差異處
這裏顯示兩個版本的差異處。
| Both sides previous revision 前次修改 下次修改 | 前次修改 | ||
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linux:shell_script:execution_time_measurement [2016/07/02 11:12] tony |
linux:shell_script:execution_time_measurement [2023/06/25 09:48] (目前版本) |
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| 行 1: | 行 1: | ||
| + | {{tag>Linux ShellScript}} | ||
| ====== 測量執行時間 ====== | ====== 測量執行時間 ====== | ||
| ===== time command ===== | ===== time command ===== | ||
| 行 22: | 行 23: | ||
| echo $END | echo $END | ||
| + | </code> | ||
| + | ===== date command ===== | ||
| + | 與$SECONDS方法類似，但可以精確到nano second(10^-9)的差距: | ||
| + | <code bash> | ||
| + | START=`date +%s%N` | ||
| + | echo $START | ||
| + | |||
| + | # some operations | ||
| + | sleep 1 | ||
| + | |||
| + | END=`date +%s%N` | ||
| + | echo $END | ||
| + | |||
| + | END=$(($END - $START)) | ||
| + | echo $END | ||
| + | |||
| + | # 換算為millisecond | ||
| + | END=$(($END / 1000000)) | ||
| + | echo $END | ||
| + | </code> | ||
| + | |||
| + | output: | ||
| + | |||
| + | <code bash> | ||
| + | 1467450293336690574 | ||
| + | 1467450294338625297 | ||
| + | 1001934723 | ||
| + | 1001 | ||
| </code> | </code> | ||
| ===== Reference ===== | ===== Reference ===== | ||
| * [[http://www.livefirelabs.com/unix_tip_trick_shell_script/oct_2003/10272003.htm|Useful Shell Script Variables - Part V - SECONDS]] | * [[http://www.livefirelabs.com/unix_tip_trick_shell_script/oct_2003/10272003.htm|Useful Shell Script Variables - Part V - SECONDS]] | ||
| + | * [[http://stackoverflow.com/questions/16548528/linux-command-to-get-time-in-milliseconds#comment57307577_16548528|Linux command to get time in milliseconds]] | ||
| ===== ===== | ===== ===== | ||
