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Overview

CommandResult is a Pydantic model that encapsulates the output and status of a command executed on a guest VM. It is returned by vm.run() and provides both raw output streams and convenience properties.

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Fields

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exit_code
int
required
The exit code returned by the command. A value of 0 typically indicates success, while non-zero values indicate errors.
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stdout
str
required
The complete standard output captured from the command execution. This contains all text written to stdout by the process.
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stderr
str
required
The complete standard error output captured from the command execution. This contains all text written to stderr by the process.

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Properties

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ok

@property
def ok(self) -> bool:
    """Whether the command succeeded (exit_code == 0)."""
Convenience property that returns True if exit_code == 0, False otherwise. Example: 
result = vm.run("ls /tmp")
if result.ok:
    print("Command succeeded")
else:
    print(f"Command failed with code {result.exit_code}")

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output

@property
def output(self) -> str:
    """Convenience alias for stripped standard output."""
Returns stdout.strip(), removing leading and trailing whitespace. Useful for cleaner output in most cases. Example: 
result = vm.run("hostname")
print(f"Hostname: {result.output}")  # Clean output without newlines

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Usage Examples

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Basic Command Execution

from smolvm import VM

with VM() as vm:
    result = vm.run("echo 'Hello from SmolVM'")
    print(f"Exit Code: {result.exit_code}")
    print(f"Output: {result.stdout.strip()}")

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Error Handling

result = vm.run("ls /nonexistent")

if not result.ok:
    print(f"Command failed with exit code {result.exit_code}")
    print(f"Error: {result.stderr}")
else:
    print(f"Success: {result.output}")

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Checking Command Success

# Using the ok property
result = vm.run("apt-get update")
if result.ok:
    print("Update successful")
    
# Equivalent to checking exit code
if result.exit_code == 0:
    print("Update successful")

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Parsing Command Output

# Get list of files
result = vm.run("ls -1 /tmp")
if result.ok:
    files = result.output.split('\n')
    print(f"Found {len(files)} files")

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Handling Both Streams

result = vm.run("python script.py")

print("=== STDOUT ===")
print(result.stdout)

print("=== STDERR ===")
print(result.stderr)

print(f"=== EXIT CODE: {result.exit_code} ===")

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Immutability

CommandResult is a frozen Pydantic model, meaning instances are immutable after creation. This ensures the integrity of command results. 
result = vm.run("echo test")
# result.exit_code = 1  # This would raise an error

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