
#include <spawn.h>
#include <stdio.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
static int opt_interval = 2;
static bool flag_noheader = false;
static bool flag_beep_on_fail = false;
static int volatile exit_code = 0;
static volatile pid_t child_pid = -1;
static DeprecatedString build_header_string(Vector<char const*> const& command, struct timeval const& interval)
{
StringBuilder builder;
builder.appendff("Every {}.{}s: \x1b[1m", interval.tv_sec, interval.tv_usec / 100000);
builder.join(' ', command);
builder.append("\x1b[0m"sv);
return builder.to_deprecated_string();
}
static DeprecatedString build_header_string(Vector<char const*> const& command, Vector<DeprecatedString> const& filenames)
{
StringBuilder builder;
builder.appendff("Every time any of {} changes: \x1b[1m", filenames);
builder.join(' ', command);
builder.append("\x1b[0m"sv);
return builder.to_deprecated_string();
}
static struct timeval get_current_time()
{
struct timespec ts;
struct timeval tv;
clock_gettime(CLOCK_MONOTONIC_COARSE, &ts);
timespec_to_timeval(ts, tv);
return tv;
}
static int64_t usecs_from(struct timeval const& start, struct timeval const& end)
{
struct timeval diff;
timeval_sub(end, start, diff);
return 1000000 * diff.tv_sec + diff.tv_usec;
}
static void handle_signal(int signal)
{
if (child_pid > 0) {
if (kill(child_pid, signal) < 0) {
perror("kill");
}
int status;
if (waitpid(child_pid, &status, 0) < 0) {
perror("waitpid");
} else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
exit_code = 1;
}
}
exit(exit_code);
}
static int run_command(Vector<char const*> const& command)
{
VERIFY(command[command.size() - 1] == nullptr);
if ((errno = posix_spawnp(const_cast<pid_t*>(&child_pid), command[0], nullptr, nullptr, const_cast<char**>(command.data()), environ))) {
exit_code = 1;
perror("posix_spawn");
return errno;
}
// Wait for the child to terminate, then return its exit code.
int status;
pid_t exited_pid;
do {
exited_pid = waitpid(child_pid, &status, 0);
} while (exited_pid < 0 && errno == EINTR);
VERIFY(exited_pid == child_pid);
child_pid = -1;
if (exited_pid < 0) {
perror("waitpid");
return 1;
}
if (WIFEXITED(status)) {
return WEXITSTATUS(status);
} else {
return 1;
}
}
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
TRY(Core::System::signal(SIGINT, handle_signal));
TRY(Core::System::pledge("stdio proc exec rpath"));
Vector<DeprecatedString> files_to_watch;
Vector<char const*> command;
Core::ArgsParser args_parser;
args_parser.set_stop_on_first_non_option(true);
args_parser.set_general_help("Execute a command repeatedly, and watch its output over time.");
args_parser.add_option(opt_interval, "Amount of time between updates", "interval", 'n', "seconds");
args_parser.add_option(flag_noheader, "Turn off the header describing the command and interval", "no-title", 't');
args_parser.add_option(flag_beep_on_fail, "Beep if the command has a non-zero exit code", "beep", 'b');
Core::ArgsParser::Option file_arg {
.argument_mode = Core::ArgsParser::OptionArgumentMode::Required,
.help_string = "Run command whenever this file changes. Can be used multiple times.",
.long_name = "file",
.short_name = 'f',
.value_name = "file",
.accept_value = [&files_to_watch](auto filename) {
files_to_watch.append(filename);
return true;
}
};
args_parser.add_option(move(file_arg));
args_parser.add_positional_argument(command, "Command to run", "command");
args_parser.parse(arguments);
command.append(nullptr);
DeprecatedString header;
auto watch_callback = [&] {
// Clear the screen, then reset the cursor position to the top left.
warn("\033[H\033[2J");
// Print the header.
if (!flag_noheader) {
warnln("{}", header);
warnln();
} else {
fflush(stderr);
}
if (run_command(command) != 0) {
exit_code = 1;
if (flag_beep_on_fail) {
warnln("\a");
fflush(stderr);
}
}
};
if (!files_to_watch.is_empty()) {
header = build_header_string(command, files_to_watch);
auto file_watcher = Core::BlockingFileWatcher();
for (auto const& file : files_to_watch) {
if (!Core::DeprecatedFile::exists(file)) {
warnln("Cannot watch '{}', it does not exist.", file);
return 1;
}
if (!file_watcher.is_watching(file)) {
auto could_add_to_watch = TRY(file_watcher.add_watch(file, Core::FileWatcherEvent::Type::MetadataModified));
if (!could_add_to_watch) {
warnln("Could not add '{}' to watch list.", file);
return 1;
}
}
}
watch_callback();
while (true) {
auto maybe_event = file_watcher.wait_for_event();
if (maybe_event.has_value()) {
watch_callback();
}
}
} else {
TRY(Core::System::pledge("stdio proc exec"));
struct timeval interval;
if (opt_interval <= 0) {
interval = { 0, 100000 };
} else {
interval = { opt_interval, 0 };
}
auto now = get_current_time();
auto next_run_time = now;
header = build_header_string(command, interval);
while (true) {
int usecs_to_sleep = usecs_from(now, next_run_time);
while (usecs_to_sleep > 0) {
usleep(usecs_to_sleep);
now = get_current_time();
usecs_to_sleep = usecs_from(now, next_run_time);
}
watch_callback();
now = get_current_time();
timeval_add(next_run_time, interval, next_run_time);
if (usecs_from(now, next_run_time) < 0) {
// The next execution is overdue, so we set next_run_time to now to prevent drift.
next_run_time = now;
}
}
}
}
|
