Literals

• Numeric
• 123 1_234 123.4 5E-10 0xff (hex) 0377 (octal)
• String
• • 'abc'
  • Literal string, no variable interpolation or escape characters, except \' and \\. Also: q/abc/. Almost any pair of delimiters can be used instead of /.../.
  • "abc"
  • Variables are interpolated and escape sequences are processed. Also: qq/abc/.

    Escape sequences: \t (Tab), \n (Newline), \r (Return),\f (Formfeed), \b (Backspace),\a (Alarm), \e (Escape), \033 (octal), \x1b (hex), \c[ (control).

    \l and \u lowercase/uppercase the following character. \L and \U lowercase/uppercase until a \E is encountered. \Q quotes regular expression characters until a \E is encountered.

  • `command`
  • Evaluates to the output of the command. Also: qx/command/.
• Array
• (1, 2, 3)

  ( ) is an empty array.

  (1..4) is the same as (1,2,3,4), likewise ('a'..'z').

  qw/foo bar.../ is the same as ('foo','bar',...).

• Array reference
• [1,2,3]
• Hash (associative array)
• (key1, val1, key2, val2,...)

  Also (key1 => val1, key2 => val2,...)

• Hash reference
• {key1, val1, key2, val2,...}
• Code reference
• sub { statements }
• Filehandles
• STDIN, STDOUT, STDERR, ARGV, DATA.

  User-specified: handle, $var.

• Globs
• <pattern> evaluates to all filenames according to the pattern. Use <${var }> or glob $var to glob from a variable.
• Here-Is
• <<identifier

  Shell-style "here document."

• Special tokens
• _ _FILE_ _: filename; _ _LINE_ _: line number;

  _ _END_ _: end of program; remaining lines can be read using the filehandle DATA.