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// Display images inside a terminal
// Copyright (C) 2023 JustKidding
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
#include "os.hpp"
#include "util/ptr.hpp"
#include <array>
#include <cstdlib>
#include <system_error>
#include <cerrno>
#include <cstdio>
#include <poll.h>
#include <unistd.h>
auto os::exec(const std::string &cmd) -> std::string
{
const int bufsize = 128;
std::array<char, bufsize> buffer{};
std::string result;
const c_unique_ptr<FILE, &pclose> pipe{popen(cmd.c_str(), "r")};
if (!pipe) {
throw std::system_error(errno, std::generic_category());
}
while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) {
result.append(buffer.data());
}
if (!result.empty()) {
result.erase(result.length() - 1);
}
return result;
}
auto os::read_data_from_fd(int filde, char sep) -> std::string
{
using std::errc;
std::string response;
char readch = 0;
while (true) {
const auto status = read(filde, &readch, 1);
if (status == -1) {
throw std::system_error(errno, std::system_category());
}
if (status == 0 || readch == sep) {
if (response.empty()) {
throw std::system_error(EIO, std::system_category());
}
break;
}
response.push_back(readch);
}
return response;
}
auto os::read_data_from_stdin(char sep) -> std::string
{
return read_data_from_fd(STDIN_FILENO, sep);
}
auto os::wait_for_data_on_fd(int filde, int waitms) -> bool
{
struct pollfd fds;
fds.fd = filde;
fds.events = POLLIN;
poll(&fds, 1, waitms);
if ((fds.revents & (POLLERR | POLLNVAL | POLLHUP)) != 0) {
throw std::system_error(EIO, std::generic_category());
}
return (fds.revents & POLLIN) != 0;
}
auto os::wait_for_data_on_stdin(int waitms) -> bool
{
return wait_for_data_on_fd(STDIN_FILENO, waitms);
}
auto os::getenv(const std::string &var) -> std::optional<std::string>
{
const char *env_p = std::getenv(var.c_str()); // NOLINT
if (env_p == nullptr) {
return {};
}
return env_p;
}
auto os::get_pid() -> int
{
return getpid();
}
auto os::get_ppid() -> int
{
return getppid();
}
void os::daemonize()
{
const int pid = fork();
if (pid < 0) {
std::exit(EXIT_FAILURE); // NOLINT
}
if (pid > 0) {
std::exit(EXIT_SUCCESS); // NOLINT
}
const int status = setsid();
if (status < 0) {
std::exit(EXIT_FAILURE); // NOLINT
}
}
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