types (0p) - Linux Manuals
types: data types
NAME
sys/types.h - data types
SYNOPSIS
DESCRIPTION
The <sys/types.h> header shall include definitions for 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
- 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.
- 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().
- trace_attr_t
- Used to identify a trace stream attributes object.
- trace_event_id_t
- Used to identify a trace event type.
- trace_event_set_t
- Used to identify a trace event type set.
- trace_id_t
- Used to identify a trace stream.
- uid_t
- Used for user IDs.
- useconds_t
-
Used for time in microseconds.
All of the types shall be defined as arithmetic types of an appropriate length, with the following exceptions:
key_t
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
trace_attr_t
trace_event_id_t
trace_event_set_t
trace_id_t
Additionally:
- *
- mode_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, 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.
- *
- time_t and clock_t shall be integer or real-floating types.
The type ssize_t shall be capable of storing values at least
in the range [-1,
The implementation shall support one or more programming environments
in which the widths of blksize_t, pid_t,
size_t, ssize_t, suseconds_t, and useconds_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_cond_t
pthread_spinlock_t
trace_attr_t
The following sections are informative.
<time.h>, the System Interfaces volume of IEEE Std 1003.1-2001,
confstr(), the Shell and Utilities volume of IEEE Std 1003.1-2001,
getconf
pthread_barrierattr_t
pthread_condattr_t
pthread_mutex_t
pthread_mutexattr_t
pthread_rwlock_t
pthread_rwlockattr_t
APPLICATION USAGE
RATIONALE
FUTURE DIRECTIONS
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
SEE ALSO