mysql -uroot -p --prompt="\\u@\\h:\\d \\r:\\m:\\s>"

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.1.60-log Source distribution
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Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
root@localhost:(none) 11:04:23>

[mysql] 
prompt=mysql(\\u@\\h:\\d)> 

default-character-set=utf8 

Option  Description
\c  A counter that increments for each statement you issue
\D  The full current date
\d The default database
\h The server host
\l The current delimiter (new in 5.1.12)
\m  Minutes of the current time
\n  A newline character
\O  The current month in three-letter format (Jan, Feb, …)
\o  The current month in numeric format
\P  am/pm
\p The current TCP/IP port or socket file
\R  The current time, in 24-hour military time (0–23)
\r  The current time, standard 12-hour time (1–12)
\S  Semicolon
\s  Seconds of the current time
\t  A tab character
\U   www.jb51.net 
Your full user_name@host_name account name

\u Your user name
\v  The server version
\w  The current day of the week in three-letter format (Mon, Tue, …)
\Y  The current year, four digits
\y  The current year, two digits
\_  A space
\   A space (a space follows the backslash)
\'  Single quote
\"  Double quote
\\  A literal “\” backslash character
\x
x, for any “x” not listed above