lfcompile64(5) Standards, Environments, and Macros lfcompile64(5)NAMElfcompile64 - transitional compilation environment
DESCRIPTION
All 64-bit applications can manipulate large files by default. The
transitional interfaces described on this page can be used by 32-bit
and 64-bit applications to manipulate large files.
In the transitional compilation environment, explicit 64-bit functions,
structures, and types are added to the API. Compiling in this environ‐
ment allows both 32-bit and 64-bit applications to access files whose
size is greater than or equal to 2 Gbyte ( 2^31 bytes).
The transitional compilation environment exports all the explicit
64-bit functions (xxx64()) and types in addition to all the regular
functions (xxx()) and types. Both xxx() and xxx64() functions are
available to the program source. A 32-bit application must use the
xxx64() functions in order to access large files. See the lf64(5) man‐
ual page for a complete listing of the 64-bit transitional interfaces.
The transitional compilation environment differs from the large file
compilation environment, wherein the underlying interfaces are bound to
64-bit functions, structures, and types. An application compiled in the
large file compilation environment is able to use the xxx() source
interfaces to access both large and small files, rather than having to
explicitly utilize the transitional xxx64() interface calls to access
large files. See the lfcompile(5) manual page for more information
regarding the large file compilation environment.
Applications may combine objects produced in the large file compilation
environment with objects produced in the transitional compilation envi‐
ronment, but must be careful with respect to interoperability between
those objects. Applications should not declare global variables of
types whose sizes change between compilation environments.
For applications that do not wish to conform to the POSIX or X/Open
specifications, the 64-bit transitional interfaces are available by
default. No compile-time flags need to be set.
Access to Additional Large File Interfaces
Applications that wish to access the transitional interfaces as well as
the POSIX or X/Open specification-conforming interfaces should use the
following compilation methods and set whichever feature test macros are
appropriate to obtain the desired environment (see standards(5)).
o Set the compile-time flag _LARGEFILE64_SOURCE to 1 before
including any headers.
o Use the getconf(1) command with one or more of the following
arguments:
┌──────────────────┬────────────────────────────────────────┐
│ argument │ purpose │
├──────────────────┼────────────────────────────────────────┤
│LFS64_CFLAGS │ obtain compilation flags necessary to │
│ │ enable the transitional compilation │
│ │ environment │
│LFS64_LDFLAGS │ obtain link editor options │
│LFS64_LIBS │ obtain link library names │
│LFS64_LINTFLAGS │ obtain lint options │
└──────────────────┴────────────────────────────────────────┘
EXAMPLES
In the following examples, the transitional compilation environment is
accessed by invoking the getconf utility with one of the arguments
listed in the table above. The additional large file interfaces are
accessed either by specifying -D_LARGEFILE64_SOURCE or by invoking the
getconf utility with the arguments listed above.
The example that uses the form of command substitution specifying the
command within parentheses preceded by a dollar sign can be executed
only in a POSIX-conforming shell such as the Korn Shell (see ksh(1)).
In a shell that is not POSIX-conforming, such as the Bourne Shell (see
sh(1)) and the C Shell (see csh(1)), the command must be enclosed
within grave accent marks.
Example 1 An example of compiling a program using transitional inter‐
faces such as lseek64() and fopen64():
$ c89 -D_LARGEFILE64_SOURCE \
$(getconf LFS64_CFLAGS) a.c \
$(getconf LFS64_LDFLAGS) \
$(getconf LFS64_LIBS)
Example 2 An example of running lint on a program using transitional
interfaces:
% lint -D_LARGEFILE64_SOURCE \
`getconf LFS64_LINTFLAGS` ... \
`getconf LFS64_LIBS`
SEE ALSOgetconf(1), lseek(2), fopen(3C), lf64(5), standards(5)SunOS 5.11 26 Jan 1998 lfcompile64(5)
