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#include <cerrno>
#include <cstdio>
#include <cstring>
#include <exception>
#include <fcntl.h>
#include <functional>
#include <sdeventplus/event.hpp>
#include <sdeventplus/source/event.hpp>
#include <sdeventplus/source/io.hpp>
#include <sdeventplus/source/signal.hpp>
#include <signal.h>
#include <sys/epoll.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
void reader(const char* fifo, sdeventplus::source::IO& source, int fd, uint32_t)
{
char buf[4096];
ssize_t r = read(fd, buf, sizeof(buf));
if (r == 0)
{
int newfd = open(fifo, O_NONBLOCK | O_RDONLY);
if (newfd < 0)
{
fprintf(stderr, "Failed to open %s: %s\n", fifo, strerror(errno));
source.get_event().exit(1);
return;
}
source.set_fd(newfd);
if (close(fd))
{
fprintf(stderr, "Failed to close fd\n");
source.get_event().exit(1);
return;
}
return;
}
if (r < 0)
{
fprintf(stderr, "Reader error: %s\n", strerror(errno));
source.get_event().exit(1);
return;
}
printf("%.*s", static_cast<int>(r), buf);
}
void remover(const char* fifo, sdeventplus::source::EventBase& source)
{
int r = unlink(fifo);
if (r)
{
fprintf(stderr, "Failed to remove fifo %s: %s\n", fifo,
strerror(errno));
source.get_event().exit(1);
}
}
void clean_exit(sdeventplus::source::Signal& source,
const struct signalfd_siginfo*)
{
source.get_event().exit(0);
}
int main(int argc, char* argv[])
{
if (argc != 2)
{
fprintf(stderr, "Usage: %s [named pipe to create]\n", argv[0]);
return 1;
}
const char* fifo = argv[1];
// Block all signals before changing system state so we guarantee our clean
// up routines are in place
sigset_t signals;
if (sigfillset(&signals))
{
fprintf(stderr, "Failed to populate signals: %s\n", strerror(errno));
return 1;
}
if (sigprocmask(SIG_BLOCK, &signals, nullptr))
{
fprintf(stderr, "Failed to mask signals: %s\n", strerror(errno));
return 1;
}
if (mkfifo(fifo, 0622))
{
fprintf(stderr, "Failed to mkfifo %s: %s\n", fifo, strerror(errno));
return 1;
}
int fd = open(fifo, O_NONBLOCK | O_RDONLY);
if (fd < 0)
{
fprintf(stderr, "Failed to open %s: %s\n", fifo, strerror(errno));
return 1;
}
try
{
sdeventplus::Event event = sdeventplus::Event::get_default();
sdeventplus::source::Exit remover_source(
event, std::bind(remover, fifo, std::placeholders::_1));
sdeventplus::source::Signal sigint(event, SIGINT, clean_exit);
sdeventplus::source::IO reader_source(
event, fd, EPOLLIN,
std::bind(reader, fifo, std::placeholders::_1,
std::placeholders::_2, std::placeholders::_3));
return event.loop();
}
catch (const std::exception& e)
{
fprintf(stderr, "%s\n", e.what());
return 1;
}
}
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