Linux time命令

#help time
time: time [-p] pipeline
    Report time consumed by pipeline's execution.
    
    Execute PIPELINE and print a summary of the real time, user CPU time,
    and system CPU time spent executing PIPELINE when it terminates.
    
    Options:
      -p	print the timing summary in the portable Posix format
    
    The value of the TIMEFORMAT variable is used as the output format.
    
    Exit Status:
    The return status is the return status of PIPELINE.
times: times
    Display process times.
    
    Prints the accumulated user and system times for the shell and all of its
    child processes.
    
    Exit Status:
    Always succeeds.

#time date
Wed Sep 29 02:00:29 CST 2021

real	0m0.002s
user	0m0.001s
sys	    0m0.001s

• time