time=$(date -u +%j%H%M%S)
时间: 2024-04-16 15:26:01 浏览: 33
这行代码是在脚本中使用 `date` 命令获取当前日期和时间,并将其格式化为 `%j%H%M%S` 的形式,然后将结果赋值给变量 `time`。
具体解释如下:
- `date -u`:使用协调世界时(UTC)来获取当前日期和时间。
- `+%j%H%M%S`:这是 `date` 命令中的格式选项,它指定了输出的日期和时间的格式。具体含义如下:
- `%j`:表示一年中的第几天,范围是 001 到 366。
- `%H`:表示小时,范围是 00 到 23。
- `%M`:表示分钟,范围是 00 到 59。
- `%S`:表示秒,范围是 00 到 59。
因此,这行代码的作用是将当前日期和时间按照 `%j%H%M%S` 的格式格式化,并将结果赋值给变量 `time`。
相关问题
date --help
`date --help`命令用于显示Linux系统上`date`命令的帮助信息和可用选项。以下是`date --help`命令的输出:
```
Usage: date [OPTION]... [+FORMAT]
or: date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
Display the current time in the given FORMAT, or set the system date.
Formatting:
%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, space padded ( 0..23); same as %_H
%l hour, space padded ( 1..12); same as %_I
%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 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
After any flags comes an optional field width, as a decimal number; then
an optional modifier, which is either E to use the locale's alternate
representations if available, or O to use the locale's alternate numeric
symbols if available.
```
该命令列出了`date`命令支持的所有选项和格式化选项,可以帮助您更好地了解如何使用该命令。
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