TIME(1)

NAME
time - time a command

SYNOPSIS
time [ command ]

DESCRIPTION
There are two distinct versions of time: it is built in to the C-shell, and is an executable program available in /bin/time when using the Bourne shell. In both cases, times are displayed on the diagnostic output stream.

In the case of the C-shell, a time command with no command argument simply displays a summary of time used by this shell and its children. When arguments are given the specified simple command is timed and the C-shell displays a time summary as described in csh(1).

The time command in `/bin/time' times the given command, which must be specified, that is, command is not optional as it is in the C-shell's timing facility. When the command is complete, time displays the elapsed time during the command, the time spent in the system, and the time spent in execution of the command. Times are reported in seconds.

EXAMPLES

The two examples here show the differences between the csh version of time and the version in /bin/time. The example assumes that csh is the shell in use.
    angel% time wc /usr/man/man1/csh.1
        1876   11223   65895 /usr/man/man1/csh.1
    2.7u 0.9s 0:03 91% 3+5k 19+2io 1pf+0w
    angel% /bin/time wc /usr/man/man1/csh.1
        1876   11223   65895 /usr/man/man1/csh.1
            4.3 real         2.7 user         1.0 sys
    angel%

SEE ALSO

csh(1)

BUGS
Elapsed time is accurate to the second, while the CPU times are measured to the 50th second. Thus the sum of the CPU times can be up to a second larger than the elapsed time.