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Random number between 0-1# awk ' Begin{srand ();p rintf "%.16f\n", Rand ()} 'Random number between 0-20# awk ' Begin{srand (); Sum=rand () *21;printf ("%d\n", Sum)} '# echo ' Expr $RANDOM% 21 '# echo ' Expr $ (expr $ (date +%n)% 20) + 1 '# echo '

Stand on the shoulders of giants!C + + random number generation function rand (), essentially generating pseudo-random sequence numbers.To generate a more random sequence, srand (unsigned num) is required to sow. Common ways Srand ((unsigned) time

Shuffle question: Wash a pair of poker, what good way? Can be washed evenly, and can wash fast? How efficient is the order of chaos relative to a file? On the shuffle problem, there has been a good shell solution, here another three based on the

In the previous article, the experimental environment was built. The protocol analysis can be performed once the IKE/IPSEC protocol is fully run and the relevant output and capture packets are collected. During the analysis, we will use the output

Mint's default wallpaper looks a bit uncomfortable, so I want to change a few pictures to see.Looking for a meeting, did not see the same as windows can randomly cut the function of the wallpaper, all wrote a script implementation.The system is

CentOS6.7 using a non-root user (normal user) compile and install the MySQL database and implement the MySQL database service random auto-start using the Shell Script timed task mode1. About MySQL?MySQL is a relational database management system

Join the MongoDB service to random start vi/etc/rc.local use the VI Editor to open the configuration file and add the following line of code to it/usr/local/mongodb/bin/mongod-dbpath=/usr/local/ mongodb/data/db--fork--port

Use case when for string replacement Copy codeThe Code is as follows :/* Mysql> select * from sales; + ----- + ------------ + -------- + ------ + ------------ + | Num | name | winter | spring | summer | fall | category | + ----- + ------------ + ----

MySQL CASEWHEN statement usage instructions bitsCN.com The case when Statement in the mysql database. The case when statement is used to calculate the condition list and return one of multiple possible result expressions. CASE has two formats: The

MySQL CASEWHEN statement usage instructions. For more information, see. MySQL case when statement instructions. For more information, see. Use case when for string replacement The Code is as follows: /* Mysql> select * from sales; + ----- + --------