July 2011
Intermediate to advanced
104 pages
2h 14m
English
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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.
$AUTOLOADcontains 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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