xref: /freebsd/lib/libc/gen/times.3 (revision 076b94438c7d42c1b4661ed1e12e3b12ca69361a)
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28.\"     @(#)times.3	8.1 (Berkeley) 6/4/93
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31.Dd December 1, 2008
32.Dt TIMES 3
33.Os
34.Sh NAME
35.Nm times
36.Nd process times
37.Sh LIBRARY
38.Lb libc
39.Sh SYNOPSIS
40.In sys/times.h
41.Ft clock_t
42.Fn times "struct tms *tp"
43.Sh DESCRIPTION
44.Bf -symbolic
45This interface is obsoleted by
46.Xr getrusage 2
47and
48.Xr gettimeofday 2 .
49.Ef
50.Pp
51The
52.Fn times
53function returns the value of time in
54.Dv CLK_TCK Ns 's
55of a second since the system startup time.
56The current value of
57.Dv CLK_TCK ,
58the frequency of the statistics clock in ticks per second, may be
59obtained through the
60.Xr sysconf 3
61interface.
62.Pp
63It also fills in the structure pointed to by
64.Fa tp
65with time-accounting information.
66.Pp
67The
68.Vt tms
69structure is defined as follows:
70.Bd -literal -offset indent
71struct tms {
72	clock_t tms_utime;
73	clock_t tms_stime;
74	clock_t tms_cutime;
75	clock_t tms_cstime;
76};
77.Ed
78.Pp
79The elements of this structure are defined as follows:
80.Bl -tag -width ".Va tms_cutime"
81.It Va tms_utime
82The
83.Tn CPU
84time charged for the execution of user instructions.
85.It Va tms_stime
86The
87.Tn CPU
88time charged for execution by the system on behalf of
89the process.
90.It Va tms_cutime
91The sum of the
92.Va tms_utime Ns s
93and
94.Va tms_cutime Ns s
95of the child processes.
96.It Va tms_cstime
97The sum of the
98.Fa tms_stime Ns s
99and
100.Fa tms_cstime Ns s
101of the child processes.
102.El
103.Pp
104All times are in
105.Dv CLK_TCK Ns 's
106of a second.
107.Pp
108The times of a terminated child process are included in the
109.Va tms_cutime
110and
111.Va tms_cstime
112elements of the parent when one of the
113.Xr wait 2
114functions returns the process ID of the terminated child to the parent.
115If an error occurs,
116.Fn times
117returns the value
118.Pq Po Vt clock_t Pc Ns \-1 ,
119and sets
120.Va errno
121to indicate the error.
122.Sh ERRORS
123The
124.Fn times
125function
126may fail and set the global variable
127.Va errno
128for any of the errors specified for the library
129routines
130.Xr getrusage 2
131and
132.Xr gettimeofday 2 .
133.Sh SEE ALSO
134.Xr time 1 ,
135.Xr getrusage 2 ,
136.Xr gettimeofday 2 ,
137.Xr wait 2 ,
138.Xr sysconf 3 ,
139.Xr clocks 7
140.Sh STANDARDS
141The
142.Fn times
143function
144conforms to
145.St -p1003.1-88 .
146