NAME
time
- time command execution
SYNOPSIS
time
[-clp]
utility
[argument ...]
DESCRIPTION
The
time
utility
executes and
times
utility.
After the
utility
finishes,
time
writes the total time elapsed,
the time consumed by system overhead,
and the time used to execute
utility
to the standard error stream.
Times are reported in seconds.
Available options:
- -c
-
Displays the default
csh(1)
summary format.
- -l
-
Lists resource utilization information.
The contents of the
utility
process'
rusage
structure are printed, see below.
- -p
-
The output is formatted as specified by
IEEE Std 1003.2-1992 (``POSIX.2'') .
Some shells, such as
csh(1)
and
ksh(1),
have their own and syntactically different builtin version of
.
The utility described here
is available as
/usr/bin/time
to users of these shells.
Resource Utilization
If the
-l
option is given, the following resource usage
informations are displayed
in addition to the timing information:
-
maximum resident set size
-
average shared memory size
-
average unshared data size
-
average unshared stack size
-
page reclaims
-
page faults
-
swaps
-
block input operations
-
block output operations
-
messages sent
-
messages received
-
signals received
-
voluntary context switches
-
involuntary context switches
EXIT STATUS
The
time
utility exits with one of the following values:
- 1-125
-
An error occurred in the
time
utility.
- 126
-
The
utility
was found but could not be invoked.
- 127
-
The
utility
could not be found.
Otherwise, the exit status of
time
will be that of
utility.
FILES
- <sys/resource.h>
-
SEE ALSO
csh(1),
ksh(1),
getrusage(2)
STANDARDS
The
time
utility conforms to
IEEE Std 1003.2-1992 (``POSIX.2'') .
BUGS
The granularity of seconds on microprocessors is crude and
can result in times being reported for CPU usage which are too large by
a second.