xref: /netbsd-src/usr.bin/time/time.1 (revision c2f76ff004a2cb67efe5b12d97bd3ef7fe89e18d)
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30.\"     @(#)time.1	8.1 (Berkeley) 6/6/93
31.\"
32.Dd May 16, 2010
33.Dt TIME 1
34.Os
35.Sh NAME
36.Nm time
37.Nd time command execution
38.Sh SYNOPSIS
39.Nm
40.Op Fl clp
41.Ar utility
42.Op Ar argument ...
43.Sh DESCRIPTION
44The
45.Nm
46utility
47executes and
48times
49.Ar utility .
50After the
51.Ar utility
52finishes,
53.Nm
54writes the total time elapsed,
55the time consumed by system overhead,
56and the time used to execute
57.Ar utility
58to the standard error stream.
59Times are reported in seconds.
60.Pp
61Available options:
62.Bl -tag -width Ds
63.It Fl c
64Displays information in the format used by the
65.Nm
66builtin of
67.Xr csh 1 .
68.It Fl l
69Lists resource utilization information.
70The contents of the
71.Ar utility
72process'
73.Em rusage
74structure are printed; see below.
75.It Fl p
76The output is formatted as specified by
77.St -p1003.2-92 .
78.El
79.Pp
80Some shells, such as
81.Xr csh 1
82and
83.Xr ksh 1 ,
84have their own and syntactically different builtin version of
85.Nm .
86The utility described here
87is available as
88.Pa /usr/bin/time
89to users of these shells.
90.Ss Resource Utilization
91If the
92.Fl l
93option is given, the following resource usage
94information is displayed
95in addition to the timing information:
96.Bl -item -offset indent -compact
97.It
98maximum resident set size
99.It
100average shared memory size
101.It
102average unshared data size
103.It
104average unshared stack size
105.It
106page reclaims
107.It
108page faults
109.It
110swaps
111.It
112block input operations
113.It
114block output operations
115.It
116messages sent
117.It
118messages received
119.It
120signals received
121.It
122voluntary context switches
123.It
124involuntary context switches
125.El
126Resource usage is the total for the execution of
127.Ar utility
128and any child processes it spawns, as per
129.Xr wait4 2 .
130.Sh EXIT STATUS
131The
132.Nm
133utility exits with one of the following values:
134.Bl -tag -width indent
135.It 1-125
136An error occurred in the
137.Nm
138utility.
139.It 126
140The
141.Ar utility
142was found but could not be invoked.
143.It 127
144The
145.Ar utility
146could not be found.
147.El
148.Pp
149Otherwise, the exit status of
150.Nm
151will be that of
152.Ar utility .
153.Sh FILES
154.Bl -tag -width \*[Lt]sys/resource.h\*[Gt] -compact
155.It \*[Lt]sys/resource.h\*[Gt]
156.El
157.Sh SEE ALSO
158.Xr csh 1 ,
159.Xr ksh 1 ,
160.Xr getrusage 2
161.Sh STANDARDS
162The
163.Nm
164utility conforms to
165.St -p1003.2-92 .
166.Sh BUGS
167The granularity of seconds on microprocessors is crude and
168can result in times being reported for CPU usage which are too large by
169a second.
170