# Ns rand

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Man page: http://aolserver.com/docs/tcl/ns_rand.html

**NAME**

- ns_rand - Generate a random number

**SYNOPSIS**

**ns_rand***?maximum?*

**DESCRIPTION**

- This command generates a cryptographically secure random number. If
*maximum*is not specified, the random number returned is a floating-point value n such that 0.0 <= n < 1.0. If*maximum*is specified, it must be a positive integer between 1 and 2147483647, in which case**ns_rand**will return an integer value n such that 0 <= n <= max - 1.

- Internally
**ns_rand**is implemented with the**drand48()**and**lrand48()**standard library functions. An internal random seed is generated the first time**ns_rand**is called after the server starts.

**EXAMPLES**

% ns_rand 0.39938485692

% ns_rand 10 7

**CAVEAT**

- [ns_rand 1] will always produce the result 0. [ns_rand 2] will produce the desired "coin flip" outcome of 0 or 1. This is standard with Java's java.util.Random implementation of nextInt and most other random number libraries.

**SEE ALSO**