Creating new programs

When creating new programs to access large POSIX files:

• Place the following Define statement in front of the first Include statement:

  #define _LARGEFILE64_SOURCE 1

• Specify the header unistd.h as the first Include statement.
  Then the program will have all interfaces and data types it needs available to it.

• Use the 64-bit functions to access large POSIX files, i.e. simply use open64(), lseek64(), ... instead of the normal functions open(), lseek(),... . 
  The following list provides an overview of all 64-bit functions:

  creat64()	fstat64()	lseek64()	stat64()
  fgetpos64()	fstatvfs64()	lstat64()	statvf64()s
  fopen64()	ftell64()	mmap64()	statvfs64()
  freopen64()	ftruncate64()	open64()	truncate64()
  fseek64()	getdents64()	readdir64()
  fsetpos64()	getrlimit64()	setrlimit64()

• Use the 64-bit data types in the program instead of the 32-bit data types, e.g. off64_t (64-Bit) instead of off_t (32-Bit). These data types are defined in the Include file sys/types.h. This allows the 64-bit and 32-bit interfaces to be used in parallel in a program, e.g. lseek() and lseek64(). This facilitates migration of programs.