ladybird/Userland/Utilities/paste.cpp
Sergey Bugaev d8faafef14 Userland: Implement paste --watch mode
You can now watch the clipboard for changes and run a command each time
the clipboard contents change like this:

$ paste --watch some command here

The command will be spawned each time the clipboard contents change. It
can read the clipboard contents from its stdin, and CLIPBOARD_STATE
environment variable will be set to "data" if there is data to be read,
or to "nil"/"clear" if the clipboard has been cleared.
2021-05-10 19:09:53 +01:00

109 lines
3.0 KiB
C++

/*
* Copyright (c) 2019-2021, Sergey Bugaev <bugaevc@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <AK/String.h>
#include <LibCore/ArgsParser.h>
#include <LibGUI/Application.h>
#include <LibGUI/Clipboard.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
static void spawn_command(const Vector<const char*>& command, const ByteBuffer& data, const char* state)
{
int pipefd[2];
if (pipe(pipefd) < 0) {
perror("pipe");
return;
}
pid_t pid = fork();
if (pid < 0) {
perror("fork");
return;
} else if (pid == 0) {
// We're the child.
dup2(pipefd[0], 0);
close(pipefd[0]);
close(pipefd[1]);
setenv("CLIPBOARD_STATE", state, true);
execvp(command[0], const_cast<char**>(command.data()));
perror("exec");
exit(1);
}
// We're the parent.
close(pipefd[0]);
FILE* f = fdopen(pipefd[1], "w");
fwrite(data.data(), data.size(), 1, f);
if (ferror(f))
warnln("failed to write data to the pipe: {}", strerror(ferror(f)));
fclose(f);
if (wait(nullptr) < 0)
perror("wait");
}
int main(int argc, char* argv[])
{
bool print_type = false;
bool no_newline = false;
bool watch = false;
Vector<const char*> watch_command;
Core::ArgsParser args_parser;
args_parser.set_general_help("Paste from the clipboard to stdout.");
args_parser.add_option(print_type, "Display the copied type", "print-type", 0);
args_parser.add_option(no_newline, "Do not append a newline", "no-newline", 'n');
args_parser.add_option(watch, "Run a command when clipboard data changes", "watch", 'w');
args_parser.add_positional_argument(watch_command, "Command to run in watch mode", "command", Core::ArgsParser::Required::No);
args_parser.parse(argc, argv);
auto app = GUI::Application::construct(argc, argv);
auto& clipboard = GUI::Clipboard::the();
if (watch) {
watch_command.append(nullptr);
clipboard.on_change = [&](const String&) {
// Technically there's a race here...
auto data_and_type = clipboard.data_and_type();
if (data_and_type.mime_type.is_null()) {
spawn_command(watch_command, {}, "clear");
} else {
spawn_command(watch_command, data_and_type.data, "data");
}
};
// Trigger it the first time immediately.
clipboard.on_change({});
return app->exec();
}
auto data_and_type = clipboard.data_and_type();
if (data_and_type.mime_type.is_null()) {
warnln("Nothing copied");
return 1;
}
if (!print_type) {
out("{}", StringView(data_and_type.data));
// Append a newline to text contents, unless the caller says otherwise.
if (data_and_type.mime_type.starts_with("text/") && !no_newline)
outln();
} else {
outln("{}", data_and_type.mime_type);
}
return 0;
}