View Source StringIO (Elixir v1.12.0-rc.0)
Controls an IO device process that wraps a string.
A StringIO
IO device can be passed as a "device" to
most of the functions in the IO
module.
Examples
iex> {:ok, pid} = StringIO.open("foo")
iex> IO.read(pid, 2)
"fo"
Link to this section Summary
Functions
Returns a specification to start this module under a supervisor.
Stops the IO device and returns the remaining input/output buffers.
Returns the current input/output buffers for the given IO device.
Flushes the output buffer and returns its current contents.
Creates an IO device.
Creates an IO device.
Link to this section Functions
Returns a specification to start this module under a supervisor.
See Supervisor
.
Stops the IO device and returns the remaining input/output buffers.
Examples
iex> {:ok, pid} = StringIO.open("in")
iex> IO.write(pid, "out")
iex> StringIO.close(pid)
{:ok, {"in", "out"}}
Returns the current input/output buffers for the given IO device.
Examples
iex> {:ok, pid} = StringIO.open("in")
iex> IO.write(pid, "out")
iex> StringIO.contents(pid)
{"in", "out"}
Flushes the output buffer and returns its current contents.
Examples
iex> {:ok, pid} = StringIO.open("in")
iex> IO.write(pid, "out")
iex> StringIO.flush(pid)
"out"
iex> StringIO.contents(pid)
{"in", ""}
@spec open(binary(), keyword()) :: {:ok, pid()}
@spec open(binary(), (pid() -> res)) :: {:ok, res} when res: var
Creates an IO device.
string
will be the initial input of the newly created
device.
options_or_function
can be a keyword list of options or
a function.
If options are provided, the result will be {:ok, pid}
, returning the
IO device created. The option :capture_prompt
, when set to true
, causes
prompts (which are specified as arguments to IO.get*
functions) to be
included in the device's output.
If a function is provided, the device will be created and sent to the
function. When the function returns, the device will be closed. The final
result will be a tuple with :ok
and the result of the function.
Examples
iex> {:ok, pid} = StringIO.open("foo")
iex> IO.gets(pid, ">")
"foo"
iex> StringIO.contents(pid)
{"", ""}
iex> {:ok, pid} = StringIO.open("foo", capture_prompt: true)
iex> IO.gets(pid, ">")
"foo"
iex> StringIO.contents(pid)
{"", ">"}
iex> StringIO.open("foo", fn pid ->
...> input = IO.gets(pid, ">")
...> IO.write(pid, "The input was #{input}")
...> StringIO.contents(pid)
...> end)
{:ok, {"", "The input was foo"}}
Creates an IO device.
string
will be the initial input of the newly created
device.
The device will be created and sent to the function given.
When the function returns, the device will be closed. The final
result will be a tuple with :ok
and the result of the function.
Options
:capture_prompt
- if set totrue
, prompts (specified as arguments toIO.get*
functions) are captured in the output. Defaults tofalse
.:encoding
(since v1.10.0) - encoding of the IO device. Allowed values are:unicode
(default) and:latin1
.
Examples
iex> StringIO.open("foo", [], fn pid ->
...> input = IO.gets(pid, ">")
...> IO.write(pid, "The input was #{input}")
...> StringIO.contents(pid)
...> end)
{:ok, {"", "The input was foo"}}
iex> StringIO.open("foo", [capture_prompt: true], fn pid ->
...> input = IO.gets(pid, ">")
...> IO.write(pid, "The input was #{input}")
...> StringIO.contents(pid)
...> end)
{:ok, {"", ">The input was foo"}}