0p:types.h

From Linux Man Pages

      sys/types.h - data types
      
      #include <sys/types.h>

Contents 1 DESCRIPTION 2 APPLICATION USAGE 3 RATIONALE 4 FUTURE DIRECTIONS 5 RELATED 6 COPYRIGHT 7 CATEGORY

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 usec-
      onds_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  pro-
      gramming 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.

RELATED

      <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,  Stan-
      dard  for  Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifica-
      tions 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 .

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

CATEGORY