Docs www perl.org

Posted on April 29th, 2025

It is also unique in that all other Perl operators impose a context (usually string or numeric context) on their operands, autoconverting those operands to those imposed contexts. In contrast, smartmatch infers contexts from the actual types of its operands and uses that type information to select a suitable comparison mechanism. The special variables for formats are a subset of those for filehandles. See perlform for more information about Perl’s formats.

The range operator also works on strings, using the magical auto-increment, see below. The smartmatch operator is most often used as the implicit operator of a when clause. Because the smartmatch operator recurses on nested arrays, this will still report that “red” is in the array.

#Bitwise String Operators

On Unix-like (including Linux and Mac OS X) systems, you can access the documentation (for installed modules) with the perldoc command. Perl is an ideal web programming language due to its text manipulation capabilities and rapid development cycle.

Unicode support

The following escape sequences are available in constructs that interpolate, and in transliterations whose delimiters aren’t single quotes (“‘”). In all the ones with braces, any number of blanks and/or tabs adjoining and within the braces are allowed (and ignored). Unary “not” returns the logical negation of the expression to its right. It’s the equivalent of “!” except for the very low precedence. The behavior of a smartmatch depends on what type of things its arguments are, as determined by the following table. The first row of the table whose types apply determines the smartmatch behavior.

When $/ is set to “” and the entire file is read in with that setting, any sequence of one or more consecutive newlines at the beginning of the file is discarded. With the exception of the final record in the file, each sequence of characters ending in two or more newlines is treated as one record and is read in to end in exactly two newlines. If the last record in the file ends in zero or one consecutive newlines, that record is read in with that number of newlines. If the last record ends in two or more consecutive newlines, it is read in with two newlines like all preceding records.

A good setup for Perl on Windows (32 and 64 bit):

Shifting by a value greater than or equal to integer size (in bits) results in zero (all bits fall off), except that under use integer right shifting a negative value by such an amount results in -1. This is unlike in C, where shifting by too many bits is undefined. Is not ok, as the regex engine will end up trying to compile the pattern \, which it will consider a syntax error. Undef is always treated as numeric, and in particular is changed to 0 before incrementing (so that a post-increment of an undef value will return 0 rather than undef). Some operators are instead non-associative, meaning that it is a syntax error to use a sequence of those operators of the same precedence.

#Quoting the delimiter