Run commands

env.run(...) takes one command string and waits for it to finish:

from sandweave import Sandbox

with Sandbox() as env:
    result = env.run("python -c 'print(2 + 2)'")
    print(result.stdout)
    print(result.stderr)
    print(result.returncode)

The command runs through /bin/sh -c inside the sandbox. Pipes, redirects, environment expansion, and && work as shell expressions there.

Working directory and environment

with Sandbox() as env:
    result = env.run("echo $MODE > result.txt && cat result.txt",
                     cwd="/workspace", env={"MODE": "evaluation"})
    print(result.stdout)

Each call starts a new process. A cd or export in one call does not change the next call. The default working directory is /workspace.

Exit codes and timeouts

from sandweave import CommandError, Sandbox

with Sandbox() as env:
    result = env.run("python -c 'raise ValueError(42)'")
    assert result.returncode != 0
    print(result.stderr)

    try:
        env.run("false", check=True)
    except CommandError as error:
        print(error.result.returncode)

Use timeout=5 to give a command a five-second execution deadline. A timeout raises CommandTimeout; it is separate from a program's nonzero exit status. startup_timeout on Sandbox(...) controls sandbox creation instead.

Stream a process

from sandweave import Sandbox

with Sandbox() as env:
    process = env.exec("python -u -c 'print(1); print(2)'")
    for line in process.stdout:
        print(line, end="")
    process.wait(check=True)

exec returns immediately with a Process. Use its stdin, stdout, stderr, poll(), wait(), and terminate() methods. The SDK drains command output within its configured output limit.

For a terminal, pass pty=True. Terminal stdout and stderr share one stream; process.resize(rows, cols) changes its dimensions.

Select a shell or literal arguments

with Sandbox() as env:
    print(env.run("printf '%s\\n' {1..3}", shell="/bin/bash").stdout)
    print(env.run(argv=["python", "-c", "print(2 + 2)"]).stdout)

Use argv when you need literal arguments without a shell. Do not combine it with a command string or the shell option.

Output limits

Commands have a 64 MiB combined output limit by default. Override it with max_output_bytes. Exceeding the limit terminates the command and raises OutputLimitExceeded with partial output. Download large result files through file access before terminating the sandbox.