Reading And Writing Data To A File - Crestron SIMPL+ Reference Manual

Software
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118 SIMPL+

Reading and Writing Data to a File

Reading and writing data to a file that is moved from one kind of a system to another
has special programming considerations because it will likely be written on one kind
of system, e.g. a PC and read on another, e.g. a Crestron control system, or vice versa.
Most programmers are used to writing programs that are both written by a PC and
read by a PC.
The best way to write to a file that must be transferred between systems is to write
pure ASCII text and use the FileRead/FileWrite routines. If you must write binary
data as binary, e.g. structures, integers, strings, arrays, please read and consider the
following.
Different kinds of systems store their internal data structures with various padding
bytes and lengths, that are not always apparent. For example, a structure declared like
this:
STRUCTURE
{
STRING s[5];
INTEGER I;
}
may contain a padding byte between the string and the integer, so the integer can
begin on a word boundary. But this padding is system and compiler dependent, as
another system or compiler may handle this data perfectly well without a padding
byte. Also, some systems store integers with their most significant byte first (the
industry term is "big-endian") or with their least significant bytes first ("little-
endian").
Because compact flash is meant to be transferred among different systems, Crestron
has given the programmer two different ways to store data. It can be stored with
padding bytes by writing the integers, strings, structures, etc., directly (refer to
WriteInteger, WriteString, WriteStructure, WriteIntegerArray, etc) or it can be stored
directly as a string of bytes where the programmer controls exactly what is written
(refer to FileWrite). There are corresponding functions to read each of these. Data
written by one method should be read with the corresponding function. If you must
write binary files, Crestron recommends the first way, for system independence.
Details are listed in each function.
Crestron SIMPL+
Language Reference Guide - DOC. 5797G
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