# Python Termios Module

The `termios` module provides an interface to the POSIX calls for tty I/O control. For a complete description of these calls, see the termios(3) Unix manual page. It is only available on Unix.

## Importing the Module

```python
import termios
```

## Functions

### `termios.tcgetattr(fd)`

Returns a list containing the tty attributes for file descriptor `fd`.

```python
# Returns: [iflag, oflag, cflag, lflag, ispeed, ospeed, cc]
```

### `termios.tcsetattr(fd, when, attributes)`

Set the tty attributes for file descriptor `fd`. The `attributes` argument is a list like the one returned by `tcgetattr()`. The `when` argument determines when the attributes are changed.

Common `when` constants:
*   `termios.TCSANOW`: Change attributes immediately.
*   `termios.TCSADRAIN`: Change attributes after transmitting all queued output.
*   `termios.TCSAFLUSH`: Change attributes after transmitting all queued output and discarding all queued input.

## Example: Disabling Echo

This example demonstrates how to disable echoing of input characters (similar to entering a password).

```python
import termios
import sys

fd = sys.stdin.fileno()
old_settings = termios.tcgetattr(fd)

try:
    new_settings = termios.tcgetattr(fd)
    new_settings[3] = new_settings[3] & ~termios.ECHO # lflags
    termios.tcsetattr(fd, termios.TCSADRAIN, new_settings)
    
    password = input("Enter password (echo disabled): ")
finally:
    termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
    print(f"\nPassword entered: {password}")
```

[[programming/python/python]]