Perl Programming Documentation
Download Perl
Explore

Manual

- Overview
- Tutorials
- FAQs
- History / Changes
- License

Reference

- Language
- Functions
- Operators
- Special Variables
- Pragmas
- Utilities
- Internals
- Platform Specific

Modules

- A • B • C • D • E
- F • G • H • I • L
- M • N • O • P • S
- T • U • X

Tools

- Preferences

# rand

Perl 5 version 16.0 documentation
Go to top
Show recent pages
Recently read

# rand

Perl functions A-Z | Perl functions by category | The 'perlfunc' manpage

- rand EXPR

- rand

  Returns a random fractional number greater than or equal to `0` and less than the value of EXPR. (EXPR should be positive.) If EXPR is omitted, the value `1` is used. Currently EXPR with the value `0` is also special-cased as `1` (this was undocumented before Perl 5.8.0 and is subject to change in future versions of Perl). Automatically calls `srand` unless `srand` has already been called. See also `srand`.

  Apply `int()` to the value returned by `rand()` if you want random integers instead of random fractional numbers. For example,

          int(rand(10))

  returns a random integer between `0` and `9` , inclusive.

  (Note: If your rand function consistently returns numbers that are too large or too small, then your version of Perl was probably compiled with the wrong number of RANDBITS.)

  `rand()` is not cryptographically secure. You should not rely on it in security-sensitive situations. As of this writing, a number of third-party CPAN modules offer random number generators intended by their authors to be cryptographically secure, including: Data::Entropy, Crypt::Random, Math::Random::Secure, and Math::TrulyRandom.