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Perl Pocket Reference, 5th Edition by Johan Vromans

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Special Subroutines

Special subroutines are user defined, but are called by Perl while processing the program. They can be used to change the order in which parts of a program are executed.

[ sub ] AUTOLOAD block

The code in block is executed when the program calls an undefined subroutine. $AUTOLOAD contains the name of the called subroutine, and @_ contains the parameters.

[ sub ] BEGIN block

The code in block is executed immediately when compilation of the block is complete.

[ sub ] CHECK block

Executed (in reverse order) when the compilation of the program finishes.

[ sub ] END block

Executed in reverse order when the Perl interpreter terminates. Inside the END blocks, $? contains the status with which the program is going to exit.

[ sub ] INIT block

Executed immediately before the Perl interpreter starts executing the program.

[ sub ] UNITCHECK block

Executed (in reverse order) when the compilation of the program unit finishes.

perlsub, perlmod.

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