NAME
types — primitive system data types
DESCRIPTION
Remarks
The example given on this page is a typical version. The type names are
in general expected to be present, although exceptions (if any) may be
described in
DEPENDENCIES.
In most cases the fundamental type which implements each typedef
is implementation dependent as long as source code which uses
those typedefs need not be changed.
In some cases the typedef is actually a shorthand
for a commonly used type, and will not vary.
The data types defined in the include file
are used in
HP-UX
system code; some data of these types are accessible to user code:
typedef struct { int r[1]; } *physadr;
typedef char *caddr_t;
typedef unsigned int uint;
typedef unsigned short ushort;
typedef unsigned long ino_t;
typedef short cnt_t;
typedef long time_t;
typedef long dev_t;
typedef long off_t;
typedef long paddr_t;
typedef long key_t;
typedef int32_t pid_t;
typedef long uid_t;
typedef long gid_t;
typedef long blkcnt_t;
Note that the defined names above are standardized, but the actual type
to which they are defined may vary between
HP-UX
implementations.
The meanings of the types are:
- physadr
used as a pointer to memory; the pointer is aligned to follow
hardware-dependent instruction addressing conventions.
- caddr_t
used as an untyped pointer or a pointer to untyped memory.
- uint
shorthand for unsigned integer.
- ushort
shorthand for unsigned short.
- ino_t
used to specify I-numbers.
All native file systems (including HFS
and VxFS 3.5) through HP-UX 11i, use values that will fit within 32-bits.
Some remote NFS servers may use larger values, which will be truncated
without error for 32-bit applications and may not result in unique
values.
- cnt_t
used in some implementations to hold reference counts
for some kernel data structures.
- time_t
time encoded in seconds since 00:00:00 GMT, January 1, 1970.
- dev_t
specifies kind and unit number of a device,
encoded in two parts known as major and minor.
- off_t
offset measured in bytes from the beginning of a file.
If a 32-bit application is compiled with
-D_FILE_OFFSET_BITS=64
or
-D_LARGEFILE64_SOURCE,
off_t
will become an
int64_t.
- paddr_t
used as an integer type which is properly sized to hold a pointer.
- key_t
the type of a key used to obtain a message queue, semaphore, or shared memory
identifier, see
stdipc(3C).
- pid_t
used to specify process and process group identifiers.
- uid_t
used to specify user identifiers.
- gid_t
user to specify group identifiers.
- blkcnt_t
disk quota or transfer size measured in blocks.
If a 32-bit application is compiled with
-D_FILE_OFFSET_BITS=64
or
-D_LARGEFILE64_SOURCE,
blkcnt_t
will become an
int64_t.
STANDARDS CONFORMANCE
<sys/types.h>: AES, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1
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