xref: /freebsd/usr.bin/time/time.1 (revision 7f3dea244c40159a41ab22da77a434d7c5b5e85a)
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32.\"     @(#)time.1	8.1 (Berkeley) 6/6/93
33.\"     $Id$
34.\"
35.Dd June 6, 1993
36.Dt TIME 1
37.Os BSD 4
38.Sh NAME
39.Nm time
40.Nd time command execution
41.Sh SYNOPSIS
42.Nm
43.Op Fl alp
44.Op Fl o Ar file
45.Ar command
46.Sh DESCRIPTION
47The
48.Nm
49utility
50executes and
51times
52.Ar command
53by initiating a timer and passing the
54.Ar command
55to the
56shell.
57After the
58.Ar command
59finishes,
60.Nm
61writes to the standard error stream,
62(in seconds):
63the total time elapsed,
64the time used to execute the
65.Ar command
66process and the time consumed by system overhead.
67.Pp
68Available options:
69.Bl -tag -width Ds
70.It Fl a
71If the
72.Fl o
73flag is used, append to the specified file rather than overwriting
74it. Otherwise, this option has no effect.
75.It Fl l
76The contents of the
77.Em rusage
78structure are printed as well.
79.It Fl o Ar file
80Write the output to
81.Ar file
82instead of stderr.  If
83.Ar file
84exists and the
85.Fl a
86flag is not specified, the file will be overwritten.
87.It Fl p
88Makes
89.Nm
90output POSIX.2 compliant (each time is printed on its own line).
91.El
92.Pp
93Most shells (including
94.Xr csh 1 )
95have their own and syntactically different builtin version of
96.Nm time .
97The command described here
98is available as
99.Pa /usr/bin/time
100to users of those shells.
101.Sh DIAGNOSTICS
102If
103.Ar command
104could be timed successfully, its exit status is returned. In case
105.Ar command
106terminated abnormally, a warning message is output to stderr.
107If the
108.Ar command
109was found but could not be run, the exit status is 126.
110If no
111.Ar command
112could be found at all, the exit status is 127.
113If
114.Nm
115encounters any other error, the exit status is between 1 and 125
116included.
117.Sh SEE ALSO
118.Xr csh 1 ,
119.Xr getrusage 2 ,
120.Xr wait 2
121.Sh STANDARDS
122The
123.Nm
124utility is expected to conform to ISO/IEC 9945-2:1993 (``POSIX'').
125.Sh HISTORY
126A
127.Nm
128command appeared in
129.At v6 .
130