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bytes(3)
NAME
  bytes - Perl pragma to force byte semantics rather than character semantics

SYNOPSIS
      use bytes;
      ... chr(...);	  # or bytes::chr
      ... index(...);	  # or bytes::index
      ... length(...);	  # or bytes::length
      ... ord(...);	  # or bytes::ord
      ... rindex(...);	  # or bytes::rindex
      ... substr(...);	  # or bytes::substr
      no bytes;

DESCRIPTION
  The "use bytes" pragma disables character semantics for the rest of the
  lexical scope in which it appears.  "no bytes" can be used to reverse the
  effect of "use bytes" within the current lexical scope.

  Perl normally assumes character semantics in the presence of character data
  (i.e. data that has come from a source that has been marked as being of a
  particular character encoding). When "use bytes" is in effect, the encoding
  is temporarily ignored, and each string is treated as a series of bytes.

  As an example, when Perl sees "$x = chr(400)", it encodes the character in
  UTF-8 and stores it in $x. Then it is marked as character data, so, for
  instance, "length $x" returns 1. However, in the scope of the "bytes"
  pragma, $x is treated as a series of bytes - the bytes that make up the
  UTF8 encoding - and "length $x" returns 2:

      $x = chr(400);
      print "Length is ", length $x, "\n";     # "Length is 1"
      printf "Contents are %vd\n", $x;	       # "Contents are 400"
      {
	  use bytes; # or "require bytes; bytes::length()"
	  print "Length is ", length $x, "\n"; # "Length is 2"
	  printf "Contents are %vd\n", $x;     # "Contents are 198.144"
      }

  chr(), ord(), substr(), index() and rindex() behave similarly.

  For more on the implications and differences between character semantics
  and byte semantics, see perluniintro and perlunicode.

LIMITATIONS
  bytes::substr() does not work as an lvalue().

SEE ALSO
  perluniintro, perlunicode, utf8

Index for Section 3

Alphabetical listing for B

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