Process context

The os module allows you to inspect the host environment, user accounts, current working directories, and process identifiers of the executing script.

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Host and User Context

You can query host properties and user account information using the following attributes and functions:

Attribute / Function	Alias	Purpose
os.hostname()	hostname()	Returns the system hostname.
os.user.name	username()	Returns the username of the current user.
os.user.id	userid()	Returns the user ID (UID) of the current user.
os.user.gid	groupid()	Returns the primary group ID (GID) of the current user.
os.user.home	home()	Returns the home directory path of the current user.

Example

def print_context():
    # Query host context
    printf("Host: %s\n", os.hostname())

    # Query user context
    printf("User: %s (UID: %s, GID: %s)\n", os.user.name, os.user.id, os.user.gid)
    printf("Home Directory: %s\n", os.user.home)

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Environment and Directory Management

You can inspect and modify the script's environment variables and current working directory. Any modifications apply to the script's process and any subsequent sub-processes it spawns.

• os.env(name, [default]) (Alias: env): Retrieves the value of an environment variable. Returns the optional default value if the variable is not set.
• os.setenv(name, value) (Alias: setenv): Sets the value of an environment variable.
• os.cwd() (Alias: cwd): Returns the absolute path of the current working directory.
• os.chdir(path) (Alias: chdir): Changes the current working directory for relative path operations and sub-process execution.

Example

def manage_environment():
    # Read and modify environment
    port = os.env("APP_PORT", "8080")
    os.setenv("PORT", port)

    # Manage working directory
    original_dir = os.cwd()
    os.chdir("/tmp")
    # Relative actions run under /tmp here
    os.chdir(original_dir)

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Executable Resolution and Process IDs

You can retrieve the process identifiers of the running script and locate binaries in the system PATH.

• os.pid() (Alias: pid): Returns the process ID of the running script.
• os.ppid() (Alias: ppid): Returns the parent process ID.
• os.which(name) (Alias: which): Locates an executable in the system PATH. Returns None if the executable is not found.

Example

def inspect_process():
    # Check process context
    printf("PID: %d (Parent PID: %d)\n", os.pid(), os.ppid())

    # Locate binary paths before execution
    git_path = os.which("git")
    if git_path:
        printf("Found git at: %s\n", git_path)
    else:
        fail("git is required but not installed on PATH")