stty 0.0.1

A Python library for manipulating terminal settings in the style of POSIX `stty(1)`.

stty.py

A Python library for manipulating terminal settings in the style of POSIX stty(1).

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Overview

stty provides a high-level, Pythonic interface to terminal I/O settings, including control characters, baud rates, and window size, using the termios and related modules. It allows you to get, set, save, and restore terminal attributes, and to apply them to file descriptors or pseudo-terminals.

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Features

• Read and modify terminal attributes (iflag, oflag, cflag, lflag, control characters, speeds, window size)
• Save and load settings to/from JSON files
• Apply settings to file descriptors or pseudo-terminals
• Symbolic and string-based access to all settings
• Emulates many stty(1) features and modes (e.g., raw, evenp, oddp, nl, ek)
• Cross-platform support (where termios is available)

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Installation

This is a pure Python library. Place stty.py in your project or install via your preferred method.

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Examples

1. Reading and Printing Terminal Settings

from stty import Stty

# Open terminal and get current settings from stdin (fd=0)
tty = Stty(fd=0)
print(tty)  # Print all settings in a compact form

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2. Setting Individual Attributes

from stty import Stty

tty = Stty(fd=0)

# Turn off echo
tty.echo = False

# Set erase character to Ctrl-H
tty.erase = "^H"

# Set input baud rate to 9600
tty.ispeed = 9600

# Set number of rows in the terminal window (if supported)
tty.rows = 40

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3. Setting Multiple Attributes at Once

from stty import Stty

tty = Stty(fd=0)

# Set several attributes in one call
tty.set(
    echo=False,
    icanon=False,
    erase="^H",
    ispeed=19200,
    ospeed=19200,
    rows=30,
    cols=100
)

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4. Saving and Loading Settings

from stty import Stty

tty = Stty(fd=0)

# Save current settings to a file
tty.save("my_tty_settings.json")

# Later, restore settings from the file
tty2 = Stty(path="my_tty_settings.json")
tty2.tofd(0)  # Apply to stdin

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5. Using Raw Mode

from stty import Stty

tty = Stty(fd=0)
tty.raw()         # Set raw mode
tty.tofd(0)       # Apply to stdin

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6. Working with Pseudo-terminals

from stty import Stty

tty = Stty(fd=0)
m, s, sname = tty.openpty()  # Open a new pty pair and apply settings to slave
print(f"Master fd: {m}, Slave fd: {s}, Slave name: {sname}")

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7. Setting Control Characters

from stty import Stty

tty = Stty(fd=0)

# Set interrupt character to Ctrl-C
tty.intr = "^C"

# Set end-of-file character to Ctrl-D
tty.eof = "^D"

# Set suspend character to DEL
tty.susp = "^?"

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8. Querying Settings as a Dictionary

from stty import Stty

tty = Stty(fd=0)
settings = tty.get()
print(settings["echo"])   # True or False
print(settings["erase"])  # e.g., '^H'

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9. Using Symbolic Constants

from stty import Stty, cs8, tab0

tty = Stty(fd=0)

# Set character size to 8 bits using symbolic constant
tty.csize = cs8

# Set tab delay to tab0
tty.tabdly = tab0

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10. Fork new process with pseudo-terminal

x = stty.Stty(0)
x.intr = "^p"
pid, m, sname  = x.forkpty()

if pid == 0: # Child process
    with open("out", "w") as f:
        f.write(str(stty.Stty(0)))
else: # Parent process
    print(sname)
    print("")
    s = os.open(sname, os.O_RDWR)
    print("Parent:", stty.Stty(s))
    os.close(s)

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API Reference

Classes

Stty

Manipulate terminal settings in the style of stty(1).

Constructor:

Stty(fd: int = None, path: str = None, **opts)

• fd: File descriptor to read settings from.
• path: Path to JSON file to load settings from.
• **opts: Any supported terminal attribute as a keyword argument.

Methods:

• get() -> dict Return a dictionary of all current settings.

• set(**opts) Set multiple attributes at once.

• save(path: str = None) Save settings to a JSON file, or return a deep copy if no path is given.

• load(path: str) Load settings from a JSON file.

• fromfd(fd: int) Load settings from a file descriptor.

• tofd(fd: int, when=TCSANOW, apply_termios=True, apply_winsize=True) Apply settings to a file descriptor.

• evenp(plus=True) Set/unset even parity mode.

• oddp(plus=True) Set/unset odd parity mode.

• raw() Set terminal to raw mode.

• nl(plus=True) Set/unset nl combination mode.

• ek() Set ek combination mode.

• openpty(apply_termios=True, apply_winsize=True) Open a new pseudo-terminal pair and apply settings.

• forkpty(apply_termios=True, apply_winsize=True) Fork a new process with a pseudo-terminal and apply settings.

Attribute Access:

• All terminal attributes (e.g., echo, icanon, erase, ispeed, rows, etc.) are accessible as properties.
• Setting an attribute updates the internal state and validates the value.

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Constants

• TCSANOW, TCSADRAIN, TCSAFLUSH: the values accepted by the when named argument of Stty.tofd(). Compare with termios.tcsetattr().
• Symbolic constants for masks and values (e.g., cs8, tab0, etc.) are available as module attributes.

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Data

• settings: A dictionary describing all available Stty attributes and their possible values on the current platform.

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Functions

• settings_help_str: Return help string about all available Stty attributes and their possible values on the current platform.
• settings_help: Print help message about all available Stty attributes and their possible values on the current platform.

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Compatibility

• Requires Python 3.x and a POSIX-like system with the termios module.
• Some features depend on platform support (e.g., window size).

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License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

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Author

Soumendra Ganguly, 2025

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See Also

• stty(1) manpage
• Python termios documentation