<sys/types.h>(0P)                                   POSIX Programmer's Manual                                  <sys/types.h>(0P)



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  environ-
       ments 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, Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                             <sys/types.h>(0P)