xref: /freebsd/usr.bin/time/time.1 (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
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32.\"     @(#)time.1	8.1 (Berkeley) 6/6/93
33.\"
34.Dd June 6, 1993
35.Dt TIME 1
36.Os BSD 4
37.Sh NAME
38.Nm time
39.Nd time command execution
40.Sh SYNOPSIS
41.Nm
42.Op Fl alp
43.Op Fl o Ar file
44.Ar command
45.Sh DESCRIPTION
46The
47.Nm
48utility
49executes and
50times
51.Ar command
52by initiating a timer and passing the
53.Ar command
54to the
55shell.
56After the
57.Ar command
58finishes,
59.Nm
60writes to the standard error stream,
61(in seconds):
62the total time elapsed,
63the time used to execute the
64.Ar command
65process and the time consumed by system overhead.
66.Pp
67Available options:
68.Bl -tag -width Ds
69.It Fl a
70If the
71.Fl o
72flag is used, append to the specified file rather than overwriting
73it. Otherwise, this option has no effect.
74.It Fl l
75The contents of the
76.Em rusage
77structure are printed as well.
78.It Fl o Ar file
79Write the output to
80.Ar file
81instead of stderr.  If
82.Ar file
83exists and the
84.Fl a
85flag is not specified, the file will be overwritten.
86.It Fl p
87Makes
88.Nm
89output POSIX.2 compliant (each time is printed on its own line).
90.El
91.Pp
92Most shells (including
93.Xr csh 1 )
94have their own and syntactically different builtin version of
95.Nm time .
96The command described here
97is available as
98.Pa /usr/bin/time
99to users of those shells.
100.Sh DIAGNOSTICS
101If
102.Ar command
103could be timed successfully, its exit status is returned. In case
104.Ar command
105terminated abnormally, a warning message is output to stderr.
106If the
107.Ar command
108was found but could not be run, the exit status is 126.
109If no
110.Ar command
111could be found at all, the exit status is 127.
112If
113.Nm
114encounters any other error, the exit status is between 1 and 125
115included.
116.Sh SEE ALSO
117.Xr csh 1 ,
118.Xr getrusage 2 ,
119.Xr wait 2
120.Sh STANDARDS
121The
122.Nm
123utility is expected to conform to ISO/IEC 9945-2:1993 (``POSIX'').
124.Sh HISTORY
125A
126.Nm
127command appeared in
128.At v6 .
129