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Message: [QUOTE="J Krugman, post: 4787966"] In Programming Perl, Third Edition, page 484, it says: INIT blocks are really just like BEGIN blocks, except they let the programmer distinguish construction that must happen at compile phase from construction that must happen at run phase. When you're running a script directly, that's not terribly important because the compiler gets invoked every time anyway; but when compilation is separate from execution, the distinction can be crucial. The compiler may only be invoked once, and the resulting executable may be invoked many times. The last sentence suggests that if initialization code is stuck in a BEGIN block for a program that is compiled once but run many times, then the initialization will not be properly done except for the very first execution. The only common scenario I could think of where this separation of compilation and execution would happen is something like mod_perl, but then I found this in Practical mod_perl by Bekman and Cholet: Perl calls [INIT and CHECK] blocks only during perl_parse( ), which mod_perl calls once at startup time. Therefore, ...INIT blocks don't work in mod_perl, for the same reason [this doesn't]: panic% perl -e 'eval qq(INIT { print "ok\n" })' So now I'm even more confused. If Perl indeed calls INIT only during perl_parse, then I don't see how the excerpt from PP can be correct, since it seems farfetched that parsing of the program could occur multiple times for a single compilation. My two questions are: 1) notwithstanding the excerpt from PP, in the case of a script intended to be run under mod_perl, would a BEGIN block be the right way to take care of initialization code, like this { my $private; BEGIN { $private = 1 } sub foo { # use $private } } ? And 2) what's a reasonably common, realistic scenario in which compilation would happen once, execution many times, and the distinction between BEGIN and INIT was meaningful in the sense described by the PP excerpt above? TIA! jill P.S. Is this the right forum for this question? [/QUOTE]

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