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/* Copyright (c) 2018, Curtis McEnroe <programble@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/event.h>
#include <sys/ioctl.h>
#include <sysexits.h>
#include <termios.h>
#include <unistd.h>
static struct termios saveTerm;
static void restoreTerm(void) {
tcsetattr(STDOUT_FILENO, TCSADRAIN, &saveTerm);
}
static struct {
int read;
int write;
} winch;
static void sigwinch() {
struct winsize localWindow;
int error = ioctl(STDERR_FILENO, TIOCGWINSZ, &localWindow);
if (error) err(EX_IOERR, "ioctl(%d, TIOCGWINSZ, ...)", STDERR_FILENO);
ssize_t size = write(winch.write, &localWindow, sizeof(localWindow));
if (size < 0) err(EX_IOERR, "write(%d)", winch.write);
if ((size_t)size < sizeof(localWindow)) {
errx(EX_IOERR, "short write(%d)", winch.write);
}
}
static struct winsize remoteWindow;
static void readRemoteWindow(int remote) {
ssize_t size = read(remote, &remoteWindow, sizeof(remoteWindow));
if (size < 0) err(EX_IOERR, "read(%d)", remote);
if ((size_t)size < sizeof(remoteWindow)) errx(EX_IOERR, "short read(%d)", remote);
}
int main(int argc, char *argv[]) {
int error;
if (argc < 2) return EX_USAGE;
const char *path = argv[1];
int input = STDIN_FILENO;
int local = STDOUT_FILENO;
error = tcgetattr(local, &saveTerm);
if (error) err(EX_IOERR, "tcgetattr");
atexit(restoreTerm);
struct termios term = saveTerm;
term.c_lflag &= ~(ICANON | ECHO);
error = tcsetattr(local, TCSADRAIN, &term);
if (error) err(EX_IOERR, "tcsetattr");
error = pipe((int *)&winch);
if (error) err(EX_OSERR, "pipe");
signal(SIGWINCH, sigwinch);
sigwinch();
int remote = open(path, O_RDONLY);
if (remote < 0) err(EX_NOINPUT, "%s", path);
readRemoteWindow(remote);
int kq = kqueue();
if (kq < 0) err(EX_OSERR, "kqueue");
struct kevent events[3] = {
{ .ident = winch.read, .filter = EVFILT_READ, .flags = EV_ADD },
{ .ident = input, .filter = EVFILT_READ, .flags = EV_ADD },
{ .ident = remote, .filter = EVFILT_READ, .flags = EV_ADD },
};
int nevents = kevent(kq, events, 3, NULL, 0, NULL);
if (nevents < 0) err(EX_OSERR, "kevent");
char buf[4096];
bool truncated = false;
for (;;) {
struct kevent event;
int nevents = kevent(kq, NULL, 0, &event, 1, NULL);
if (nevents < 0) {
if (errno == EINTR) continue;
err(EX_OSERR, "kevent");
}
if (!nevents) continue;
if (event.ident == (uintptr_t)winch.read) {
for (;;) {
struct winsize localWindow;
ssize_t size = read(winch.read, &localWindow, sizeof(localWindow));
if (size < 0) err(EX_IOERR, "read(%d)", winch.read);
if ((size_t)size < sizeof(localWindow)) {
errx(EX_IOERR, "short read(%d)", winch.read);
}
if (
localWindow.ws_col == remoteWindow.ws_col
&& localWindow.ws_row == remoteWindow.ws_row
) break;
warnx(
"Please resize your terminal %hux%hu -> %hux%hu",
localWindow.ws_col, localWindow.ws_row,
remoteWindow.ws_col, remoteWindow.ws_row
);
}
}
if (event.ident == (uintptr_t)input) {
ssize_t size = read(input, buf, sizeof(buf));
if (size < 0) err(EX_IOERR, "read(%d)", input);
if (size == 1 && buf[0] == 'q') return EX_OK;
}
if (event.ident == (uintptr_t)remote) {
if (event.data < 0) {
off_t offset = lseek(remote, 0, SEEK_SET);
if (offset < 0) err(EX_IOERR, "lseek(%d)", remote);
truncated = true;
continue;
}
if (truncated) {
readRemoteWindow(remote);
sigwinch();
truncated = false;
continue;
}
ssize_t readSize = read(remote, buf, sizeof(buf));
if (readSize < 0) err(EX_IOERR, "read(%d)", remote);
ssize_t writeSize = write(local, buf, readSize);
if (writeSize < 0) err(EX_IOERR, "write(%d)", local);
if (writeSize < readSize) errx(EX_IOERR, "short write(%d)", local);
}
}
}
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