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Perl Language Reference Manual
by Larry Wall and others
Paperback (6"x9"), 724 pages
ISBN 9781906966027
RRP £29.95 ($39.95)

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29.23 W

A message printed to the STDERR stream to the effect that something might be wrong but isn't worth blowing up over. See and the "Perl pragma to control optional warnings" (warnings) in the Perl Library Reference Manual (Volume 1) pragma.
watch expression
An expression which, when its value changes, causes a breakpoint in the Perl debugger.
A character that moves your cursor but doesn't otherwise put anything on your screen. Typically refers to any of: space, tab, line feed, carriage return, or form feed.
In normal "computerese", the piece of data of the size most efficiently handled by your computer, typically 32 bits or so, give or take a few powers of 2. In Perl culture, it more often refers to an alphanumeric identifier (including underscores), or to a string of nonwhitespace characters bounded by whitespace or string boundaries.
working directory
Your current directory, from which relative pathnames are interpreted by the operating system. The operating system knows your current directory because you told it with a chdir ( ) or because you started out in the place where your parent process was when you were born.
A program or subroutine that runs some other program or subroutine for you, modifying some of its input or output to better suit your purposes.
What You See Is What You Get. Usually used when something that appears on the screen matches how it will eventually look, like Perl's format ( ) declarations. Also used to mean the opposite of magic because everything works exactly as it appears, as in the three-argument form of open ( ).
ISBN 9781906966027Perl Language Reference ManualSee the print edition