system_data_types(7)

1SYSTEM_DATA_TYPES(7)       Linux Programmer's Manual      SYSTEM_DATA_TYPES(7)
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NAME

6       system_data_types - overview of system data types
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DESCRIPTION

9       aiocb
10              Include: <aio.h>.
11
12              struct aiocb {
13                  int             aio_fildes;    /* File descriptor */
14                  off_t           aio_offset;    /* File offset */
15                  volatile void  *aio_buf;       /* Location of buffer */
16                  size_t          aio_nbytes;    /* Length of transfer */
17                  int             aio_reqprio;   /* Request priority offset */
18                  struct sigevent aio_sigevent;  /* Signal number and value */
19                  int             aio_lio_opcode;/* Operation to be performed */
20              };
21
22              For further information about this structure, see aio(7).
23
24              Conforming to: POSIX.1-2001 and later.
25
26              See    also:    aio_cancel(3),    aio_error(3),    aio_fsync(3),
27              aio_read(3),   aio_return(3),   aio_suspend(3),    aio_write(3),
28              lio_listio(3)
29
30       blkcnt_t
31              Include: <sys/types.h>.  Alternatively, <sys/stat.h>.
32
33              Used  for  file block counts.  According to POSIX, it shall be a
34              signed integer type.
35
36              Conforming to: POSIX.1-2001 and later.
37
38              See also: stat(2)
39
40       blksize_t
41              Include: <sys/types.h>.  Alternatively, <sys/stat.h>.
42
43              Used for file block sizes.  According to POSIX, it  shall  be  a
44              signed integer type.
45
46              Conforming to: POSIX.1-2001 and later.
47
48              See also: stat(2)
49
50       cc_t
51              Include: <termios.h>.
52
53              Used  for  terminal  special characters.  According to POSIX, it
54              shall be an unsigned integer type.
55
56              Conforming to: POSIX.1-2001 and later.
57
58              See also: termios(3)
59
60       clock_t
61              Include:    <time.h>    or    <sys/types.h>.      Alternatively,
62              <sys/time.h>.
63
64              Used  for  system time in clock ticks or CLOCKS_PER_SEC (defined
65              in <time.h>).  According to POSIX, it shall be an  integer  type
66              or a real-floating type.
67
68              Conforming to: C99 and later; POSIX.1-2001 and later.
69
70              See also: times(2), clock(3)
71
72       clockid_t
73              Include: <sys/types.h>.  Alternatively, <time.h>.
74
75              Used  for  clock  ID type in the clock and timer functions.  Ac‐
76              cording to POSIX, it shall be defined as an arithmetic type.
77
78              Conforming to: POSIX.1-2001 and later.
79
80              See also: clock_adjtime(2), clock_getres(2), clock_nanosleep(2),
81              timer_create(2), clock_getcpuclockid(3)
82
83       dev_t
84              Include: <sys/types.h>.  Alternatively, <sys/stat.h>.
85
86              Used for device IDs.  According to POSIX, it shall be an integer
87              type.  For further details of this type, see makedev(3).
88
89              Conforming to: POSIX.1-2001 and later.
90
91              See also: mknod(2), stat(2)
92
93       div_t
94              Include: <stdlib.h>.
95
96              typedef struct {
97                  int quot; /* Quotient */
98                  int rem;  /* Remainder */
99              } div_t;
100
101              It is the type of the value returned by the div(3) function.
102
103              Conforming to: C99 and later; POSIX.1-2001 and later.
104
105              See also: div(3)
106
107       double_t
108              Include: <math.h>.
109
110              The implementation's most efficient floating type  at  least  as
111              wide  as  double.   Its  type  depends on the value of the macro
112              FLT_EVAL_METHOD (defined in <float.h>):
113
114              0      double_t is double.
115
116              1      double_t is double.
117
118              2      double_t is long double.
119
120              For other values of FLT_EVAL_METHOD, the type of double_t is im‐
121              plementation-defined.
122
123              Conforming to: C99 and later; POSIX.1-2001 and later.
124
125              See also: the float_t type in this page.
126
127       fd_set
128              Include: <sys/select.h>.  Alternatively, <sys/time.h>.
129
130              A  structure  type that can represent a set of file descriptors.
131              According to POSIX, the maximum number of file descriptors in an
132              fd_set structure is the value of the macro FD_SETSIZE.
133
134              Conforming to: POSIX.1-2001 and later.
135
136              See also: select(2)
137
138       fenv_t
139              Include: <fenv.h>.
140
141              This  type represents the entire floating-point environment, in‐
142              cluding control modes and status flags; for further details, see
143              fenv(3).
144
145              Conforming to: C99 and later; POSIX.1-2001 and later.
146
147              See also: fenv(3)
148
149       fexcept_t
150              Include: <fenv.h>.
151
152              This  type  represents  the  floating-point status flags collec‐
153              tively; for further details see fenv(3).
154
155              Conforming to: C99 and later; POSIX.1-2001 and later.
156
157              See also: fenv(3)
158
159       FILE
160              Include: <stdio.h>.  Alternatively, <wchar.h>.
161
162              An object type used for streams.
163
164              Conforming to: C99 and later; POSIX.1-2001 and later.
165
166              See  also:  fclose(3),   flockfile(3),   fopen(3),   fprintf(3),
167              fread(3), fscanf(3), stdin(3), stdio(3)
168
169       float_t
170              Include: <math.h>.
171
172              The  implementation's  most  efficient floating type at least as
173              wide as float.  Its type depends  on  the  value  of  the  macro
174              FLT_EVAL_METHOD (defined in <float.h>):
175
176              0      float_t is float.
177
178              1      float_t is double.
179
180              2      float_t is long double.
181
182              For  other values of FLT_EVAL_METHOD, the type of float_t is im‐
183              plementation-defined.
184
185              Conforming to: C99 and later; POSIX.1-2001 and later.
186
187              See also: the double_t type in this page.
188
189       gid_t
190              Include: <sys/types.h>.  Alternatively, <grp.h>, <pwd.h>,  <sig‐