Operation of the underlying command

1. Language support

$ echo $LANG (displays the currently supported languages)

Running result: ZH_CN. UTF-8

$ lang=en_us (modified language for English languages)

2. Display the date of the command

$ date

Operation Result: Monday, July 13, 2015 17:39:40 CST

$ date +%y/%m/%d

Run Result: 2015/07/13

$ date +%h:%m

Run Result: 17:40

3. commands for displaying calendars

$ CAL [[month] year] (basic syntax)

$ cal (Lists the current month's monthly calendar)

$ cal 2015 (show calendar for the full year)

$ cal 09 2015 (Show September 2015 calendar)

4. Calculator (only output integers by default)

$ BC

Scale = number (numbers represent the digits after the decimal point)

Operation of the underlying command