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</Location>

# set Apache::PerlRun Mode for /cgi-perl Alias

SetHandler perl-script

PerlHandler Apache::PerlRun

Options ExecCGI

PerlSendHeader On

</Location>

</IfModule>

These entries create aliases for the Apache::Registry and

Apache::PerlRun modes. The difference between these two modes is

as follows:

Apache::Registry All scripts are compiled and kept in a cache. Every

script is applied as the content of a subroutine. Although this is good

for performance, there is a disadvantage: the scripts must be pro-

grammed extremely carefully, as the variables and subroutines persist

between the requests. This means that you must reset the variables to

enable their use for the next request. If, for example, the credit card

number of a customer is stored in a variable in an online banking

script, this number could appear again when the next customer uses

the application and requests the same script.

Apache::PerlRun The scripts are recompiled for every request. Vari-

ables and subroutines disappear from the namespace between the

requests (the namespace is the entirety of all variable names and rou-

tine names that are deﬁned at a given time during the existence of a

script). Therefore, Apache::PerlRun does not necessitate painstak-

ing programming, as all variables are reinitialized when the script is

started and no values are kept from previous requests. For this rea-

son, Apache::PerlRun is slower than Apache::Registry but still

a lot faster than CGI (in spite of some similarities to CGI), because no

separate process is started for the interpreter.

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22.9. Active Contents