TIME(1) General Commands Manual TIME(1)
NAME
timetime 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 information in the format used by the time builtin of csh(1).
-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 time. 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 information is 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
Resource usage is the total for the execution of utility and any child processes it spawns, as per wait4(2).
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
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.