NAME
time —
time command execution
SYNOPSIS
time |
[-al] [-h |
-p] [-o
file] utility
[argument ...] |
DESCRIPTION
Thetime utility executes and times the specified
utility. After the utility
finishes, time writes to the standard error stream,
(in seconds): the total time elapsed, the time used to execute the
utility process and the time consumed by system
overhead.
The following options are available:
-a- If the
-oflag is used, append to the specified file rather than overwriting it. Otherwise, this option has no effect. -h- Print times in a human friendly format. Times are printed in minutes, hours, etc. as appropriate.
-l- The contents of the rusage structure are printed as well.
-ofile- Write the output to file instead of stderr. If
file exists and the
-aflag is not specified, the file will be overwritten. -p- Makes
timeoutput POSIX.2 compliant (each time is printed on its own line).
Some shells may provide a builtin time
command which is similar or identical to this utility. Consult the
builtin(1) manual page.
If time receives a
SIGINFO (see the status argument for
stty(1)) signal, the current time the given command is running will
be written to the standard output.
ENVIRONMENT
The PATH environment variable is used to
locate the requested utility if the name contains no
‘/’ characters.
EXIT STATUS
If utility could be timed successfully, its
exit status is returned. If the utility was found but
could not be run, the exit status is 126. If no
utility could be found at all, the exit status is 127.
If time encounters any other error, the exit status
is between 1 and 125 included.
DIAGNOSTICS
If utility terminated abnormally, a warning message is output to stderr.
SEE ALSO
STANDARDS
The time utility is expected to conform to
ISO/IEC 9945-2:1993 (``POSIX'').
HISTORY
A time utility appeared in
Version 3 AT&T UNIX.