Open System Services Programmer's Guide

An application can explicitly call a 64-bit function when you use the
#define _LARGEFILE64_SOURCE 1 feature test macro or an equivalent compiler command
option to compile the application.
An application call to interface() is automatically mapped to the interface64() function
when you use the #define _FILE_OFFSET_BITS 64 feature test macro or an equivalent
compiler command option to compile the application.
If a small file is accessed using a 64-bit API:
• The file is automatically converted to use an underlying Guardian file format of Format 2.
• The file no longer has a size limit of approximately 2 GB. It can grow to the size limit for large
files.
The LFA OSS APIs are:
creat64()
open64()
ftruncate64()
lseek64()
fcntl()
fstat64()
lstat64()
stat64()
fstatvfs64()
statvfs64()
readdir64()
ftw64()
nftw64()
glob()
The LFA native C run-time library APIs are:
__ns_backup_fopen64()
__ns_fopen64_special()
fgetpos64()
fopen64()
fopen64_guardian()
fopen64_oss()
fopen64_std_file()
freopen64()
freopen64_guardian()
freopen64_oss()
fseeko64()
fsetpos64()
ftello64()
scandir64()
tmpfile64()
tmpfile64_guardian()
tmpfile64_oss()
For H06.23 and earlier H-series RVUs or J06.12 and earlier J-series RVUs, the Native C++ run-time
libraries do not have new 64-bit specific APIs in the C++ library products. However, the logic
implementing IOStream classes is enhanced to be large OSS file safe for programs built with the
regular compilation environment or large OSS file aware for programs built with the large file
compilation environment (that is, macro _FILE_OFFSET_BITS is defined to have value 64.).
Accessing OSS Files Larger Than 2 GB 81