UniBasic Commands Reference - Rocket Software

OSBREAD
Syntax
OSBREAD var FROM file.var [AT byte.expr] LENGTH length.expr [NODELAY]
[ON ERROR statements]
Description
The UniBasic OSBREAD command reads data from a file starting at a specified byte
location for a certain length of bytes, and assigns the data to a variable. OSBREAD
performs an operating system block read on a UNIX, or Windows platform file.
Note: Before you use OSBREAD, you must open the file by using the OSOPEN or
OPENSEQ command.
UniData uses the ASCII 0 character [CHAR(0)] as a string-end delimiter. Therefore,
ASCII 0 cannot be used in any string variable within UniBasic. OSBREAD converts
CHAR(0) to CHAR(128) when reading a block of data.
Reading from a Named Pipe
Keep these points in mind when you write programs that read from named pipes:
1-547 UniBasic Commands Reference
Unlike a typical read, reading a named pipe removes the data.
Your application should check the length of var after reading a pipe. The
value returned could be shorter than length.expr.
UniData truncates the data if it is longer than length.expr.
Reading Other Types of Files
Processing of files that are not named pipes is determined by the presence or absence
of the AT clause:
If the AT clause is included, UniBasic begins reading from the file at the
offset specified by byte.expr.