icon Top 9 categories map      RocketAware > Perl >


Tips: Browse or Search all pages for efficient awareness of Perl functions, operators, and FAQs.


Search Perl pages


By activity
Professions, Sciences, Humanities, Business, ...

User Interface
Text-based, GUI, Audio, Video, Keyboards, Mouse, Images,...

Text Strings
Conversions, tests, processing, manipulation,...

Integer, Floating point, Matrix, Statistics, Boolean, ...

Algorithms, Memory, Process control, Debugging, ...

Stored Data
Data storage, Integrity, Encryption, Compression, ...

Networks, protocols, Interprocess, Remote, Client Server, ...

Hard World
Timing, Calendar and Clock, Audio, Video, Printer, Controls...

File System
Management, Filtering, File & Directory access, Viewers, ...

Treats the string in EXPR as a vector of unsigned integers, and returns the value of the bit field specified by OFFSET. BITS specifies the number of bits that are reserved for each entry in the bit vector. This must be a power of two from 1 to 32. vec() may also be assigned to, in which case parentheses are needed to give the expression the correct precedence as in

    vec($image, $max_x * $x + $y, 8) = 3;

Vectors created with vec() can also be manipulated with the logical operators |, &, and ^, which will assume a bit vector operation is desired when both operands are strings.

To transform a bit vector into a string or array of 0's and 1's, use these:

    $bits = unpack("b*", $vector);
    @bits = split(//, unpack("b*", $vector));

If you know the exact length in bits, it can be used in place of the *.

Source: Perl builtin functions
Copyright: Larry Wall, et al.
Next: wait

Previous: values HASH

(Corrections, notes, and links courtesy of RocketAware.com)

[Overview Topics]

Up to: Binary math

Rapid-Links: Search | About | Comments | Submit Path: RocketAware > Perl > perlfunc/vec.htm
RocketAware.com is a service of Mib Software
Copyright 2000, Forrest J. Cavalier III. All Rights Reserved.
We welcome submissions and comments