io

This module provides interfaces for working with to I/O stream and TTYs as well as expose the operating system standard I/O for easy access.

Some I/O operations that should belong to this module have been merged as core features and offered as built-in functions for Blade. Specifically file I/O features that can be accessed via the built-in file() function.

The standard I/O streams are also files and you can call almost all file methods on them. Whenever a file method is not supported, you’ll get an error message telling you that such operation is not supported for standard streams.

Example

The following example shows how to use the io module for accepting user name and printing the result.

import io

var name = io.readline('What is your name?')
echo name

Properties

io.SEEK_SET: Set I/O position from the beginning

io.SEEK_CUR: Set I/O position from the current position

io.SEEK_END: Set I/O position from the end

io.stdin: stdin is a file handle to the standard input file of the system

io.stdout: stdout is a file handle to the standard output file of the system

io.stderr: stderr is a file handle to the standard error file of the system

Functions

io.flush(file: file): flushes the content of the given file handle

io.putc(c: char | number): writes character c to the screen
return nil

io.getc(): reads character(s) from standard input
when length is given, gets length number of characters else, gets a single character

returns char | string

io.getch(): reads character(s) from standard input without printing to standard output
when length is given, gets length number of characters else, gets a single character

returns char | string

io.readline([message: string [, secure: bool = false [, obscure_text = ‘*’]]])

reads an entire line from standard input. If a messagge is given, the message will be printed before it begins to wait for a user input. If secure is true, the user’s input will not be printing and obscure_text will be printed instead.

newlines will not be added automatically for messages.

returns string

Classes

class TTY

class TTY is an interface to TTY terminals this class contains definitions to control TTY terminals

class TTY properties

static TTY.TTY_IFLAG: TTY attribute for input flags
static
static TTY.TTY_OFLAG: TTY attribute for output flags
static
static TTY.TTY_CFLAG: TTY attribute for control flags
static
static TTY.TTY_LFLAG: TTY attribute for local flags
static
static TTY.TTY_ISPEED: TTY attribute for input speed
static
static TTY.TTY_OSPEED: TTY attribute for output speed
static
static TTY.IGNBRK: ignore BREAK condition
static
static TTY.BRKINT: map BREAK to SIGINTR
static
static TTY.IGNPAR: ignore (discard) parity errors
static
static TTY.PARMRK: mark parity and framing errors
static
static TTY.INPCK: enable checking of parity errors
static
static TTY.ISTRIP: strip 8th bit off chars
static
static TTY.INLCR: map NL into CR
static
static TTY.IGNCR: ignore CR
static
static TTY.ICRNL: map CR to NL (ala CRMOD)
static
static TTY.IXON: enable output flow control
static
static TTY.IXOFF: enable input flow control
static
static TTY.IXANY: any char will restart after stop
static
static TTY.IUTF8: maintain state for UTF-8 VERASE
static
static TTY.OPOST: enable following output processing
static
static TTY.ONLCR: map NL to CR-NL (ala CRMOD)
static
static TTY.CSIZE: character size mask
static
static TTY.CS5: 5 bits (pseudo)
static
static TTY.CS6: 6 bits
static
static TTY.CS7: 7 bits
static
static TTY.CS8: 8 bits
static
static TTY.CSTOPB: send 2 stop bits
static
static TTY.CREAD: enable receiver
static
static TTY.PARENB: parity enable
static
static TTY.PARODD: odd parity, else even
static
static TTY.HUPCL: hang up on last close
static
static TTY.CLOCAL: ignore modem status lines
static
static TTY.ECHOE: visually erase chars
static
static TTY.ECHOK: echo NL after line kill
static
static TTY.ECHO: enable echoing
static
static TTY.ECHONL: echo NL even if ECHO is off
static
static TTY.ISIG: enable signals INTR, QUIT, [D]SUSP
static
static TTY.ICANON: canonicalize input lines
static
static TTY.IEXTEN: enable DISCARD and LNEXT
static
static TTY.TOSTOP: stop background jobs from output
static
static TTY.NOFLSH: don’t flush after interrupt
static
static TTY.TCSANOW: make change immediate
static
static TTY.TCSADRAIN: drain output, then change
static
static TTY.TCSAFLUSH: drain output, flush input
static
static TTY.VEOF: ICANON
static
static TTY.VEOL: ICANON
static
static TTY.VERASE: ICANON
static
static TTY.VKILL: ICANON
static
static TTY.VINTR: ISIG
static
static TTY.VQUIT: ISIG
static
static TTY.VSUSP: ISIG
static
static TTY.VSTART: IXON, IXOFF
static
static TTY.VSTOP: IXON, IXOFF
static
static TTY.VMIN: !ICANON
static
static TTY.VTIME: !ICANON
static

class TTY methods

TTY(std: file): constructor

file must be one of stdout and stderr

get_attr()

Returns the attribute of the current tty session The returned a attributes is a dict containing the TTY_ flags

set_attr(option: number, attrs: dict)

sets the attributes of the current tty session

option: one ot the TCSA options above (see their description above)
attrs a dictionary of the TTY_ flags listed above
one can safely omit any of the TTY_ flags listed above and Blade will fill in the default values as it exists.
- this flags will be merged and not overwritten

set_raw()

sets the current tty to raw mode

return bool

exit_raw()

disables the raw mode flags on the current tty

return bool

flush()

flushes the standard output and standard error interface