time echo - Githubissues

leo424y commented 6 years ago

發現

time 再加command 取得執行時間，取消時也能得到花費時間real/user/sys https://unix.stackexchange.com/questions/52313/how-to-get-execution-time-of-a-script-effectively

time cat, time ls 都有, 但 time echo 沒有印時間是為太短嗎？

TIME(1)                   BSD General Commands Manual                  TIME(1)

NAME
     time -- time command execution

SYNOPSIS
     time [-lp] utility

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:

     -l      The contents of the rusage structure are printed.

     -p      The output is formatted as specified by IEEE Std 1003.2-1992 (``POSIX.2'').

     Some shells may provide a builtin time command which is similar or identical to this utility.  Consult
     the builtin(1) manual page.

DIAGNOSTICS
     The time utility shall exit 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 shall be that of utility.

SEE ALSO
     builtin(1), csh(1), getrusage(2)

FILES
     /usr/include/sys/resource.h

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.

BSD                              June 6, 1993                              BSD

sih4sing5hong5 commented 6 years ago

我有--neh

$ time echo

real    0m0.000s
user    0m0.000s
sys 0m0.000s

leo424y commented 6 years ago

酷！果然是快到全都0，我的mac沒有得看。

sih4sing5hong5 commented 6 years ago

我mac嘛有--呢

leo424y commented 6 years ago

我的mac怪怪的！抖

twgo / siann1-hak8_boo5-hing5

time echo #23