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.Shadow trees may be employed in two ways:You can specify only  .In this case, the shadow tree is madeonly for the subdirectory of the Apache source tree and placedside-by-side to this directory.It is named  platform , where plat-form is the platform identification string.Use this option when youThe flexibility of want to build for multiple architectures in parallel.Apache means thatone can easily addYou can specify  Dir.In this case, the shadow tree is madethird-party modules toextend Apache sfor the entire Apache source tree and placed under Dir.Use this optionfunctionality.when you want to build from a read-only media.3.3.2 On-the-Fly Addition of Third-Party ModulesAs you may have recognized in our example installation (Section 3.1 onpage 37), third-party modules can be added to the Apache source tree inthree ways:They can be automatically added and activated by a script.For in-stance, uses this approach.Papersize: (US letter)Cropmarks: (AWL repro)3.3 Configuration Special Topics 57They can be automatically added by a script but activated manually bythe user.For instance, uses this approach.They can be manually added and activated by the user.Most Apachemodules provided by third parties use this approach.This little inconsistency arises because larger modules have more require-ments; to make the life of the user easier, these modules partly automate thesteps.Don t be alarmed if the complex modules differ.The basic way formanually adding a third-party module in APACI involves three steps:1.Obtain the module source.For small modules, it is typically asource file.For larger modules, it may be a directory containingat least , , and a few additional source files(conventionally named ).Third-party modulesdiffer mainly in size:either they are single2.Add the module source to the Apache source tree somewhere undersource modules orthey are contained in.The location selected depends on the module.With atheir own directory.single , you usually place the source underby using.For largermodules that require their own subdirectory under (say,), you must establish this directory manually by run-ning   and later activateit by using.3.Once the third-party modules are fully integrated into the source treeof Apache, you can treat them just like the distributed modules.In bothcases, you enable the module for building viaor.The same idea applies when building as aDSO: a simple or is allthat is needed.3.3.3 Module Order and PermutationsYou may have recognized the harmless-looking APACI optionName1 Name2.We briefly mentioned that it can be used for chang-ing the order of modules.To fully understand this option and its utility, moreknowledge of Apache internals are required.As explained in Chapter 2, the functionality of Apache is implementedby modules.An API dispatches the HTTP request processing.During thisdispatching a fixed module order is used that is derived from the order Use  permutemoduleto change the moduleemployed when building the modules.Actually, it mirrors the order oforder at installationthe / lines in the file , time and the executionorder at runtime.which APACI generates from.When a modulePapersize: (US letter)Cropmarks: (AWL repro)58 Chapter 3: Building Apachecomes later in this file, it is dispatched earlier in the processing.For instance,comes after in this file, so gets controlfor each API step before.As a result, can manipulateURLs before can, but it cannot override results of.For all distributed modules, the order is pre-configured in a reasonableway.Nevertheless, sometimes you may want to change the order of one ormore modules.For instance, to give higher priority over, you would use the following:./configure.--permute-module=alias:rewrite.Now can post-process URLs that were manipulated by.On the other hand, when you add a third-party module, it is alwaysappended to the end of ; hence, it gets the highestpriority by default.This order often isn t reasonable.For instance, when youhave added another URL manipulation module (say, ), it might bereasonable to ensure that it operates after and.Thisgoal can be achieved by using the following APACI command line:./configure.--add-module=/path/to/mod foo.c --permute-module=foo:BEGIN.This command moves to the beginning of the module list and givesit the lowest priority.More complex module order adjustments can be achie-ved by combining multiple options.Papersize: (US letter)Cropmarks: (AWL repro)In this chapter:Configuration TerminologyConfiguration StructureConfiguration ReferenceChapter 4Configuring ApacheBuild a system that even a fool can use,and only a fool will want to use it. Shaw s Principlen this chapter we present a concise but quite complete reference for allIof the configuration directives that Apache provides to both the webmas-ter (in the global server configuration files) and users (in the per-directoryconfiguration files).First, we give a brief description of the various resourceidentifiers used by the directives [ Pobierz całość w formacie PDF ]