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echo $(( $(date +%s) - $(date -r FILE +%s) ))
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ã³ãã³ãã®ãç´°ããã¨ãããä¸ã¤ãã¤è¦ã¦ããã¾ãã
date ã³ãã³ãã§intç§æ°ã表示ãã
ã¾ã㯠date ã³ãã³ãã§ç§æ°ãåºãæ¹æ³ãããã¯ç¾å¨ã®unix ç§ãåºã¾ãã
date +%s
date ã³ãã³ãã§ãã¡ã¤ã«ã®æ´æ°æ¥ä»ãåå¾ãã
次ã«ããã¡ã¤ã«ã®æ´æ°æå»ã date ã®å¼æ°ã¨ãã¦æå®ãã¦ãããã
date -r FILE
çµã¿åããã¦ãdate ã³ãã³ãã§ãã¡ã¤ã«ã®ä½ææãintç§ã§è¡¨ç¤ºãã
date -r FILE +%s
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unix ç§ãåãã ãªãããããæ¯è¼ã®ããã«å¼ãç®ãã¦ä¸ããå¿ è¦ãããã¾ãã
echo $(( 100 -1 ))
ãããããã¹ã¦çµã¿åããã
ãã¡ã¤ã«ãä½ããã¦ããä½ç§ï¼ä½æéï¼çµéãã¦ããããè¨ç®ã§ãã
echo $(( $(date +%s) - $(date -r FILE +%s) ))
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ãã¡ã¤ã«ã使ããã¦ãã1000ç§çµéãã¦ããåèµ·åãããããªæ¡ä»¶åå²ã«ä½¿ããã¨ãåºæ¥ã¾ãã
(( $(( $(date +%s) - $(date -r FILE +%s) )) > 1000 )) && restart-server
ãã¡ã¤ã«A/Bã§Aã®ã»ããå¤ããã°ãªã«ãããã
(( $(( $(date +%s -r FILEA ) - $(date -r FILEB +%s) )) < 0 )) && echo old
è¨å· $( ( expr )) ã ( ( expr )) ãªã©ã®bash ã®è¨å·ã«ã¤ãã¦ã¯
Bashã®è¨å·ã«ã¤ãã¦ã¯ãéå»è¨äºãåèã«ãã¦ãã ãã
- bashのif文で数字の比較を評価条件ぱぱっとやる方法(C言語スタイル - それマグで!
- bashの似てて紛らわしいもの [[ / (( - それマグで!
- bashの似てて紛らわしいもの (( / $(( - それマグで!
åèè³æ
man bash