Global Special Variable Types in Perl



There are various global special variables in Perl. We have listed them in different blocks based on their usage and nature −

Global Array Special Variables

@ARGV The array containing the command-line arguments intended for the script.
@INC The array containing the list of places to look for Perl scripts to be evaluated by the do, require, or use constructs.
@F The array into which the input lines are split when the -a command-line switch is given.

Global Hash Special Variables

%INC The hash containing entries for the filename of each file that has been included via do or require.
%ENV The hash containing your current environment.
%SIG The hash used to set signal handlers for various signals.

Global Special Filehandles

ARGV The special filehandle that iterates over command line filenames in @ARGV. Usually written as the null filehandle in <>.
STDERR The special filehandle for standard error in any package.
STDIN The special filehandle for standard input in any package.
STDOUT The special filehandle for standard output in any package.
DATA The special filehandle that refers to anything following the __END__ token in the file containing the script. Or, the special filehandle for anything following the __DATA__ token in a required file, as long as you're reading data in the same package __DATA__ was found in.
_ (underscore) The special filehandle used to cache the information from the last stat, lstat, or file test operator.

Global Special Constants

__END__ Indicates the logical end of your program. Any following text is ignored, but may be read via the DATA filehandle.
__FILE__ Represents the filename at the point in your program where it's used. Not interpolated into strings.
__LINE__ Represents the current line number. Not interpolated into strings.
__PACKAGE__ Represents the current package name at compile time, or undefined if there is no current package. Not interpolated into strings.
Updated on: 2019-11-29T11:51:07+05:30

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