freebsd-src/usr.bin/time/time.1
Dag-Erling Smørgrav 28f5cafe82 Behave like GNU time. More cleanup. Reword man page.
Pointed out by:	Bruce Evans
1998-07-27 16:54:05 +00:00

131 lines
3.3 KiB
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.\" @(#)time.1 8.1 (Berkeley) 6/6/93
.\"
.Dd June 6, 1993
.Dt TIME 1
.Os BSD 4
.Sh NAME
.Nm time
.Nd time command execution
.Sh SYNOPSIS
.Nm
.Op Fl l
.Op Fl a
.Op Fl o Ar file
.Ar command
.Sh DESCRIPTION
The
.Nm
utility
executes and
times
.Ar command
by initiating a timer and passing the
.Ar command
to the
shell.
After the
.Ar command
finishes,
.Nm
writes to the standard error stream,
(in seconds):
the total time elapsed,
time consumed by system overhead,
and the time used to execute the
.Ar command
process.
.Pp
Available options:
.Bl -tag -width Ds
.It Fl l
The contents of the
.Em rusage
structure are printed as well.
.It Fl a
If the
.Fl o
flag is used, append to the specified file rather than overwriting
it. Otherwise, this option has no effect.
.It Fl o Ar file
Write the output to
.Ar file
instead of stderr. If
.Ar file
exists and the
.Fl a
flag is not specified, the file will be overwritten.
.El
.Sh NOTES
.Pp
The
.Xr csh 1
has its own and syntactically different builtin version of
.Nm time .
The command described here
is available as
.Pa /usr/bin/time
to
.Xr csh
users.
The output of
.Nm
can be directed to standard output by specifying
.Do
-
.Dc
as the argument to the
.Fl a
or
.Fl o
option.
.Pp
The
.Fl a
and
.Fl o
options are mutually exclusive.
.Sh BUGS
The granularity of seconds on micro processors is crude and
can result in times being reported for CPU usage which are too large by
a second.
.Sh SEE ALSO
.Xr csh 1 ,
.Xr getrusage 2 ,
.Xr wait 2
.Sh HISTORY
A
.Nm
command appeared in
.At v6 .