Guardian Procedure Calls Reference Manual

FILE_READ64_ Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Returned Value
Considerations
Disk File Considerations
Related Programming Manuals
Summary
The FILE_READ64_ procedure returns data from an open file to the application process' data area.
FILE_READ64_ is intended for use with 64-bit extended addresses. The data buffer for FILE_READ64_
can be either in the caller's stack segment or any extended data segment.
FILE_READ64_ sequentially reads a disk file. For key-sequenced, relative, and entry-sequenced
files, FILE_READ64_ reads a subset of records in the file. (A subset of records is defined by an
access path, positioning mode, and comparison length.)
FILE_READ64_ extends the capabilities of READX in several ways:
• It permits the read buffer to reside outside of the 32-bit addressable range.
• It is callable from both 32-bit and 64-bit processes
• It allows for the capability to read more than 56kb in a single operation by widening the read
count to 32 bits.
• It allows the returned count-read argument to reside outside of the 32-bit addressable
range.
• It allows a 64-bit nowait I/O tag to be passed.
• Rather than returning a condition code status, the procedure returns a file management error.
A return value of zero indicates success.
NOTE: The FILE_READ64_ procedure is supported on systems running H06.24 and later H-series
RVUs and J06.13 and later J-series RVUs. Its use is recommended for new code.
Syntax for C Programmers
#include <cextdecs(FILE_READ64_)>
short FILE_READ64_ ( short filenum
,char _ptr64 *buffer
,__int32_t read-count
,[ __int32_t _ptr64 *count-read ]
,[ long long tag ] );
FILE_READ64_ Procedure 475