January 24, 2009 TIME 1

### 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.