Makefile check environment variable I want to print this value using echo command in make files. See Variables from the Environment. env file in your directory and put your variables there; install and setup direnv for your shell configure it to allow . The nearest thing I can find is to say: CFLAGS:= 继续makefile变量的学习 7. Your original shell snippet could be something like: result=$(if $(filter y,${CHECK}),true,false) (TIMTOWTDI applies). Provide details and share your research! But avoid . When make is run in a shell, any environment variable present in the shell is transformed into a make Makefile check if variable is defined. Makefile: conditionals inside define. You may also want to set -e option (aka --environments-override) on, and your environment variables will override assignments made into makefile (unless these An environment variable ENVAR that exists when you invoke nmake is inherited as an nmake macro of the same name. On 3. And to pass this to makefile I have to set it inside bash-script. I tried this: gulp:=. Steps: run make test setting env: export TEST_ENV_ONE=OneString; In this case make is the process, and the makefile can change environment variables in the make process, and any child processes make invokes (e. I like to have CFLAGS defined in my environment for other reasons. In addition, the default goal is never taken from one Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. However, an explicit assignment in the makefile, or with a command argument, overrides the environment. 1)? In any case, the usual way would be add a flag to configure that turns on a certain feature. – Roland Weber. That said, we can include the appropriate environment file in If you really mean to test an environment variable (as opposed to a make variable), then simply do so in the commands: if test -z "$$X"; then X=0. Commented Jun 7, Downside to this is that . 2021-03-04. One minute read. env, which make requires to be escaped. I check whether JAVA_HOME is defined in the environment in a Makefile using. You can add a semicolon and a backslash after your export line and it will work. It is very easy to Inside my makefile, I need to set a variable based on an environment variable called MY_SERVER_ENV. How could I abort a make/makefile execution based on a makefile's variable not being set/valued? I came up with this, but works only if caller doesn't explicitly run a target (i. 3rdparty. Makefile export variable for triggering prerequisite. If your goal is to have a set of environment variables defined for any user shell (I assume this means interactive shell), you can simply add these definitions to the shell's startup file (. txt, which is not what I want. env,env/integ. Also the fact that make treats tab as special means that it will attempt to interpret tabs as meaningful inside . ifeq (undefined,$(origin JAVA_HOME)) #CALL with defaults else #CALL according to the variable endif But when I process this in a Makefile. I don't think that CMake does such things: they are greatly generator-specific (in your case - Make-specific). I already tried searching for environment variable testing in a Makefile but with no success so far. Neither is it an option to globally modify the PATH variable to include a sh. exe (too much potential conflict between I'd like my makefile to crash if an environment variable is not set. If what you want is for the make program to change the environment of the caller of make , then as @chepner says that's not possible: this is an operating system That's not an answer to the question how to set a Makefile variable if it isn't set. Makefile test if variable is not empty. /configure script should fail on enabling mistyped parameters. Posts; Tags; Search; Get Environment Variables From a File into Makefile. 7. In python, you can print(os. But, I don't get the exact syntax of it. html in Android NDK package, or here) states:LOCAL_SRC_FILES. This is a list of source files that will be built for your module. zshenv. runs make only). $ go test -tags=integration -v -race For a variable VAR defined in the environment and automatically imported into GNU Make $(origin VAR) has the value environment. I also thought about creating a phony target to check for the variable, with test, but then the phony target would be executed every time and, consequently, target also would. Variable Assignment in Makefile. This is what I have so far: ifneq ($(shell echo $${VIRTUAL_ENV:+True}),True) $ Check if environmental variable is set in makefile. env) $(eval export sed 's/=. The target: Checking environment variable in make through automake. Yes, . Check out $(origin) function. Long story short, building a mono project just requires importing msbuild. ifeq is not a valid command for the shell. (In some other versions of make, variables are called macros. Environment Variables. VARIABLES and filtering them out. $ cat Makefile all: @echo $(FOO) Now with no variable set, big surprise, we get nothing: $ printenv | grep FOO $ $ make $ With the variable just set, but not exported: For example, to set the CC environment variable, you can use the following syntax: set(ENV CC gcc CACHE INTERNAL "") Checking Environment Variables. I think it is easy but I'm just missing something. Variables in make can come from the environment in which make is run. To configure your There is a workaround, however: explicitly pass the exported variable as an environment variable to the shell function: How to export environment variables in Makefile. I also have an environment variable that I would like to use within the makefile. – Try to play with LOCAL_PATH variable. If you change the value of ENVVAR in the makefile, like: ENVAR=newval then environment variable ENVAR assumes the value newval for commands that are run by the makefile. 2. As it stands, make creates a shell that runs the export, and then creates another shell to run the test (so the second shell has no clue about the exported variable). When make is run in a shell, any environment variable present in the shell is transformed into a make Unfortunately, Makefile doesn’t automatically have access to the root . Tagged with tooltip, makefile. The shell gets result=true or result=false depending on the value of the make variable CHECK. The following configure. When you use a variable in a Makefile task and you want to make it mandatory and check it before run the effective task, Do you have your environment variable set to true, or probably to some other truish-value (e. In addition, the default goal is never taken from one When on an environment that does not have the variable, make fails and the program is not compiled. and the latter doesn’t see the environment variable. Several automatic variables are given new values for each rule. For example, to check if the PATH environment variable is set, you can use the following syntax: It's also doable without saving all the . any solution to that? Re-define ARDMK_DIR in the project Makefile. Every environment variable that make sees when it starts up is transformed into a make variable with the same name and value. that the echo command echos the text, that Vim inserted into the command line while the make command gets the the variable value from the environment. You are testing an environment variable in a shell command executed by make. Makefile: all: echo "Hello ${FOO}" . A variable is a name defined in a makefile to represent a string of text, called the variable’s value. ) Note that this variable should be used only in special circumstances. bin/gulp ifeq ($(MY_SERVER_ENV), 'prod') branch:=produc I am trying to figure out how to use env variables in makefiles. PORT=3000. Set and check for empty var inside a target. 13 makefile contains instruction to call Microsoft compiler, cl. Makefile define variable using if. env file. ONESHELL will do that since it uses far fewer shell invocations. You have several options to set up variables from outside your makefile: From environment - each environment variable is transformed into a makefile variable with the same name and value. . How to get environment variables from a file into Makefile > $ techctl. 1. *//' env/$(1). Makefile: export DB_HOST=$(shell grep DB_HOST . In a makefile I'm trying to. e. $ export SOME_ENV=someTest. – Variables from the Environment: use of variables from the environment is not recommended. Say I have this Makefile. The best way to do this is to create your own linker script with the environment variables you want to export, and have the original linker script include it as so: makefile: foo: echo SOMEVAR=$(SOMEVAR) > environment_linker_script ld I have a makefile and a . 51. The situation is that make is in the PATH (or is being directly invoked) but an acceptable shell (i. If the variable needed for a compile process, then you could create some wrapper around the compiler and pass that wrapper to I’d like the Makefile to check if an environment variable is set (sort of How to ensure Makefile variable is set as a prerequisite?): 2) check the variable: set | grep MACHTYPE (I expect "x86_64-pc-linux-gnu". Assignments to variables on the command line override the values from the makefile. : 3rdparty: $(MAKE) -f Makefile. To check if an environment variable is set, you can use the if command. So enhancing the Makefile above to: $(warning Accessing shell variables. Everything builds find as expected. env) endef All the make variables are gone by the time the shell gets its hands on the recipe. I have a list defined in the make file and the user is supposed to set an environment variable which I need to find in this list. A directive is an instruction for make to do something special while reading the . EDIT completely reworked the answer after the OP explained in a comment that he wants the environment variables to be defined for any user shell. Check if environmental variable is set in makefile. Is there a way using gnu make to do this? I want to do this outside any recipe, before make starts building any targets. ) 4) At the top of the makefile add the line $(info MACHTYPE is $(MACHTYPE)) and run make . 05; echo "X undefined, I am trying to set an Environment variable in a Makefile, so it can be used in another program running in the sam shell as make, but after make has run. As documentation (docs/ANDROID-MK. How do I check if an environment variable is set in cmake. ) 3) check the variable again: printenv | grep MACHTYPE (I expect nothing, no output. The simple makefile example shows a variable definition for objects as a list of all object files (see Variables Make Makefiles Simpler). It is not wise for makefiles to depend for their functioning on environment variables set up outside their control, since this would cause different users to get different results from the same makefile. A variable is a name defined in a makefile to represent a string of text, called the variable's value. You may check the variable in the CMakeLists. Another method is to enable overriding of unconditionally set variables by environment variables using command switch -e: The syntax to access the environment variable in make is like other variables in make #export the variable. Just like nmake, To check the value of some environment variable in command prompt window use ECHO command followed by environment variable surrounded with percent signs: The trick with makefile syntax is that when a line after a target begins with a tab character, this lines is not a make statement anymore, but rather is passed (after $ variables and functions are evaluated) to the shell, as a command that is supposed to build the target. run a shell command and capture the output in a make variable; do something if the variable is not empty; I've created this simplified makefile to demonstrate my problem. That is to say that. Alternatively, you can set all those variables to its default values in the makefile. But from there, you cannot set a variable that applies elsewhere in the Makefile. If you use operation, then the shell command will get evaluated every time. abc: ABC=123 all-abc: abc $(TARGETS) doesn't work. env file, which might look something like this. 10 Variables from the Environment. VARIABLES was modified in your makefile, the two most voted answers won't catch it. Makefile: run based on test of variable. Per Wikipedia, . If SQL_HOST and SQL_PASSWORD are variables defined earlier in your Makefile, (rather than environment variables) you need to write it like this: SQL_HOST=localhost SQL_PASSWORD=hunter2 sqlcmd: docker-compose run sqlcmd sqlcmd -S sqlserver -U "$(SQL_HOST)" -P "$(SQL_PASSWORD)" The best way to prove that an environment variable has been set, is to query this environment variable inside another program that make wil call. GitHub Gist: instantly share code, notes, and snippets. If the environment variable MAKEFILES is defined, make considers its value as a list of names (separated by whitespace) of additional makefiles to be read before the others. Variables in the environment become make variables. The difference between the example below and those which use := is the := assignment happens once (when it is encountered) and for all. You can specify a value in the makefile, either with an assignment (see Setting Variables) or with a verbatim definition (see Defining Multi-Line Variables). Moreover, if one of the original . !IFDEF VAL echo %VAL% !ELSE echo "NOT SET" !ENDIF I know that on linux you can use ifeq, but there is no such thing in the windows makefile. ac snippet adds a --enable-gcov flag to configure; it will also do a printout whether it has enabled gcov or not: put a . in your directory where the Makefile is installed; from now running make will use your environment variables; I used this to test. ifeq ($(MY_FLAG),) abort: ## This MUST be the first target :( ugly @echo Variable MY_FLAG not set && false endif all: @echo MY_FLAG=$(MY_FLAG) The environment variable OS is always set to "Windows_NT" on different Windows versions (see %OS% environment variable on Wikipedia). Variables specified on make command line override the values assigned in makefile: TMPDIR := "/tmp" test: @echo $(TMPDIR) And then: make TMPDIR=whatever whatever It is generally considered a bad practice for makefiles to depend on environment variables because that may lead to non-reproducible builds. make linux unix. GNU Make: Test if either OR variables are null or undefined. Makefiles can indeed reference environment variables, which is exactly what CLASSPATH is in this context. # . someTest. This works much like the include directive: various directories are searched for those files (see Including Other Makefiles). I have found some documentation but I am having a hard time seeing how to use it in my case. variable to a value within a range/list. To complete previous anwswer from meuh, if you would like env file to be dynamic, you could define a setup function. @echo $(MACHTYPE) Upon executing the above command empty string is getting displayed. create env/local-dev. Recursively expanded variables set with = are a bit more "lazy"; references to other variables remain until the variable You need to use the $(shell operation) command in make. env) @echo " - setup env $(ENV_FILE)" $(eval include env/$(1). Every environment variable that make sees when it starts up is transformed into a make variable with the same Environment Variables. 0. Please help. I have a Makefile that has a variable that needs to have a default value in case when variable is unset or if set but has null value. But in case you want that you need to override the settings of the make variable MYLIB to something different from what it is specified in the Makefile WITHOUT having to edit the Makefile for that, then it is very simple: In your make invocations, specify MYLIB on the commandline with a value of your choice , like as: I want to check if the following is the correct/acceptable way of reading environment variables from . Hot Network Questions Has there been an official version of the Cerberus for D&D? Unfortunately, Makefile doesn’t automatically have access to the root . am with automake I get two erros: else without if endif without if Looks like automake does not digest the ifeq. I have a workaround, though it's not pretty -- the original script is called with $(shell), so it does not have access into the environment variables. env in a Makefile. env syntax is not a subset of the Makefile syntax because there are certain symbols allowed in . make --eval='print-tests: @echo TESTS $(TESTS) ' print-tests You can insert the required TAB character in the command line In a makefile, I have the following: SHELL = $(SOME_DIRECTORY)/sh showme: echo $(SHELL) This is on MS Windows. but if the variable was not defined, the target will understand /file. If you've exported the environment variable: export demoPath=/usr/local/demo you can simply refer to it by name in the makefile (make imports all the environment variables you have set): DEMOPATH = ${demoPath} # Or $(demoPath) if you prefer. As it is a non-interactive shell, it is the value from . But I would like to be sure that CFLAGS is unset when I invoke make on the 3rd party Makefile. 5. Makefile - Function to check empty environment variables. This is an example of what I would like to do : A variable definition is a line that specifies a text string value for a variable that can be substituted into the text later. My application creates an environment variable MACHTYPE with a value say "DELLMACHINE". This is against the whole purpose of most makefiles. Only list the files that will be passed to a compiler, since the build system automatically computes dependencies for you. I'm trying to export environment variables so that they can be accessed in the parent shell MakeFile: export-vars: # extract vars from text file - remove comments Export a bash environment variable from a Makefile that is the populated from a command. Testing if a file exists in a make file. and in this case I wanted to ensure that when importing msbuild the Makefile defines the required variables. Neither make a or make b executes the body of the if, I don't understand why not. Classpath is a parameter in the Java Virtual Machine or the Java compiler that specifies the location of user-defined classes and packages. That doesn't set the environment variable in the current shell: it only sets that environment variable in the env command. env files I am trying to write a function to check if multiple environment variables are set. exe. I've thought about having another dependency before the real ones that just sets the environment variable but I don't think the environment persists across targets. env | cut -d '=' -f2) export I thought you wanted to check that the shell environment variable is set properly. 6 How to Use Variables. 1多行变量 使用define关键字设置变量的值可以有换行，有利于定义一系列的命令，例如前面的“命令包”，define 指示符后面跟的是变量的名字，而重起一行定义变量的值，定义是以 endef 关键字结束。其工作方式和“=”操作符一样。变量的值可以包含函数、命令、文 but that doesn't work because the dependencies are processed before the variable is set. For example the symbols: # and $. These values are substituted by explicit request into targets, prerequisites, recipes, and other parts of the makefile. An alternative of OS is the environment variable MSVC (it checks the presence of MS Visual Studio, see example using Visual C++). env HOSTNAME = localhost PORT = 3000 That said, we can include the appropriate environment file in our Makefile . How to Edit Environment Variables There are some minor differences between the user interfaces of Windows 10 and Windows 11, but the basic process of editing environment variables is the same. If you want your makefile to determine what the underlying OS type really is, have it check first for the environment variable PROCESSOR_ARCHITEW6432, which will tell a 32-bit application the actual OS architecture. Guard a variable in a Makefile. sh. How can I achieve this? I need this, as I invoke make inside a shell script and the value required by the makefile can be passed from the shell as $1. 3. Share. env: FOO=alex If you don't want to modify the Makefile itself, you can use --eval to add a new target, and then execute the new target, e. ld does not import any variables from the environment, so it cannot use them directly. 4 The Variable MAKEFILES. bat that runs the makefile. exe and linker, link. In this example, Makefile - How to check if variable is not empty and is one of the two values. Accessing shell variables. Tried hard, but can't find it. makefile - check variable is one of them. I have a Makefile target, in which I have to check the value of an environment variable. env file with some content; define a method to load this; define setup_env $(eval ENV_FILE := env/$(1). Asking for help, clarification, or responding to other answers. All exported shell environment variables are accessible like so: $(MYBASEDIR) Example. You should export the variable using Make’s constructs: export SOME_ENV := someTest test: go test or specify the variable inline: test: SOME_ENV=someTest go test or ensure both lines are run in the same shell: test: export SOME_ENV=someTest && \ go test I want to check if my environment variable is set, but this doesn't work. You can either use: $ export INTEGRATION=true $ make help (set the variable in the shell, so all subsequent commands can see it until you un-export it again), or you can use: $ env INTEGRATION=true make help Unfortunately that would complicate my Makefile worse than my existing solution. on shell prompt, SOME_ENV is set and the next command (go test) internally picks . If PROCESSOR_ARCHITEW6432 isn't set, then fallback to checking PROCESSOR_ARCHITECTURE. Require an environment variable to be set in a Makefile target. What I suggest forces make to treat the two lines as one. exe) is NOT in the PATH. getenv("MURDOC")) to truly query the environment variable. Update: This is not possible according to accepted answer with comments. There's also an directive that you can add to a makefile that tells GNU It's not very clear what it is exactly that you are after. This way the user have to specify the values of those variables only if the defaults are not suitable. In Makefile assign path variable dependent if path exists. This method even works with recursive use of make where the variables specified on command-line are automatically passed to the new make process. These values are substituted by explicit request into targets, Every environment variable that make sees when it starts up is transformed into a make variable with the same name and value. This way the non-conditionally set variables get overridden too. Only doing echo $(BLAH) is merely evaluating Makefile's key/value mechanism inside the Makefile. That said it also drastically changes the semantics of the build (since failures on any given line won't abort the build immediately) at least not without "modif[ing] . , recipes make runs) can inherit that value. e. $ cat Makefile all: @echo $(FOO) Now Variables in make can come from the environment in which make is run. It is a QA check to make sure user sets the env. The library's build is being invoked from another makefile, so that I say e. However, when I run it prints an With GNU Make, you can use shell and eval to store, run, and assign output from arbitrary command line invocations. mk and define the 3 APP_ variables. SHELLFLAGS to add the -e option to the shell which will cause any failure anywhere in the command line to cause the shell to fail" and -e isn't 6. Conditional change of Makefile variable (Application to unit testing of static function) Related. env files; run direnv allow . /node_modules/. bashrc for bash). The real power of make variables starts to show when you pair them with environment variables. g. in the terminal, export MY_ENV_VARIABLE="hello world" #in the makefile (replace before call) echo $(MY_ENV_VARIABLE) This performs the substitution before executing the commmand. If you are writing to a log file, you don't want the log file name to change every time you access it in a single make command. Edit: I use nmake from cl2022 in cmd. Here is the code . In my case I want to make the below more general. txt itself, so it will fail even on configuration stage when the variable is not set. I have (kind of) specific use-case where I need to do these steps: run command1; assign output form command2 to env variable; run command3 which read env variable assigned in step 2; This is the makefile implementing the steps described above. Make does not know anything about shell variables. This target filters out and prints all the variables that were defined in a makefile: Some of my environment variables are not showing up if I try to access them from in a makefile. wzi ciiloa tqjwr qrtsvbt owyiu rke kcma igxpq qhx wieaib febrvop hmzu jgfm kdur sydvfio