sys/types.h — data types
#include <sys/types.h>
The <sys/types.h> header shall define at least the following types:
- blkcnt_t
- Used for file block counts.
- blksize_t
- Used for block sizes.
- clock_t
- Used for system times in clock ticks or CLOCKS_PER_SEC; see <time.h>.
- clockid_t
- Used for clock ID type in the clock and timer functions.
- dev_t
- Used for device IDs.
- fsblkcnt_t
- Used for file system block counts.
- fsfilcnt_t
- Used for file system file counts.
- gid_t
- Used for group IDs.
- id_t
- Used as a general identifier; can be used to contain at least a pid_t, uid_t, or gid_t.
- ino_t
- Used for file serial numbers.
- key_t
- [XSI]
Used for XSI interprocess communication.
- mode_t
- Used for some file attributes.
- nlink_t
- Used for link counts.
- off_t
- Used for file sizes.
- pid_t
- Used for process IDs and process group IDs.
- pthread_attr_t
- Used to identify a thread attribute object.
- pthread_barrier_t
- Used to identify a barrier.
- pthread_barrierattr_t
- Used to define a barrier attributes object.
- pthread_cond_t
- Used for condition variables.
- pthread_condattr_t
- Used to identify a condition attribute object.
- pthread_key_t
- Used for thread-specific data keys.
- pthread_mutex_t
- Used for mutexes.
- pthread_mutexattr_t
- Used to identify a mutex attribute object.
- pthread_once_t
- Used for dynamic package initialization.
- pthread_rwlock_t
- Used for read-write locks.
- pthread_rwlockattr_t
- Used for read-write lock attributes.
- pthread_spinlock_t
- Used to identify a spin lock.
- pthread_t
- Used to identify a thread.
- reclen_t
- Used for directory entry lengths.
- size_t
- Used for sizes of objects.
- ssize_t
- Used for a count of bytes or an error indication.
- suseconds_t
- Used for time in microseconds.
- time_t
- Used for time in seconds.
- timer_t
- Used for timer ID returned by timer_create().
- uid_t
- Used for user IDs.
All of the types shall be defined as arithmetic types of an appropriate length, with the following exceptions:
pthread_attr_t
pthread_barrier_t
pthread_barrierattr_t
pthread_cond_t
pthread_condattr_t
pthread_key_t
pthread_mutex_t
pthread_mutexattr_t
pthread_once_t
pthread_rwlock_t
pthread_rwlockattr_t
pthread_spinlock_t
pthread_t
timer_tAdditionally:
mode_t shall be an integer type.
dev_t shall be an integer type.
nlink_t, uid_t, gid_t, and id_t shall be integer types.
blkcnt_t and off_t shall be signed integer types.
fsblkcnt_t, fsfilcnt_t, reclen_t, and ino_t shall be defined as unsigned integer types.
size_t shall be an unsigned integer type.
blksize_t, pid_t, and ssize_t shall be signed integer types.
clock_t shall be an integer or real-floating type.
[CX]
time_t shall be an integer type with a width (see <stdint.h> ) of at least 64 bits.
The type ssize_t shall be capable of storing values at least in the range [-1, {SSIZE_MAX}].
[XSI]
The type suseconds_t shall be a signed integer type capable of storing values at least in the range [-1, 1000000].
The implementation shall support one or more programming environments in which the widths of blksize_t, pid_t, size_t, ssize_t, and suseconds_t are no greater than the width of type long. The names of these programming environments can be obtained using the confstr() function or the getconf utility.
There are no defined comparison or assignment operators for the following types:
pthread_attr_t
pthread_barrier_t
pthread_barrierattr_t
pthread_cond_t
pthread_condattr_t
pthread_mutex_t
pthread_mutexattr_t
pthread_rwlock_t
pthread_rwlockattr_t
pthread_spinlock_t
timer_t
None.
None.
None.
XSH confstr
XCU getconf
First released in Issue 1. Derived from Issue 1 of the SVID.
The clockid_t and timer_t types are defined for alignment with the POSIX Realtime Extension.
The types blkcnt_t, blksize_t, fsblkcnt_t, fsfilcnt_t, and suseconds_t are added.
Large File System extensions are added.
Updated for alignment with the POSIX Threads Extension.
The pthread_barrier_t, pthread_barrierattr_t, and pthread_spinlock_t types are added for alignment with IEEE Std 1003.1j-2000.
The margin code is changed from XSI to THR for the pthread_rwlock_t and pthread_rwlockattr_t types as Read-Write Locks have been absorbed into the POSIX Threads option. The threads types are marked THR.
IEEE Std 1003.1-2001/Cor 2-2004, item XBD/TC2/D6/26 is applied, adding pthread_t to the list of types that are not required to be arithmetic types, thus allowing pthread_t to be defined as a structure.
Austin Group Interpretation 1003.1-2001 #033 is applied, requiring key_t to be an arithmetic type.
The Trace option types are marked obsolescent.
The clock_t and id_t types are moved from the XSI option to the Base.
The pthread_barrier_t and pthread_barrierattr_t types are moved from the Barriers option to the Base.
The pthread_spinlock_t type is moved from the Spin Locks option to the Base.
Functionality relating to the Timers and Threads options is moved to the Base.
POSIX.1-2008, Technical Corrigendum 1, XBD/TC1-2008/0069 [210], XBD/TC1-2008/0070 [28], XBD/TC1-2008/0071 [376], XBD/TC1-2008/0072 [210], and XBD/TC1-2008/0073 [327] are applied.
POSIX.1-2008, Technical Corrigendum 2, XBD/TC2-2008/0079 [856] and XBD/TC2-2008/0080 [659] are applied.
Austin Group Defect 697 is applied, adding reclen_t.
Austin Group Defect 1330 is applied, removing obsolescent interfaces.
Austin Group Defect 1462 is applied, changing time_t to have a width of at least 64 bits.
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