1. 显示日期命令：date [OPTION]… [+FORMAT]
root@ubuntu:/# date
Sat Sep 8 00:11:09 PDT 2018
#加上date参数,%Y表示4位年，%y表示2位年，%m表示月，%d表示天，更多的参数可通过date --help查看
root@ubuntu:/# date +%Y-%m-%d
2018-09-08
#date的参数如下
root@ubuntu:/# date --h
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.
Mandatory arguments to long options are mandatory for short options too.
-d, --date=STRING display time described by STRING, not 'now'
-f, --file=DATEFILE like --date; once for each line of DATEFILE
-I[FMT], --iso-8601[=FMT] output date/time in ISO 8601 format.
FMT='date' for date only (the default),
'hours', 'minutes', 'seconds', or 'ns'
for date and time to the indicated precision.
Example: 2006-08-14T02:34:56-0600
-R, --rfc-2822 output date and time in RFC 2822 format.
Example: Mon, 14 Aug 2006 02:34:56 -0600
--rfc-3339=FMT output date/time in RFC 3339 format.
FMT='date', 'seconds', or 'ns'
for date and time to the indicated precision.
Example: 2006-08-14 02:34:56-06:00
-r, --reference=FILE display the last modification time of FILE
-s, --set=STRING set time described by STRING
-u, --utc, --universal print or set Coordinated Universal Time (UTC)
--help display this help and exit
--version output version information and exit
FORMAT controls the output. Interpreted sequences are:
%% 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, 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 time zone (e.g., -0400)
%:z +hh:mm numeric time zone (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)
#date的参数：%%-显示一个%
root@ubuntu:/# date +%%
%
#date的参数：%a-缩写的星期名称，如周六Sat
root@ubuntu:/# date +%a
Sat
#date的参数：%A-完整的星期名称，如周六Saturday
root@ubuntu:/# date +%A
Saturday
#date的参数：%b-缩写的月份名称，如九月Sep
root@ubuntu:/# date +%b
Sep
#date的参数：%B-完整的月份名称，如九月September
root@ubuntu:/# date +%B
September
#date的参数：%c-本地日期
root@ubuntu:/# date +%c
Sat 08 Sep 2018 12:29:20 AM PDT2. 显示日历命令：cal [[month] year]
#列出当前月份日历
root@ubuntu:/# cal
September 2018
Su Mo Tu We Th Fr Sa
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
#列出整年的日历，cal [[month] year]
root@ubuntu:/# cal 2018
2018
January February March
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 1 2 3 1 2 3
7 8 9 10 11 12 13 4 5 6 7 8 9 10 4 5 6 7 8 9 10
14 15 16 17 18 19 20 11 12 13 14 15 16 17 11 12 13 14 15 16 17
21 22 23 24 25 26 27 18 19 20 21 22 23 24 18 19 20 21 22 23 24
28 29 30 31 25 26 27 28 25 26 27 28 29 30 31
April May June
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7 1 2 3 4 5 1 2
8 9 10 11 12 13 14 6 7 8 9 10 11 12 3 4 5 6 7 8 9
15 16 17 18 19 20 21 13 14 15 16 17 18 19 10 11 12 13 14 15 16
22 23 24 25 26 27 28 20 21 22 23 24 25 26 17 18 19 20 21 22 23
29 30 27 28 29 30 31 24 25 26 27 28 29 30
July August September
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7 1 2 3 4 1
8 9 10 11 12 13 14 5 6 7 8 9 10 11 2 3 4 5 6 7 8
15 16 17 18 19 20 21 12 13 14 15 16 17 18 9 10 11 12 13 14 15
22 23 24 25 26 27 28 19 20 21 22 23 24 25 16 17 18 19 20 21 22
29 30 31 26 27 28 29 30 31 23 24 25 26 27 28 29
30
October November December
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 1 2 3 1
7 8 9 10 11 12 13 4 5 6 7 8 9 10 2 3 4 5 6 7 8
14 15 16 17 18 19 20 11 12 13 14 15 16 17 9 10 11 12 13 14 15
21 22 23 24 25 26 27 18 19 20 21 22 23 24 16 17 18 19 20 21 22
28 29 30 31 25 26 27 28 29 30 23 24 25 26 27 28 29
30 313. linux自带的计算器bc
#保留小数位，scale=number，如保留2位小数，scale=2，默认为整数。
#退出计算器：quit
root@ubuntu:/# bc
bc 1.06.95
Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
12+10
22
22*10
220
scale=2
10/100
.10
quit4. 快捷键Tab
作用：命令补全和文件对齐。
#输入ca然后连按2次tab键，会把ca开头的命令查找出来
root@ubuntu:/# ca[tab][tab]
cal caller captoinfo cat catman
calendar capsh case catchsegv cautious-launcher
#在.bash后面连按两次tab是会把该目录下bash开头的文件找出来
root@ubuntu:/# ls -al ~/.bash[tab][tab]
.bash_history .bashrc
#比如我要进入redis-4.0.11目录，这目录太长了，不想输或怕输错，可以只输入readis，然后按tab则会补全目录名。
root@ubuntu:/opt# cd redis[tab]
#按了tab后
root@ubuntu:/opt# cd redis-4.0.11/5. 快捷键ctrl+c
作用：中断命令或程序的运行。
6. 快捷键ctrl+d
作用：退出当前程序，相当于exit或quit