vtwrap

commit a760023437c0cf376ca3b030972009c48f3a7dee
Author: Louis Burda <quent.burda@gmail.com>
Date:   Sun, 12 Nov 2023 22:45:44 +0100

Initial prototype

Diffstat:
A
.gitignore
 | 
1
+
A
LICENSE
 | 
21
+++++++++++++++++++++
A
Makefile
 | 
21
+++++++++++++++++++++
A
apty.c
 | 
135
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

4 files changed, 178 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1 @@
+apty
diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Louis Burda
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/Makefile b/Makefile
@@ -0,0 +1,21 @@
+ifeq ($(DEBUG), 1)
+CFLAGS = -Og -g
+else
+CFLAGS = -O2
+endif
+
+.PHONY: all clean install uninstall
+
+all: apty
+
+apty: apty.c
+	$(CC) -o $@ $< $(CFLAGS) $(EXTRA_CFLAGS)
+
+clean:
+	rm -f apty
+
+install:
+	install -m755 apty -t "$(DESTDIR)$(PREFIX)$(BINDIR)"
+
+uninstall:
+	rm -f "$(DESTDIR)$(PREFIX)$(BINDIR)/apty"
diff --git a/apty.c b/apty.c
@@ -0,0 +1,135 @@
+#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 <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#define MAX_EVENTS 10
+
+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[8194];
+	ssize_t got, i, last;
+
+	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);
+
+		//fprintf(stderr, "?\n");
+		if (select(pts + 1, &fds, 0, 0, 0) == -1) {
+			if (errno == EINTR) continue;
+			return;
+		}
+
+		//fprintf(stderr, "!\n");
+
+		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;
+		}
+	}
+}
+
+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) errx(1, "missing args");
+
+	winsize.ws_col = 120;
+	winsize.ws_row = 80;
+	cfmakeraw(&termios);
+
+	if (isatty(0)) {
+		if (ioctl(0, TIOCGWINSZ, &winsize))
+			err(1, "tcgetwinsize");
+
+		if (tcgetattr(0, &termios))
+			err(1, "tcgettattr");
+		termios.c_lflag &= ~ICANON;
+		if (tcsetattr(0, TCSANOW, &termios))
+			err(1, "tcsetattr");
+	}
+
+	for (arg = argv + 1; *arg; arg++) {
+		if (!strcmp(*arg, "-w") || !strcmp(*arg, "--width"))
+			winsize.ws_col = atoi(*++arg);
+		else if (!strcmp(*arg, "-h") || !strcmp(*arg, "--height"))
+			winsize.ws_row = atoi(*++arg);
+		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;
+}