PyAlias

Fast, persistent command aliases for Windows that work exactly like native commands.

Features

✓ Native behavior - Works in cmd.exe, PowerShell, Git Bash, any terminal
✓ Persistent - Survives restarts and terminal sessions
✓ Fast - 21x faster than .bat files (0.75ms vs 15ms per execution)
✓ Reliable - Works correctly with arguments in automation scripts
✓ Auto-install - Adds itself to PATH automatically
✓ Simple - 200 lines of Python, 200 lines of C

Installation

pip install git+https://github.com/offerrall/PyAlias-Windows-Alias-Manager

Requirements:

• Windows
• Python 3.10+
• gcc (MinGW-w64) - Download here

On first run, PyAlias automatically adds ~/.pyalias to your PATH. Restart your terminal after installation.

Quick Start

# Create aliases
pyalias new ls "dir /b"
pyalias new gs "git status"
pyalias new gp "git push"
pyalias new dev "cd C:\projects && npm run dev"

# Use them
ls
gs
gp origin main

# Manage
pyalias list
pyalias read ls
pyalias delete ls

Commands

pyalias new <alias> <command>    # Create alias
pyalias list                     # List all aliases  
pyalias read <alias>             # Show alias command
pyalias delete <alias>           # Delete alias
pyalias -h                       # Help

Why Not Just Use .bat Files?

You might wonder: "Windows already supports .bat files, why do I need this?"

.bat files have critical limitations:

1. 20x slower - Batch files take ~15ms to execute vs ~0.75ms for .exe

2. Arguments break in automation - .bat files don't pass arguments correctly when called from Python's subprocess

   • Your automation scripts will fail
   • .exe works reliably everywhere

3. Batch syntax quirks - Need @echo off, special escaping for %, &, |

   • .exe just runs the command directly

Benchmark from real tests:

100 executions in cmd.exe:
  .exe:  75ms   (0.75ms each)
  .bat:  1579ms (15.79ms each)
  
Result: .exe is 21x faster

How It Works

When you create an alias:

1. PyAlias copies launcher.exe → ~/.pyalias/ls.exe
2. Creates ~/.pyalias/ls.txt containing the command
3. Adds ~/.pyalias to your PATH (once)

When you run the alias:

1. Windows finds ls.exe in PATH
2. ls.exe reads its own filename: "ls"
3. Opens ls.txt in the same directory
4. Executes the command with any arguments you passed

User types:    ls -la
Executes:      ls.exe → reads ls.txt ("dir /b") → runs "dir /b -la"

Why C?

The launcher is written in C for speed and reliability:

• Instant execution - No interpreter overhead like batch files
• Static memory - No malloc, deterministic behavior
• Robust - Handles long paths (32KB), large commands (8KB)
• Portable - Single 20KB executable per alias

Technical Details

Launcher architecture:

• Static memory allocation (no malloc)
• 32KB path buffer (handles Windows long paths)
• 8KB command buffer (practically unlimited)
• Error handling with specific messages

Storage:

• Aliases stored in C:\Users\YourName\.pyalias\
• Each alias is one .exe + one .txt file
• 50 aliases = ~1MB total

Limitations

These are inherent to how subprocesses work, not PyAlias limitations:

• Can't change directory - cd in a subprocess doesn't affect the parent shell
• Can't modify environment - set VAR=value only affects the subprocess

For these use cases, use shell-specific solutions (.bashrc, PowerShell profiles, etc.)

Contributing

Pull requests welcome. Keep it simple and fast.

License

MIT