NAME

       sys/types.h - data types

SYNOPSIS

       #include <sys/types.h>

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, {SSIZE_MAX}].    The type useconds_t shall be an unsigned  integer  type  capable  of
       storing  values at least in the range [0, 1000000]. 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, 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_barrierattr_t

       pthread_cond_t
       pthread_condattr_t
       pthread_mutex_t
       pthread_mutexattr_t
       pthread_rwlock_t
       pthread_rwlockattr_t

       pthread_spinlock_t

       trace_attr_t

       The following sections are informative.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       <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

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 .