Linux 的 date 指令可以輸出目前的日期及時間, 例如直接輸入 date 指令, 會輸出很詳細的日期及時間:
$ date
Fri Mar 10 09:15:51 HKT 2017
Fri Mar 10 09:15:51 HKT 2017
而 date 指令除了預設的格式外, 也可以自訂日期格式, 語法是 date +”FORMAT”, 例如我想顯示 DD-MM-YYYY 格式的日期, 可以這樣做:
1 2 |
$ date +"%d-%m-%Y" 10-03-2017 |
這樣自訂日期時間格式在 Shell Script 很常用, 用 date 指令可以將現在的日期放到 Shell Script 的變數, 例如:
1 2 3 4 5 |
#!/bin/bash TODAY=$(date +"%d-%m-%Y") echo $TODAY |
除了上面的用法外, date 完整的日期時間代號如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 |
%% a literal % %a locale’s abbreviated weekday name (e.g., Sun) %A locale’s full weekday name (e.g., Sunday) %b locale’s abbreviated month name (e.g., Jan) %B locale’s full month name (e.g., January) %c locale’s date and time (e.g., Thu Mar 3 23:05:25 2005) %C century; like %Y, except omit last two digits (e.g., 20) %d day of month (e.g, 01) %D date; same as %m/%d/%y %e day of month, space padded; same as %_d %F full date; same as %Y-%m-%d %g last two digits of year of ISO week number (see %G) %G year of ISO week number (see %V); normally useful only with %V %h same as %b %H hour (00..23) %I hour (01..12) %j day of year (001..366) %k hour ( 0..23) %l hour ( 1..12) %m month (01..12) %M minute (00..59) %n a newline %N nanoseconds (000000000..999999999) %p locale’s equivalent of either AM or PM; blank if not known %P like %p, but lower case %r locale’s 12-hour clock time (e.g., 11:11:04 PM) %R 24-hour hour and minute; same as %H:%M %s seconds since 1970-01-01 00:00:00 UTC %S second (00..60) %t a tab %T time; same as %H:%M:%S %u day of week (1..7); 1 is Monday %U week number of year, with Sunday as first day of week (00..53) %V ISO week number, with Monday as first day of week (01..53) %w day of week (0..6); 0 is Sunday %W week number of year, with Monday as first day of week (00..53) %x locale’s date representation (e.g., 12/31/99) %X locale’s time representation (e.g., 23:13:48) %y last two digits of year (00..99) %Y year %z +hhmm numeric timezone (e.g., -0400) %:z +hh:mm numeric timezone (e.g., -04:00) %::z +hh:mm:ss numeric time zone (e.g., -04:00:00) %:::z numeric time zone with : to necessary precision (e.g., -04, +05:30) %Z alphabetic time zone abbreviation (e.g., EDT) By default, date pads numeric fields with zeroes. The following optional flags may follow ‘%’: - (hyphen) do not pad the field _ (underscore) pad with spaces 0 (zero) pad with zeros ^ use upper case if possible # use opposite case if possible |