History Management

def read_history_file(filename=None):
    """
    Load a readline history file.
    
    Parameters:
    - filename (str, optional): Path to history file to read.
                               If None, defaults to ~/.history
    
    Returns:
    None
    
    Raises:
    IOError: If the file cannot be read
    """

def write_history_file(filename=None):
    """
    Save a readline history file.
    
    Parameters:
    - filename (str, optional): Path to history file to write.
                               If None, defaults to ~/.history
    
    Returns:
    None
    
    Raises:
    IOError: If the file cannot be written
    """

import readline
import atexit

# Load history at startup
try:
    readline.read_history_file()
except FileNotFoundError:
    pass  # No history file exists yet

# Save history at exit
atexit.register(readline.write_history_file)

# Use custom history file
readline.read_history_file('/path/to/custom_history')
readline.write_history_file('/path/to/custom_history')

def set_history_length(length):
    """
    Set the maximal number of items written to history file.
    
    Parameters:
    - length (int): Maximum history entries. Negative value inhibits truncation.
    
    Returns:
    None
    """

def get_history_length():
    """
    Return the maximum number of items that will be written to history file.
    
    Returns:
    int: Maximum history length (-1 means no limit)
    """

import readline

# Set history to 1000 entries
readline.set_history_length(1000)

# Disable history truncation
readline.set_history_length(-1)

# Check current limit
max_entries = readline.get_history_length()
print(f"History limit: {max_entries}")

def get_current_history_length():
    """
    Return the current (not maximum) length of history.
    
    Returns:
    int: Current number of history entries
    """

def get_history_item(index):
    """
    Return the current contents of history item at index.
    
    Parameters:
    - index (int): History item index (1-based on GNU readline, 
                   0-based on libedit/Apple systems)
    
    Returns:
    str: History line content, or None if index is invalid
    """

import readline

# Check current history size
current_size = readline.get_current_history_length()
print(f"Current history has {current_size} entries")

# Access recent history entries
if current_size > 0:
    # Get the most recent entry (last command)
    last_command = readline.get_history_item(current_size)
    print(f"Last command: {last_command}")
    
    # Show last 5 commands
    start = max(1, current_size - 4)
    for i in range(start, current_size + 1):
        command = readline.get_history_item(i)
        print(f"{i}: {command}")

def add_history(string):
    """
    Add a line to the history buffer.
    
    Parameters:
    - string (str): Line to add to history
    
    Returns:
    None
    """

def remove_history_item(pos):
    """
    Remove history item given by its position.
    
    Parameters:
    - pos (int): Position of history item to remove (0-based indexing)
    
    Returns:
    None
    """

def replace_history_item(pos, line):
    """
    Replace history item given by its position with contents of line.
    
    Parameters:
    - pos (int): Position of history item to replace (0-based indexing)
    - line (str): New content for history item
    
    Returns:
    None
    """

def clear_history():
    """
    Clear the current readline history.
    
    Returns:
    None
    
    Note: Only available when compiled with HAVE_RL_COMPLETION_APPEND_CHARACTER
    """

import readline

# Add custom entries to history
readline.add_history("ls -la")
readline.add_history("cd /tmp")
readline.add_history("python script.py")

# Replace a history entry (0-based indexing for manipulation)
readline.replace_history_item(0, "ls -la --color=auto")

# Remove unwanted history entry
readline.remove_history_item(1)  # Remove "cd /tmp"

# Clear all history
readline.clear_history()