types(5)

types -- primitive system data types

Synopsis

   #include <sys/types.h>

Description

The data types defined in types.h are used in UNIX system code. Some data of these types are accessible to user code. The typedef name should be used where appropriate since the binding to underlying types is subject to change.

   typedef struct { int r[1]; }        physadr;
   typedef signed                       blkcnt_t        +
   typedef long                        clock_t;
   typedef long                        daddr_t;
   typedef char                       caddr_t;
   typedef unsigned                     fsblkcnt_t;      +
   typedef unsigned                     fsfilcnt_t;      +
   typedef unsigned char               uchar_t;
   typedef unsigned short              ushort_t;
   typedef unsigned int                uint_t;
   typedef unsigned long               ulong_t;
   typedef unsigned long               llong_t;
   typedef unsigned long               ullong_t;
   typedef unsigned                     ino_t;            +
   typedef long                        uid_t;
   typedef long                        gid_t;
   typedef unsigned long               nlink_t;
   typedef unsigned long               mode_t;
   typedef short                       cnt_t;
   typedef long                        time_t;
   typedef int                         label_t[10];
   typedef unsigned long               dev_t;
   typedef signed                       off_t;            +
   typedef unsigned                     uoff_t;           +
   typedef long                        pid_t;
   typedef unsigned long               paddr_t;
   typedef int                         key_t;
   typedef unsigned char               use_t;
   typedef short                       sysid_t;
   typedef short                       index_t;
   typedef short                       lock_t;
   typedef unsigned int                size_t;
   typedef int                         ssize_t;

+: This data type is a 32 bit/64 bit switchable data type. See ``Large File Support'' on intro(2) for information on Large File Support (LFS).

The form daddr_t is used for disk addresses except in an i-node on disk, see, for example, fs_s5(4). Times are encoded in seconds since 00:00:00 UTC, January 1, 1970. The major and minor parts of a device code specify kind and unit number of a device and are installation-dependent. Offsets are measured in bytes from the beginning of a file. The label_t variables are used to save the processor state while another process is running.