@os

Import this module with import @os.

Environment Variables

Function	Signature	Description
get_env	(name string) -> string	Get environment variable. Returns "" for both an unset variable and one explicitly set to ""
lookup_env	(name string) -> (string, bool)	Get environment variable and whether it is actually set, distinguishing an unset variable from one set to ""
set_env	(name string, value string)	Set environment variable
unset_env	(name string)	Remove environment variable
environ	() -> [string]	Every environment variable of the current process, as "KEY=VALUE" strings

System Information

Function	Signature	Description
args	() -> [string]	Get command-line arguments
current_dir	() -> string	Get current working directory
home_dir	() -> string	Get the current user’s home directory ($HOME on Unix, %USERPROFILE% on Windows)
hostname	() -> string	Get machine hostname
pid	() -> i64	Get process ID
current_os	() -> Platform	Get the current OS as a Platform enum value
arch	() -> string	Get CPU architecture
cpu_count	() -> i64	Number of logical CPUs available to the process; falls back to 1
is_tty	() -> bool	True if standard output is a terminal (not a file or pipe)

Process Execution

Function	Signature	Description
exec	(cmd string, args [string]) -> (i64, string, string, bool)	Run a subprocess. Returns (exit_code, stdout, stderr, ok). ok is false if the process could not be launched. stdout and stderr are captured. POSIX only.

import @os

do main() {
    mut code, stdout, stderr, ok = os.exec("ls", {"-l", "/tmp"})
    if !ok {
        println("failed to launch")
    }
    if ok && code != 0 {
        println("exited with error: ${stderr}")
    }
}

Platform Enum

os provides the Platform enum for the mutually-exclusive host-OS values. Reachable as os.MAC_OS or Platform.MAC_OS (both denote the same value); returned by current_os(). Underlying values: MAC_OS 0, LINUX 1, WINDOWS 2, OTHER 3. Platform is reserved as a type name only while @os is imported.

import @os

do main() {

when os.current_os() {
    is .LINUX { println("linux") }
    is .MAC_OS { println("macos") }
    default   { println("other") }
}
}