Initial commit

.gitignore

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+.DS_Store
+baud

baud.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <time.h>
+
+/*
+
+	baud - A tool to simulate a specified baud rate in a pipe.
+
+	I wrote this to be able to play some of the old VT100/ansi animations
+	at the rate of your choice.  Since most terminal emulator apps render
+	the text as fast as the system can (which is effectively instantaneous),
+	the animations do not actually animate.  This allows you to add 
+	a throttle to view as if you were on an actual serial terminal.
+
+	It takes one parameter, which is the desired baud rate.  If you do not
+	specify one, it will use the default defined below.  Extra parameters
+	will be ignored.
+
+	-- Scott Garrett
+	   version 2022050401
+
+*/
+
+#define defaultbaudrate	9600
+
+int main(int argc, char *argv[])
+{
+	int baudrate;
+	int c;
+
+	if ( argc == 1 )
+		baudrate = defaultbaudrate;
+	else
+		baudrate = atoi(argv[1]); 
+
+	/* Cannot have a negative baud rate, and 0 makes no sense
+	   (and would cause a division by zero).
+	*/
+	if ( baudrate <= 0 )
+	{
+		printf("Invalid baud rate: %d\n", baudrate);
+		exit(1);
+	}
+
+	/* Convert the desired baud rate into nanoseconds */
+	int baud = 10000000000 / baudrate;
+
+	/* Make sure the final value is in the valid range that nanosleep()
+	   supports.
+	*/
+	if ( baud < 0 || baud > 999999999 )
+	{
+		printf("Invalid baud rate: %d\n", baudrate);
+		exit(1);
+	}
+
+	/* Now that we know the desired baud rate delay in nanoseconds,
+	   load up the struct with the values.  0 seconds and the baud rate delay.
+	*/
+	struct timespec remaining, request = {0, baud};
+
+	while ((c = getchar()) != EOF)
+	{
+		/* Here we grab a character from stdin, write it, flush it out
+		   so it is seen immediately, then pause for "remaining" nanoseconds.
+		*/
+		putchar((char)c);
+		fflush(stdout);
+		int response = nanosleep(&request, &remaining);
+	}
+}

baudshell.py

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+#!/usr/bin/env python3
+"""pty_baud.py – run a shell behind two baud-rate simulators."""
+import os, pty, sys, tty, termios, select, subprocess
+
+BAUD  = sys.argv[1] if len(sys.argv) > 1 else "baud"
+SHELL = ["bash", "--norc"]
+
+master, slave = pty.openpty()
+shell = subprocess.Popen(SHELL, stdin=slave, stdout=slave, stderr=slave,
+                         preexec_fn=os.setsid, close_fds=True)
+os.close(slave)
+
+baud_out = subprocess.Popen([BAUD], stdin=subprocess.PIPE,
+                            stdout=subprocess.PIPE)
+baud_in  = subprocess.Popen([BAUD], stdin=subprocess.PIPE,
+                            stdout=subprocess.PIPE)
+
+# ── flatten every endpoint to an int fd ──────────────────────────
+fd_term          = sys.stdin.fileno()
+fd_baud_in_stdin = baud_in.stdin.fileno()
+fd_baud_in_out   = baud_in.stdout.fileno()
+fd_baud_out_in   = baud_out.stdin.fileno()
+fd_baud_out_out  = baud_out.stdout.fileno()
+# master is already an int from openpty()
+
+old = termios.tcgetattr(fd_term)
+tty.setraw(fd_term)
+
+def pump(r, w):
+    try:
+        d = os.read(r, 4096)          # r is already an int
+    except OSError:
+        return False
+    if not d:
+        return False
+    try:
+        os.write(w, d)                # w is already an int
+    except OSError:
+        return False
+    return True
+
+try:
+    while True:
+        r, _, _ = select.select(
+            [fd_term, master, fd_baud_in_out, fd_baud_out_out],
+            [], [], 0.01)
+
+        if fd_term          in r: pump(fd_term,          fd_baud_in_stdin)
+        if master           in r: pump(master,           fd_baud_out_in)
+        if fd_baud_in_out   in r: pump(fd_baud_in_out,   master)
+        if fd_baud_out_out  in r: pump(fd_baud_out_out,  fd_term)
+except KeyboardInterrupt:
+    pass
+finally:
+    termios.tcsetattr(fd_term, termios.TCSADRAIN, old)
+    for p in (shell, baud_in, baud_out):
+        try: p.terminate()
+        except OSError: pass
+