sys

The sys library provides access to system-specific parameters and functions. This is an extended library that must be explicitly registered.

Note: This library is enabled by default in the Scriptling CLI but must be manually registered when using the Go API.

Import

import sys

Available Constants

Constants

stdin

A file-like object connected to standard input. Only available when stdin is configured — either when running via the Scriptling CLI with piped input, or when an input is defined during registration of the sys library via the Go API.

sys.stdin is also iterable — each iteration yields one line including its newline:

import sys

# Read all at once
data = sys.stdin.read()

# Read line by line
line = sys.stdin.readline()

# Iterate over lines
for line in sys.stdin:
    print("Got:", line.rstrip())

platform

A string identifying the operating system platform.

import sys
print(sys.platform)  # "darwin", "linux", or "win32"

version

A string containing the version of the Scriptling interpreter.

import sys
print(sys.version)  # "Scriptling 1.0"

maxsize

The maximum value of a signed integer (int64).

import sys
print(sys.maxsize)  # 9223372036854775807

path_sep

The path separator used by the operating system.

import sys
print(sys.path_sep)  # "/" on Unix, "\" on Windows

argv

A list of command-line arguments passed to the script.

import sys
print(sys.argv)  # ["script.py", "arg1", "arg2"]

Functions

input([prompt])

Read a line from stdin, stripping the trailing newline. Only available when the environment is configured with a stdin reader.

line = input()
print("You typed:", line)

Note: The optional prompt argument is accepted but not printed (no interactive terminal in remote environments).

exit([code])

Raise a SystemExit exception to exit the interpreter.

Parameters:

• code - Exit status (default: 0). Can be an integer or a string message.

Behavior:

• Raises a SystemExit exception that can be caught with try/except
• If not caught, terminates the script execution with an error
• Integer codes produce exception message: “SystemExit: ”
• String messages produce exception with that message directly

import sys

# Exit successfully (raises SystemExit: 0)
sys.exit()

# Exit with error code (raises SystemExit: 1)
sys.exit(1)

# Exit with custom message
sys.exit("Fatal error occurred")

# Catching sys.exit to prevent termination
try:
    sys.exit(42)
    print("This won't run")
except Exception as e:
    print("Caught:", str(e))  # "Caught: SystemExit: 42"
    # Continue execution instead of exiting

package main

import (
    "fmt"
    "os"
    "github.com/paularlott/scriptling"
    "github.com/paularlott/scriptling/extlibs"
)

func main() {
    p := scriptling.New()

    // Register the sys library with argv
    extlibs.RegisterSysLibrary(p, []string{"script.py", "arg1", "arg2"})

    // Evaluate code that calls sys.exit()
    result, err := p.Eval(`
import sys
sys.exit(42)
    `)

    // Check for SystemExit error using helper
    if sysExit, ok := extlibs.GetSysExitCode(err); ok {
        fmt.Printf("Script exited with code: %d\n", sysExit.Code)
        os.Exit(sysExit.Code)  // Optionally exit the Go process
    } else if err != nil {
        fmt.Printf("Error: %v\n", err)
        os.Exit(1)
    }
}

import sys

if sys.platform == "darwin":
    print("Running on macOS")
elif sys.platform == "linux":
    print("Running on Linux")
elif sys.platform == "win32":
    print("Running on Windows")

import sys

if len(sys.argv) < 2:
    print("Usage: script.py <input_file>")
    sys.exit(1)

input_file = sys.argv[1]
print(f"Processing {input_file}")