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This article is about how Linux generates random numbers and strings. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

Generate random numbers

1. Use the system's $RANDOM variable

> echo $RANDOM 14587

two。 Use date +% s% N

> date +% s%N1529584024896587259

3. Use / dev/random or / dev/urandom

/ dev/random stores the real-time data of the current running environment of the system, and is a blocked random number generator. Reading sometimes needs to wait, so try to avoid using it.

/ dev/urandom non-blocking random number generator, read operation will not cause blocking.

> cat / dev/urandom | head-n 10 | cksum | awk-F'{print $1} '1198074148

Generate random strings

1. The full name of linux uuid,uuid is a universal unique identification number. The format contains 32 hexadecimal digits and is divided into 5 segments with a'- 'connection number. 32 characters in the form 8-4-4-4-12.

> cat / proc/sys/kernel/random/uuid6fcae1aa-ab46-435a-8531-250ccb54ed8e

two。 Use md5sum

# generate 10-bit random strings using date > date +% s% N | md5sum | head-c 10bb791e69d4# generate 10-bit random strings using / dev/urandom > cat / dev/urandom | head-n 10 | md5sum | head-c 10909587db4c > head-c 10 / dev/random | base64tBIDqQcaQ+qvkA==

3. Use openssl

> openssl rand-hex 103822e40bdcc2d1c6ee5f Thank you for reading! This is the end of this article on "Linux's method of generating random numbers and strings". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it for more people to see!

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