Built-in Mathematica Symbol

BinaryWrite

BinaryWrite[channel, b]
writes a byte of data, specified as an integer from 0 to 255.

BinaryWrite[channel, {b₁, b₂, ...}]
writes a sequence of bytes.

BinaryWrite[channel, "string"]
writes the raw sequence of characters in a string.

BinaryWrite[channel, x, type]
writes an object of the specified type.

BinaryWrite[channel, {x₁, x₂, ...}, type]
writes a sequence of objects of the specified type.

BinaryWrite[channel, {x₁, x₂, ...}, {type₁, type₂, ...}]
writes a sequence of objects with a sequence of types.

The output channel used by BinaryWrite can be a single file or pipe, or a list of them, each specified by a string giving its name, or by an OutputStream object that has been opened with BinaryFormat->True.

If any of the specified files or pipes are not already open, BinaryWrite calls OpenWrite to open them.

When a list of types is given, the list is effectively repeated as many times as necessary.

what byte ordering to use

BinaryWrite[channel, "string"] uses type "Character8", so all characters in "string" should have character codes in the range 0-255.

BinaryWrite returns $Failed if it encounters a data element that cannot match the type specified.

Create a file with a sequence of bytes:

Close the stream:

Read the first byte from the file: