1 files changed, 163 insertions, 0 deletions
diff --git a/vtwrap.c b/vtwrap.c
new file mode 100644
index 0000000..be21433
--- /dev/null
+++ b/vtwrap.c
@@ -0,0 +1,163 @@
+#define _XOPEN_SOURCE 600
+#define _DEFAULT_SOURCE
+
+#include <sys/select.h>
+#include <sys/wait.h>
+#include <sys/epoll.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <unistd.h>
+#include <pty.h>
+#include <errno.h>
+
+#include <err.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+static char buf[BUFSIZ] = { 0 };
+
+static int
+writeall(int fd, char *buffer, size_t size)
+{
+	ssize_t nbytes;
+
+	while (size) {
+		nbytes = write(fd, buffer, size);
+		if (nbytes <= 0) return 1;
+		buffer += nbytes;
+		size -= nbytes;
+	}
+
+	return 0;
+}
+
+static int
+fwd(int in, int out)
+{
+	static char *buffer = NULL;
+	ssize_t got, i, last;
+
+	if (!buffer) {
+		buffer = malloc(BUFSIZ);
+		if (!buffer) err(1, "malloc");
+	}
+
+	do {
+		got = read(in, buffer, sizeof(buffer));
+		if (got < 0) return 1;
+
+		if (writeall(out, buffer, got))
+			return 1;
+	} while (got == sizeof(buffer));
+
+	return 0;
+}
+
+static void
+mitm(int pts)
+{
+	fd_set fds;
+
+	while (1) {
+		FD_ZERO(&fds);
+		FD_SET(0, &fds);
+		FD_SET(pts, &fds);
+
+		if (select(pts + 1, &fds, 0, 0, 0) == -1) {
+			if (errno == EINTR) continue;
+			return;
+		}
+
+		if (FD_ISSET(0, &fds)) { /* stdin -> ptty */
+			if (fwd(0, pts)) return;
+		}
+
+		if (FD_ISSET(pts, &fds)) { /* ptty -> stdout + pipe */
+			if (fwd(pts, 1)) return;
+		}
+	}
+}
+
+static void
+usage(int rc)
+{
+
+	fprintf(stderr, "Usage: apty [-r ROWS] [-c COLS] [-h] [--] CMD\n");
+	exit(rc);
+}
+
+int
+main(int argc, char **argv)
+{
+	char **arg, **cmd;
+	struct termios termios = {0};
+	struct winsize winsize = {0};
+	int exitcode;
+	int master, tty;
+	pid_t child;
+
+	if (argc <= 1) usage(1);
+
+	winsize.ws_col = 120;
+	winsize.ws_row = 80;
+	cfmakeraw(&termios);
+
+	if (isatty(STDIN_FILENO)) {
+		if (ioctl(STDIN_FILENO, TIOCGWINSZ, &winsize))
+			err(1, "tcgetwinsize");
+
+		if (tcgetattr(STDIN_FILENO, &termios))
+			err(1, "tcgettattr");
+		termios.c_lflag &= ~ICANON;
+		if (tcsetattr(STDIN_FILENO, TCSANOW, &termios))
+			err(1, "tcsetattr");
+	}
+
+	for (arg = argv + 1; *arg; arg++) {
+		if (!strcmp(*arg, "-t") || !strcmp(*arg, "--tty")) {
+			if (!isatty(STDIN_FILENO)) {
+				tty = open("/dev/tty", O_RDONLY);
+				if (tty < 0) err(1, "open /dev/tty");
+
+				if (tcgetattr(tty, &termios))
+					err(1, "tcgetattr tty");
+
+				if (ioctl(tty, TIOCGWINSZ, &winsize))
+					err(1, "tcgetwinsize tty");
+
+				close(tty);
+			}
+		} else if (!strcmp(*arg, "-c") || !strcmp(*arg, "--cols")) {
+			winsize.ws_col = atoi(*++arg);
+		} else if (!strcmp(*arg, "-r") || !strcmp(*arg, "--rows")) {
+			winsize.ws_row = atoi(*++arg);
+		} else if (!strcmp(*arg, "-h") || !strcmp(*arg, "--help")) {
+			usage(0);
+		} else if (!strcmp(*arg, "--")) {
+			arg++;
+			break;
+		} else {
+			break;
+		}
+	}
+
+	if (!*arg) errx(1, "missing command");
+	cmd = arg;
+
+	child = forkpty(&master, NULL, &termios, &winsize);
+	if (child < 0) err(1, "fork");
+
+	if (child == 0) {
+		execvp(*cmd, cmd);
+		err(1, "execvp %s", *cmd);
+	} else {
+		mitm(master);
+
+		waitpid(child, &exitcode, 0);
+		close(master);
+	}
+
+	return exitcode;
+}