polybar-dwm/include/utils/io.hpp
2016-10-10 14:52:57 +02:00

121 lines
2.7 KiB
C++

#pragma once
#include <fcntl.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>
#include "common.hpp"
#include "utils/string.hpp"
LEMONBUDDY_NS
namespace io_util {
inline string read(int read_fd, int bytes_to_read, int& bytes_read_loc, int& status_loc) {
char buffer[BUFSIZ - 1];
if (bytes_to_read == -1)
bytes_to_read = sizeof(buffer);
status_loc = 0;
if ((bytes_read_loc = ::read(read_fd, &buffer, bytes_to_read)) == -1) {
throw system_error("Error trying to read from fd");
} else if (bytes_read_loc == 0) {
status_loc = -1;
} else {
buffer[bytes_read_loc] = '\0';
}
return {buffer};
}
inline string read(int read_fd, int bytes_to_read = -1) {
int bytes_read = 0;
int status = 0;
return read(read_fd, bytes_to_read, bytes_read, status);
}
inline string readline(int read_fd, int& bytes_read) {
std::stringstream buffer;
char char_;
bytes_read = 0;
while ((bytes_read += ::read(read_fd, &char_, 1)) > 0) {
buffer << char_;
if (char_ == '\n' || char_ == '\x00')
break;
}
if (bytes_read == 0) {
// Reached EOF
} else if (bytes_read == -1) {
// Read failed
} else {
return string_util::strip_trailing_newline(buffer.str());
}
return "";
}
inline string readline(int read_fd) {
int bytes_read;
return readline(read_fd, bytes_read);
}
inline size_t write(int write_fd, string data) {
return ::write(write_fd, data.c_str(), strlen(data.c_str()));
}
inline size_t writeline(int write_fd, string data) {
if (data.length() == 0)
return -1;
if (data.substr(data.length() - 1, 1) != "\n")
return io_util::write(write_fd, data + "\n");
else
return io_util::write(write_fd, data);
}
inline void tail(int read_fd, function<void(string)> callback) {
int bytes_read;
while (true) {
auto line = io_util::readline(read_fd, bytes_read);
if (bytes_read <= 0)
break;
callback(line);
}
}
inline void tail(int read_fd, int writeback_fd) {
tail(read_fd, [&writeback_fd](string data) { io_util::writeline(writeback_fd, data); });
}
inline bool poll(int fd, short int events, int timeout_ms = 1) {
struct pollfd fds[0];
fds[0].fd = fd;
fds[0].events = events;
::poll(fds, 1, timeout_ms);
return fds[0].revents & events;
}
inline bool poll_read(int fd, int timeout_ms = 1) {
return poll(fd, POLLIN, timeout_ms);
}
inline bool poll_write(int fd, int timeout_ms = 1) {
return poll(fd, POLLOUT, timeout_ms);
}
inline void interrupt_read(int write_fd) {
char end[1] = {'\n'};
::write(write_fd, end, 1);
}
}
LEMONBUDDY_NS_END