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Full Discussion: How to use $variable in conditional sentences?
Top Forums Shell Programming and Scripting How to use $variable in conditional sentences? Post 302997607 by bakunin on Wednesday 17th of May 2017 08:41:52 AM
Old 05-17-2017
I think you mix up two different things: shell scripts and makefiles.

Makefiles (more precisely: the make-utility) work rule-based, so you don't need explicit conditionals - everything is a conditional anyway.

make works like that: you define so-called "dependencies" between files: i.e. you have three object files where each depends on a single source file. Whenever one of the source file changes the corresponding object file has to be generated anew. This is done by executing the code in the rule-definition. For every dependency you can create a rule, but usually you create rules for groups of dependencies: whenever ".c" (the source) changes, the corresponding ".obj" (the object) has to be generated and the rule for this is to call the compiler to compile exactly the one source-file. For this there are "make-variables" like "$@", "$<", etc., which are filled with the name(s) of the files involved in the rule. See the man-page of make for details.

You can also create cascades of these rules: you base .obj-files on .c-files and you base executables on the .obj-files. So, when a source file changes, the corresponding object is generated and in turn this leads to the executable being generated too (by calling the linker to link all the objects to the executable.

You might want to read this little introduction i once wrote.

I hope this helps.

bakunin
This User Gave Thanks to bakunin For This Post:
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LEARN ABOUT CENTOS

shape_depend

SHAPE_DEPEND(1) 					      General Commands Manual						   SHAPE_DEPEND(1)

NAME

       shape_depend - shapeTools RMS determine source-include dependencies

SYNOPSIS

       shape depend [VERSIONS=<selection_rule>] [variants]

DESCRIPTION

       The shape release management system requires for each node system a file named Dependencies, listing the source-derived dependencies of the
       node components. shape depend automatically determines these dependencies and creates an appropriate Dependencies  file.  The  dependencies
       have the form of regular Makefile target-dependents lines without associated build action.

	   Note:  shape  depend  only  works for development of C programs.  It additionally requires a C compiler supporting the -M (generate
	   Makefile dependencies) option.  If this is not the case in your development project, you must either rewrite the action  associated
	   with the depend target (in $(SHAPELIBPATH)/stdtargets) or maintain the Dependencies files manually.

       The  VERSIONS  macro  defines  the  version  selection  rule  to  be  used.  Default is most_recent. See shape_stdrul(7) or the $(SHAPELIB-
       PATH)/stdrules file for other possible settings. You may also use self defined version selection rules as VERSIONS rule.

       If your development environment contains variant definitions, in especially variant definitions that modify the list of	source	components
       to  be  used  during  a	build  operation,  you may also need to specify one or more variants to be set. The project wide variant raster is
       defined in $(SHAPELIBPATH)/stdvar. Check this file and the default variant settings in your Shapefile before invoking shape depend.

INCONVENIENCES

       Regeneration of the Dependencies file due to structural changes of the node system has to be triggered manually. Shape RMS  doesn't  recog-
       nize such changes.

       Variant	specific  Dependencies files (necessary when simultaneousky developing structurally different variants) are not supported. In this
       case you have to run shape depend prior to each build action.

FILES

       $(SHAPELIBPATH)/stdrules
       $(SHAPELIBPATH)/stdtargets
       $(SHAPELIBPATH)/stdvar

SEE ALSO

       shape_RMS (1)

7.8.119 															   SHAPE_DEPEND(1)
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