virtualshell 1.0.2

High-performance PowerShell bridge (C++ pybind11 backend)

virtualshell

High-performance Python façade over a C++ PowerShell runner.
A single long-lived PowerShell process is managed in C++, handling pipes, threads, timeouts and output demux; Python exposes a small, predictable API.

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Features

• Persistent session to pwsh/powershell (reuse modules, $env:*, functions, cwd)
• Sync & async execution (Futures + optional callbacks)
• Script execution (positional / named args, optional dot-sourcing)
• Batch with per-command timeout & early-stop
• Clear failures (typed exceptions), context manager lifecycle

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Install

pip install virtualshell

Platform & Python Support

Prebuilt wheels are provided via PyPI for common platforms and Python versions.
This means you can usually pip install virtualshell without needing a compiler.

Supported Python versions:

• 3.8, 3.9, 3.10, 3.11, 3.12, 3.13

Supported platforms:

• Windows (x86_64, MSVC build)
• Linux (x86_64, aarch64, manylinux2014/2.28)
• macOS (universal2: x86_64 + arm64)

If your platform is not listed above, pip will fall back to building from source.
See Building from source for details.

Requires PowerShell on PATH (pwsh preferred, powershell also supported).

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Quick start

import virtualshell

# Create a shell with a 5s default timeout
sh = virtualshell.Shell(timeout_seconds=5).start()

# 1) One-liners (sync)
res = sh.run("Write-Output 'hello'")
print(res.out.strip())  # -> hello

# 2) Async single command
fut = sh.run_async("Write-Output 'async!'")
print(fut.result().out.strip())

# 3) Scripts with positional args
r = sh.run_script(r"C:\temp\demo.ps1", args=["alpha", "42"])
print(r.out)

# 4) Scripts with named args
r = sh.run_script_kv(r"C:\temp\demo.ps1", named_args={"Name":"Alice","Count":"3"})
print(r.out)

# 5) Context manager (auto-stop on exit)
with virtualshell.Shell(timeout_seconds=3) as s:
    print(s.run("Write-Output 'inside with'").out.strip())

sh.stop()

Another example (stateful session):

from virtualshell import Shell
with Shell(timeout_seconds=3) as sh:
    sh.run("function Inc { $global:i++; $global:i }")
    nums = [sh.run("Inc").out.strip() for _ in range(5)]
    print(nums)  # ['1','2','3','4','5']

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API (overview)

import virtualshell
from virtualshell import ExecutionResult  # dataclass view

sh = virtualshell.Shell(
    powershell_path=None,                     # optional explicit path
    working_directory=None,                   # resolved to absolute path
    timeout_seconds=5.0,                      # default per-command timeout
    environment={"FOO": "BAR"},               # extra child env vars
    initial_commands=["$ErrorActionPreference='Stop'"],  # post-start setup
).start()

# Sync
res: ExecutionResult = sh.run("Get-Location | Select-Object -Expand Path")

# Scripts
res = sh.run_script(r"/path/to/job.ps1", args=["--fast","1"])
res = sh.run_script_kv(r"/path/to/job.ps1", named_args={"Mode":"Fast","Count":"1"})
res = sh.run_script(r"/path/init.ps1", dot_source=True)

# Async
f = sh.run_async("Write-Output 'ping'")
f2 = sh.run_async_batch(["$PSVersionTable", "Get-Random"])

# Convenience
res = sh.pwsh("literal 'quoted' string")     # safe single-quoted literal

sh.stop()

Return type

By default you get a Python dataclass:

@dataclass(frozen=True)
class ExecutionResult:
    out: str
    err: str
    exit_code: int
    success: bool
    execution_time: float

Pass as_dataclass=False to receive the raw C++ result object.

Timeouts

• Every method accepts a timeout (or per_command_timeout) in seconds.
• On timeout: success=False, exit_code=-1, err contains "timeout".
• Async futures resolve with the timeout result; late output is dropped in C++.

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Design notes

• Thin wrapper: heavy I/O in C++; Python does orchestration only.
• No surprises: stable API, documented side-effects.
• Clear failure modes: raise_on_error and typed exceptions.
• Thread-friendly: async returns Futures/callbacks; no Python GIL-level locking.
• Boundary hygiene: explicit path/arg conversions, minimal marshalling.

Security

• The wrapper does not sanitize raw commands. Only pwsh() applies literal single-quoting for data.
• Don’t pass untrusted strings to run* without proper quoting/sanitization.
• Avoid logging secrets; env injection happens via Shell(..., environment=...).

Performance

• Sync/async routes call into C++ directly; Python overhead is object creation + callback dispatch.
• Prefer batch/async for many small commands to amortize round-trips.

Lifetime

• Shell.start() ensures a running backend; Shell.stop() tears it down.
• with Shell(...) guarantees stop-on-exit, even on exceptions.

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Exceptions

from virtualshell.errors import (
    VirtualShellError,
    PowerShellNotFoundError,
    ExecutionTimeoutError,
    ExecutionError,
)

try:
    res = sh.run("throw 'boom'", raise_on_error=True)
except ExecutionTimeoutError:
    ...
except ExecutionError as e:
    print("PowerShell failed:", e)

• ExecutionTimeoutError is raised on timeouts if raise_on_error=True.
• Otherwise, APIs return ExecutionResult(success=False).

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Configuration tips

If PowerShell isn’t on PATH, pass powershell_path:

Shell(powershell_path=r"C:\Program Files\PowerShell\7\pwsh.exe")

Session setup example:

Shell(initial_commands=[
    "$OutputEncoding = [Console]::OutputEncoding = [Text.UTF8Encoding]::new()",
    "$ErrorActionPreference = 'Stop'"
])

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Building from source (advanced)

Source builds require a C++ toolchain and CMake.

Prereqs: Python ≥3.8, C++17, CMake ≥3.20, scikit-build-core, pybind11.

# in repo root
python -m pip install -U pip build
python -m build           # -> dist/*.whl, dist/*.tar.gz
python -m pip install dist/virtualshell-*.whl

Editable install:

python -m pip install -e .

• Linux wheels target manylinux_2_28 (x86_64/aarch64).
• macOS builds target universal2 (x86_64 + arm64).

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Roadmap

• ✅ Windows x64 wheels (3.8–3.13)
• ✅ Linux x64/aarch64 wheels (manylinux_2_28)
• ✅ macOS x86_64/arm64 wheels
• ⏳ Streaming APIs and richer progress events

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License

Apache 2.0 — see LICENSE.

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Issues & feedback are welcome. Please include Python version, OS, your PowerShell path (pwsh/powershell), and a minimal repro.