OpenTrick

• Examples
• Supported Interfaces in Base
• OpenTrick.jl Documentation

There are some open methods which only support the open() do io ... end conventions. This module provides a trick to enable keeping io for later usage. This is convenient for interactive programming.

using WebSockets as an example.

using OpenTrick
using WebSockets

io = opentrick(WebSockets.open, "ws://echo.websocket.org");
write(io, "Hello");
println(String(read(io)));

close(io)  # you can close io manually
io = nothing; # or leave it to GC
unsafe_clear() # or you can clear all ios opened by opentrick manually

• read, read!, readbytes!, unsafe_read, readavailable, readline, readlines, eachline, readchomp, readuntil, bytesavailable
• write, unsafe_write, truncate, flush, print, println, printstyled, showerror
• seek, seekstart, seekend, skip, skipchars, position
• mark, unmark, reset, ismarked
• isreadonly, iswritable, isreadable, isopen, eof
• countlines, displaysize

# OpenTrick.opentrick — Function.

opentrick(openfn[, args... [; <keyword arguments>]])

Call openfn with (handlefn, args... ,kwargs ...) as arguments, return an IOWrapper instance. (NB:handlefn is provided by opentrick.)

Arguments

• openfn::Function function actually called to obtain a IO instance. openfn must take a Function(::IO) instance as its first argument
• args optional arguments that will be passed to openfn
• kwargs optional keyword arguments that will be passed to openfn

Examples

julia> using OpenTrick

julia> filename = tempname();

julia> io = opentrick(open, filename, "w+");

julia> write(io, "hello world!")
12

julia> seek(io, 0);

julia> readline(io)
"hello world!"

source

# OpenTrick.rawio — Function.

rawio(io)

Return the actual io instance

source

# OpenTrick.blockingtask — Function.

blockingtask(io)

Return the task blocking which prevents the handlefn passed to openfn from returning

source

# OpenTrick.unsafe_clear — Function.

unsafe_clear()

Unblock all blocking tasks. All ios returned by opentrick will be closed as a consequence.

source