os

The os module provides access to environment variables, process information, and command execution.

Functions¶

Function	Returns	Description
`os.env(name, default="")`	`string`	Get environment variable, with optional default
`os.setenv(name, value)`	`None`	Set environment variable
`os.cwd()`	`string`	Get current working directory
`os.chdir(path)`	`None`	Change current working directory
`os.hostname()`	`string`	Get system hostname
`os.pid()`	`int`	Get current process ID
`os.ppid()`	`int`	Get parent process ID
`os.exit(code=0)`	`None`	Exit the process with the given code
`os.exec(cmd, shell=None, env=None, cwd=None, timeout="60s")`	`ExecResult`	Execute a system command
`os.which(name)`	`string`/`None`	Find executable on PATH
`os.username()`	`string`	Get current username
`os.userid()`	`string`	Get current user ID
`os.groupid()`	`string`	Get current group ID
`os.home()`	`string`	Get home directory path

Global exec() Alias¶

The exec() function is available as a top-level global, equivalent to os.exec():

# These are identical
result = exec("ls -la")
result = os.exec("ls -la")

ExecResult¶

The ExecResult object returned by os.exec() and exec() has these attributes:

Attribute	Type	Description
`stdout`	`string`	Standard output of the command
`stderr`	`string`	Standard error of the command
`code`	`int`	Exit code (0 = success)
`ok`	`bool`	`True` if exit code is 0
`error`	`string`	Error message on failure; empty string when `ok` is `True`

Examples¶

Environment variables¶

home = os.env("HOME")
path = os.env("MY_VAR", "default_value")

os.setenv("DEPLOY_ENV", "production")

Process information¶

print("Host:", os.hostname())
print("User:", os.username())
print("PID:", os.pid())
print("CWD:", os.cwd())
print("Home:", os.home())

Command execution¶

# Simple command
result = exec("git status")
if result.ok:
    print(result.stdout)
else:
    print("Failed:", result.stderr)

# With options
result = os.exec(
    "make build",
    cwd="/home/user/project",
    env={"GOOS": "linux", "GOARCH": "amd64"},
    timeout="120s",
)

# Find an executable
go_path = os.which("go")
if go_path:
    print("Go found at:", go_path)

Changing directories¶

os.chdir("/tmp")
print(os.cwd())  # /tmp

Note: All os functions that can fail support try_ variants. For example, os.try_exec() returns a Result instead of raising on non-zero exit codes.