OS

The os module allows to access to some functionalities of the underlying operating system

All the given examples assume the following imports:

let os = import('std/os');
let io = import('std/io');

Functions

• sleep
• get_env
• set_env
• exec
• find_exec
• install
• get_cwd
• set_cwd
• mkdir
• rm
• copy
• chmod

Variables

• name

exists

os.sleep(ms: int) -> nil

Pauses the program execution for ms milliseconds. Please not that the exact sleep time might be greater than ms because of how OS scheduler works.

Example:

io.println('Waiting a bit...');
os.sleep(1000);
io.println('Done!');

Gives the output:

Waiting a bit...
# one second later
Done!

get_env

os.get_env(var: string) -> string

Returns the content of the environment variable var if it exists or an empty string otherwise

Example:

io.println('$HOME=', os.get_env('HOME'));

Possible output:

$HOME=/home/feral

set_env

os.set_env(var: string, value: string, overwite: bool = false) -> int

Sets the content of the environment variable var with the content of value. If var already exists, it won't be overwritten unless overwrite is true. The function returns 0 on success and -1 on error

Example:

io.println('$FOOBAR=', os.get_env('FOOBAR'));
os.set_env('FOOBAR', 'Hello');
io.println('$FOOBAR=', os.get_env('FOOBAR'));
os.set_env('FOOBAR', 'Hello, world!');
io.println('$FOOBAR=', os.get_env('FOOBAR'));
os.set_env('FOOBAR', 'Hello, world!', true);
io.println('$FOOBAR=', os.get_env('FOOBAR'));

Gives the ouput:

$FOOBAR=
$FOOBAR=Hello
$FOOBAR=Hello
$FOOBAR=Hello, world!

exec

os.exec(cmd: string) -> int

Executes the command cmd and returns its result. All text printed by cmd will be redirected to the standard output

Example:

io.println(os.exec('uname'));

Possible ouput:

Linux
0

find_exec

os.find_exec(exec: string) -> string

Search in PATH for the executable exec and returns its path if found or an empty string otherwise

Example:

io.println(os.find_exec('ls'));

Possible ouput:

/usr/bin/ls

install

os.install(src: string, dest: string) -> int

Copies all the content of the source file or folder src into dest. The path leading to dest will be created if necessary. The function returns 0 on success and -1 on error

Example:

os.install('/home/feral/Documents', '/mnt/backup');

get_cwd

os.get_cwd() -> string

Returns the current working directory

Example:

io.println(os.get_cwd());

Possible output:

/home/feral

set_cwd

os.set_cwd(wd: string) -> int

Changes the current working directory to be wd. The function returns 0 on success and -1 on error

Example:

io.println(os.get_cwd());
os.set_cwd('/home/feral/Documents');
io.println(os.get_cwd());

Possible output:

/home/feral
/home/feral/Documents

mkdir

os.mkdir(dir...: string) -> int

Creates all given directories. The function returns 0 on success and -1 on error

Example:

os.mkdir('/home/feral/Build', '/home/feral/Tests');

rm

os.rm(path...: string) -> int

Removes all given files and directories. The function returns 0 on success and -1 on error

Example:

os.rm('/home/feral/Build', '/home/feral/Tests');

copy

os.copy(src...: string, dest: string) -> int

Copies all given files and directories to dest. The function returns 0 on success and -1 on error

Example:

os.copy('/home/feral/Build', '/home/feral/Tests', '/tmp');

chmod

os.chmod(dest: string, mode: string = '755', recurse: bool = 'true') -> int

Changes the permission of dest to mode, and recursively to its content if recurse is true. The function returns 0 on success and -1 on error

Example:

os.chmod('/home/feral/Build', '777', false);

name

os.name: string

The name of the OS. Current possible values are linux, macos, bsd and android

Example:

io.println(os.name;

Possible ouput:

linux