Unix Make Love Commands:
The result of the expansion of this function is the empty string. The flavor function, like the origin function, does notoperate on the values of variables but rather it tells you somethingabout a variable. Specifically, it tells you the flavor of avariable (see The Two Flavors of Variables). If variable is the name of a built-in function, the built-in functionis always invoked (even if a make variable by that name alsoexists). When reading files, it is an error to provide a text value. Might be useful if the value of find_files references the variablewhose name is ‘Esta-escrito-en-espanol!
For example, if you have a function in a programthat is buggy, are you going to debug by running the whole program orjust the function? I’d hope you’d (barring unusual cases) choose to runjust the function so that you don’t have to worry about bugs elsewherein your code. If you are debugging aproblem with some software, you don’t want to have to assume that a fullGUI is working properly.
The usual behavior assumes that your purpose is to get the specifiedtargets up to date; once make learns that this is impossible, itmight as well report the failure immediately. Thisis why Emacs’ compile command passes the ‘-k’ flag bydefault. Sometimes the failure of a certain recipe line does not indicate a problem.For example, you may use the mkdir command to ensure that adirectory exists. If the directory already exists, mkdir willreport an error, but you probably want make to continue regardless. We will change how this aspect of make works if we find a betteralternative.
The string is expanded by make using normalmake expansion rules. The result of the expansion is convertedinto a Guile string and provided as the result of the procedure. This causes one special rule whose target is (%) to match. Thisrule updates the target a(m) by copying the file minto the archive. For example, it will update the archive member targetfoo.a(bar.o) by copying the file bar.o into thearchive foo.a as a member named bar.o.
By mastering the Unix command line interface, you’ll be better equipped to handle complex tasks, automate repetitive processes, and become a more efficient and productive user. So, whether you’re a seasoned professional or a beginner, keep this cheat sheet handy and continue to explore the vast and powerful world of Unix commands. The man pages are the built-in documentation for Linux commands. You can access them by typing “man” followed by the name of the command you want to learn about. For example, to learn about the “ls” command, you would type “man ls”. The man pages provide detailed information on how to use each command, as well as examples and options.
You can also essentially create your ownfunctions by using the call built-in function. The value of .RECIPEPREFIX can be changed multiple times; once setit stays in effect for all rules parsed until it is modified. Contains the name of each makefile that is parsed by make, inthe order in which it was parsed.
Here is a very simple example using GNU Guile to manage writing to afile. These Guile procedures simply open a file, allow writing to thefile (one string per line), and close the file. Note that because wecannot store complex values such as Guile ports in makevariables, you could try this out we’ll keep the port as a global variable in the Guileinterpreter. A list is converted recursively according to the above rules. Thisimplies that any structured list will be flattened (that is, a resultof ”(a b (c d) e)’ will be converted to the make string’a b c d e’).
N.o is made automatically from n.c witha recipe of the form ‘$(CC) $(CPPFLAGS) $(CFLAGS) -c’. If you are working on the program size, you might want to say’make size’ so that only the files of that program are recompiled. You can also specify a different goal or goals with command linearguments to make. Use the name of the goal as an argument.If you specify several goals, make processes each of them inturn, in the order you name them.
The value function provides a way for you to use the value of avariable without having it expanded. The result of the function’s processing is substitutedinto the makefile at the point of the call, just as a variable mightbe substituted. Each word in this variable is a new prerequisite which is added totargets for which it is set. These prerequisites differ from normalprerequisites in that they do not appear in any of the automaticvariables (see Automatic Variables).
Note that expansion using ‘%’ in pattern rules occursafter any variable or function expansions, which take placewhen the makefile is read. See How to UseVariables, and Functions for Transforming Text. A file cannot be intermediate if it is mentioned in the makefile as a targetor prerequisite, so one way to avoid the deletion of intermediate files is byadding it as a prerequisite to some target.
You would want to write a rulefor foo.o with no recipe if you need to specify additionalprerequisites, such as header files, that the implicit rule cannotsupply. The built-in implicit rules use several variables in their recipes sothat, by changing the values of the variables, you can change the way over here theimplicit rule works. For example, the variable CFLAGS controls theflags given to the C compiler by the implicit rule for C compilation. You can use the variable MAKEFILES to cause all sub-makecommands to use additional makefiles. The value of MAKEFILES isa whitespace-separated list of file names.
Due to a limitation of the archive format, archive member time stampsare always low resolution. You need not list archive members asprerequisites of .LOW_RESOLUTION_TIME, as make does thisautomatically. Here we’ve also declared that the foo sub-directory cannot bebuilt until after the baz sub-directory is complete; this kind ofrelationship declaration is particularly important when attemptingparallel builds.
If you do put MAKEFLAGS in your environment, you should be sure notto include any options that will drastically affect the actions ofmake and undermine the purpose of makefiles and of makeitself. For instance, the ‘-t’, ‘-n’, and ‘-q’ options, ifput in one of these variables, could have disastrous consequences and wouldcertainly have at least surprising and probably annoying effects. Adding a variable’s value to the environment requires it to be expanded. Ifexpanding a variable has side-effects (such as the info or evalor similar functions) then these side-effects will be seen every time acommand is invoked.
Regardless of how make is invoked, the targets one, two,and three will be run serially. Will not let make start more than one job if the load average isabove 2.5. The ‘-l’ option with no following number removes theload limit, if one was given with a previous ‘-l’ option. On MS-DOS, if SHELL is not set, the value of the variableCOMSPEC (which is always set) is used instead. Since ‘cp -p’ discards the sub-second part of src’s timestamp, dst is typically slightly older than src even whenit is up to date.
The directory for installing locale-specific message catalogs for thispackage. By default, it should be /usr/local/share/locale, butit should be reference written as $(datarootdir)/locale. (If you areusing Autoconf, write it as ‘@localedir@’.) This directoryusually has a subdirectory per locale.