# Module Scanf.Scanning

    module Scanning: sig .. end

###### Formatted input channel

    type in_channel

    type scanbuf = in_channel

The type of scanning buffers. A scanning buffer is the source from which a formatted input function gets characters. The scanning buffer holds the current state of the scan, plus a function to get the next char from the input, and a token buffer to store the string matched so far.

Note: a scanning action may often require to examine one character in advance; when this ``lookahead'' character does not belong to the token read, it is stored back in the scanning buffer and becomes the next character read.

    val stdin : in_channel

The standard input notion for the module `Scanf`. `stdin` is equivalent to `Scanning.from_channel Pervasives.stdin`.

Note: when input is read interactively from `stdin`, the newline character that triggers the evaluation is incorporated in the input; thus, scanning specifications must properly skip this character (simply add a `'\n'` as the last character of the format string).
Since 3.12.0

    val open_in : string -> in_channel

Bufferized file reading in text mode. The efficient and usual way to scan text mode files (in effect, `from_file` returns a scanning buffer that reads characters in large chunks, rather than one character at a time as buffers returned by `from_channel` below do). `Scanning.from_file fname` returns a scanning buffer which reads from the given file `fname` in text mode.
Since 3.12.0

    val open_in_bin : string -> in_channel

Bufferized file reading in binary mode.
Since 3.12.0

    val close_in : in_channel -> unit

Close the `Pervasives.input_channel` associated with the given `Scanning.in_channel`.
Since 3.12.0

    val from_file : string -> in_channel

An alias for `open_in` above.

    val from_file_bin : string -> in_channel

An alias for `open_in_bin` above.

    val from_string : string -> in_channel

`Scanning.from_string s` returns a formatted input channel which reads from the given string. Reading starts from the first character in the string. The end-of-input condition is set when the end of the string is reached.

    val from_function : (unit -> char) -> in_channel

`Scanning.from_function f` returns a scanning buffer with the given function as its reading method.

When scanning needs one more character, the given function is called.

When the function has no more character to provide, it must signal an end-of-input condition by raising the exception `End_of_file`.

    val from_channel : in_channel -> in_channel

`Scanning.from_channel ic` returns a formatted input channel which reads from the regular input channel `ic` argument, starting at the current reading position.

    val end_of_input : in_channel -> bool

`Scanning.end_of_input ic` tests the end-of-input condition of the given formatted input channel.

    val beginning_of_input : in_channel -> bool

`Scanning.beginning_of_input ic` tests the beginning of input condition of the given formatted input channel.

    val name_of_input : in_channel -> string

`Scanning.file_name_of_input ic` returns the name of the character source for the formatted input channel `ic`.
Since 3.09.0

    val stdib : in_channel

A deprecated alias for `Scanning.stdin`, the scanning buffer reading from `Pervasives.stdin`.