os

This module provides functions for interfacing with the underlying operating system and directories.

Properties

os.platform

The name of the current platform in string or unknown if the platform name could not be determined.

type string

Example,

%> import os
%> os.platform
'osx'

os.args: A list containing the command line arguments passed to the startup script.
type list

os.path_separator: The standard path separator for the current operating system.
type string

os.exe_path: The full path to the running Blade executable.
type string

os.DT_UNKNOWN: Unknown file type
type number

os.DT_BLK: Block device file type
type number

os.DT_CHR: Character device file type
type number

os.DT_DIR: Directory file type
type number

os.DT_FIFO: Named pipe file type
type number

os.DT_LNK: Symbolic link file type
type number

os.DT_REG: Regular file type
type number

os.DT_SOCK: Local-domain socket file type
type number

os.DT_WHT

Whiteout file type (only meaningful on UNIX and some unofficial Linux versions).

type number

value is -1 on systems where it is not supported.

os.current_file: current_file()
A string containing the path to the current file from which the value is accessed.

type string

Functions

os.exec(cmd: string)

Executes the given shell (or command prompt for Windows) commands and returns the output as string.

return string

Example,

%> os.exec('ls -l')
'total 48
-rw-r--r--@ 1 username  staff  705 Aug 27  2021 buggy.b
-rw-r--r--  1 username  staff  197 Mar  5 05:13 myprogram.b'

os.info()

Returns information about the current operation system and machine as a dictionary. The returned dictionary will contain:

sysname: The name of the operating system
nodename The name of the current machine
version: The operating system version
release: The release level/version
machine: The hardware/processor type.

return dict

Example,

%> os.info()
{sysname: Darwin, nodename: MacBook-Pro.local, version: Darwin Kernel Version 
21.1.0: Wed Oct 13 17:33:24 PDT 2021; root:xnu-8019.41.5~1/RELEASE_ARM64_T8101, 
release: 21.1.0, machine: arm64}

os.sleep(duration: number): Causes the current thread to sleep for the specified number of seconds.

os.get_env(name: string)

Returns the given environment variable if exists or nil otherwise

return string

Example,

%> import os
%> os.get_env('ENV1')
'20'

os.set_env(name: string, value: string, overwrite: bool = true)

Sets the named environment variable to the given value.

return string

Example,

%> os.set_env('ENV1', 'New value')
true
%> os.get_env('ENV1')
'New value'

If you are in the REPL and have tried the last example in get_env(), you may notice that the value of ENV1 doesn’t change. This is because unless you specify, set_env() will not overwrite existing environment variables. For that, you will need to specify true as the third parameter to set_env().

For example,

%> os.set_env('ENV1', 'New value again', true)
true
%> os.get_env('ENV1')
'New value again'

Environment variables set will not persist after application exists.

os.create_dir(path: string, [permission: number = 0c777 [, recursive: boolean = true]])

Creates the given directory with the specified permission and optionaly add new files into it if any is given.

if the directory already exists, it returns false otherwise, it returns true.

permission should be given as octal number.

return boolean

os.read_dir(path: string)

Scans the given directory and returns a list of all matched files

return list[string]

Example,

%> os.read_dir('./tests')
[., .., myprogram.b, single_thread.b, test.b, buggy.b]

. indicates current directory and can be used as argument to os.path as well.

.. indicates parent directory and can be used as argument to os.path as well.

os.chmod(path: string, mod: number)

Changes the permission set on a directory

mod should be octal number (e.g. 0c777)

return boolean

os.is_dir(path: string): Returns true if the path is a directory or false otherwise.
return bool

os.remove_dir(path: string [, recursive: boolean = false]): Deletes a non-empty directory. If recursive is true, non-empty directories will have their contents deleted first.
return bool

os.cwd(): Returns the current working directory
return string

os.change_dir(path: string): Navigates the working directory into the specified path.
return bool

os.exists(path: string): Returns true if the directory exists or false otherwise.
return bool

os.exit(code: number): Exit the current process and quits the Blade runtime.
return

os.join_paths(paths…)

Concatenates the given paths together into a format that is valied on the current operating system.

return string

Example,

%> os.join_paths('/home/user', 'path/to/myfile.ext')
'/home/user/path/to/myfile.ext'

os.real_path(path: string)

returns the original path to a relative path.

if the path is a file, see abs_path()

return string

os.abs_path(path: string)

returns the original path to a relative path.

unlike real_path(), this function returns full path for a file

return string

os.dir_name(path: string): Returns the parent directory of the pathname pointed to by path. Any trailing / characters are not counted as part of the directory name. If path is an empty string, or contains no / characters, dir_name() returns the string “.”, signifying the current directory.
return string

os.base_name(path: string): The base_name() function returns the last component from the pathname pointed to by path, deleting any trailing / characters. If path consists entirely of / characters, the string ‘/’ is returned. If path is an empty string, the string ‘.’ is returned.
return string