Makefile environment variables. Improve this question.
Makefile environment variables. So you can just write, e.
Makefile environment variables Inian. Makefiles contain five kinds of things: explicit rules, implicit rules, variable definitions, directives, and comments. In the generated Makefile I want to have something like: ifndef SOURCECODEPATH SOURCECODEPATH := /home/root/source_code_path endif It Checking environment variable in make through automake. How to use environment variables defined inside a makefile? Hot Network Questions Can one appeal to helpfulness when asking a tween to do chores? How could an Alcubierre/Warp Drive work in my science-fantasy story? On a light aircraft, should I turn off the anti-collision light (beacon/strobe VERSION_ID=<value> so the shell command in the Makefile returns the string VERSION_ID=<value>, then the eval command acts on this to set the Makefile variable VERSION_ID. o’. That means that the value of the DB_NAME variable will be "spring-boot-todo" (including the quotes) not spring-boot-todo (without the quotes) as probably intended. It's equivalent to running the following from your shell: bash -c '. In python, you can print(os. /. I know similar thing is possible in ant and Jenkins but not sure how can I achieve same using makefile. It lists the other files that the targets depend on, called the prerequisites of Not sure if this is possible in one Makefile alone, but I was hoping to write a Makefile in a way such that trying to build any target in the file auto-magically detects the number of processors on the current system and builds the target in parallel for the number of processors. . Every environment variable that make sees when it starts up is transformed into a make variable with the same Environment Variables. Only doing echo $(BLAH) is merely evaluating Makefile's key/value mechanism inside the Makefile. How to stop GNU make from expanding dollar signs in MAKEFILE_LIST? 6. (If the What I usually do is not go using -d as previous answerers said. Viewed 8k times 4 . Hot Network Questions Lazy Set VARIABLE = value Normal setting of a variable, but any other variables mentioned with the value field are recursively expanded with their value at the point at which the variable is used, not the one it had when it was declared. In general it's wrong / a bad idea to use shell in a recipe. Per Wikipedia, . Make has several predefined variables among which is CC. Presumably /bin/sh doesn't support the SECONDS variable. make linux unix. Environment variable escaping across multiple That's not an answer to the question how to set a Makefile variable if it isn't set. How to export environment variables in Makefile. env syntax is not a subset of the Makefile syntax because there are certain symbols allowed in . 6 Also: $ readlink -f `which c++` /usr/bin/g++-4. Try this: make CFLAGS=-fomit-frame-pointer One word of warning. Any help is appreciated. Initially, it is set at cc which is a symlink to the installed C compiler: $ readlink -f `which cc` /usr/bin/gcc-4. The macro is defined as the collection of all input flag arguments into a string (without We also have variable defined in the make files and these can be accessed in the csproj as well. See "Using Environment Variables" for 9. 4 and above), you will see exported variables passed to shell. getenv("MURDOC")) to truly query the environment variable. How do I stop this being intrepreted as an escape character? defines a variable named objects to contain the value ‘main. Environment variable name: TEST, its value: "TRUE" test_target: ifeq ($(TEST),"TRUE") echo "Do something" endif I get the following error: As you noticed, these are Makefile {macros or variables}, not compiler options. Second, I'm not sure what magic you're attributing to the include operation but all this does is import the content of the file exactly as if you'd typed it into the first makefile. I have a simple Makefile: app : app. Improve this question. Ask Question Asked 5 years, 1 month ago. env URI := $( HOSTNAME ) : $( PORT ) The environment variables are then accessible using the $(VAR_NAME) syntax. I don't think that's a problem. txt without any success. This appendix summarizes the directives, text manipulation functions, and special variables which GNU make understands. For example the Makefile: set the environment variables output by a command. In this case, I have a dependency to mbedtls library which is downloaded and built in my cmake. Stop. 5. such as a Makefile, to configure the build or tests differently to run them inside of Jenkins. The real power of make variables starts to show when you pair them with environment variables. See Special Built-in Target Names, Catalogue of Built-In Rules, and Summary of Options, for other summaries. in your directory where the Makefile is installed; from now running make will use your environment variables; I used this to test. Answering the Question as Written: Because automake wants to generate Makefiles that work on POSIX make, it doesn't work too well with GNU-make conditionals. – MadScientist How to get environment variables from a file into Makefile > $ techctl. preventing variable expansion in makefile. Makefile: set the environment variables output by a command. cpp -o app but my application demands that var environment variable is set (var := "/etc/file. How to use environment variables defined inside a makefile? Hot Network Questions Is there a term for a solo break without the rest of the band stopping? What factors determine the frame rate in game programming? I have a file Makefile. If you use GNU make, you can use the export directive. I'm working on a go project which has a Makefile like below. Makefile: process colon-separated environment variables. env file in your directory and put your variables there; install and setup direnv for your shell configure it to allow . How to Check Whether a Variable Used in a Target Defined in an Each line in a makefile target's recipe runs in an independent environment. Most Makefiles don't expect their variables to be overridden. A variable is a name defined in a makefile to represent a string of text, called the variable’s value. PORT=3000. I know that these are set as the references come out correctly and everything compiles, but if I try and use one of these variables in the I'd like to set the default target(s) of a Makefile to the space-deliminted value of an Environment Variable. PHONY: deploy hello deploy: rsync . Finally we I am trying to figure out how to use env variables in makefiles. So instead of setting CC, CFLAGS, LDFLAGS, LD every time, I want to write a script which can set the Variables from the Environment. set CONFIGOR_ENV=local echo %CONFIGOR_ENV% ECHO 处于关闭状态。 then i got it **It's not possible for a makefile to set up your environment. You can add a line to your Makefile similar to the following: NUMJOBS=${NUMJOBS:-" -j4 "} Then add a ${NUMJOBS} line in your rules, or add it into another Makefile var (like MAKEFLAGS). I have a make file and I am trying to use it to copy files to a directory. As an alternative, what I have done is that I have split things up into two makefiles (created a sub-make) and declared the VARIABLE at the top of the sub-make and it now works like a charm. You can tell make to use a different shell by assigning a value to the SHELL variable (i. 2 Communicating Variables to a Sub-makeVariable values of the top-level make can be passed to the sub-make through the environment by explicit request. env' bash -c 'echo ${abce}' Put both commands on the same line (or use \ to split a single logical line across multiple physical lines) so that $ make VAR1=hello Makefile:7: *** VAR1 is not defined. Jump to navigation. SHELL := /bin/bash). In addition, make processes each command line in a different shell, so your set -a, . Hot Network Questions Why won't my White Chocolate Ganache set in the freezer? Expectations of estimators print text between special characters on same line and remove starting I'm trying to get an environment variable passed from the shell into an executable when it gets compiled, and be able to access that variable. asked Aug 4, 2016 at 13:55. A makefile runs commands in a Makefile environment variable changes between recipes. 1 'error: variable has incomplete type' problem with linking. The best way I could think of is somehow make Jenkins export this as environment variable that is accessible within makefile when build is going on. cpp g++ -c app. Welcome. Jack Wilsdon Jack Wilsdon. I think it is easy but I'm just missing something. The target: 9. 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. If $(BAR) produces a dollar sign, that dollar sign is now just data inside FOO and won't be causing any more problems. So in your case it would be as if you wrote your makefile like this: 9. Precedence is a prime consideration in doing this properly. Makefile: all: echo "Hello ${FOO}" . See 6. If SQL_HOST and SQL_PASSWORD are variables defined earlier in your Makefile, (rather than environment variables) you need to write it like this: SQL_HOST=localhost SQL_PASSWORD=hunter2 sqlcmd: docker-compose run sqlcmd sqlcmd -S sqlserver -U "$(SQL_HOST)" -P "$(SQL_PASSWORD)" PS: Welcome to the site. Eg: Actually, I cannot put the VARIABLE definition above all: because PATH_TO_MY_DATA_FILE does not exist until some commands have been run in the all: target. The following describes make's interaction with the environment. When it is time to execute recipes to update a target, they are executed by invoking a new subshell for each line of the recipe Please note: this implies that setting shell variables and invoking shell commands such as cd that set a context local to each process will not affect the following lines in the recipe. To pass down, or export, a I'm trying to include a file that contains environment variable pairs into a Makefile so that they are available to the environment in which make is running. GNU Make ignores environment variables on windows . Windows cares a lot about file extensions so you'll have to name this file win. env_vars. You can tune or rename it to your taste. 85. That means that if the Makefile uses CFLAGS to specify -I for include files, -O2 for optimization, or other flags, you must add them to your CFLAGS override or the Variables from the Environment. Print timestamp in makefile. 10 Variables from the Environment. These are the same machines being used for development. use environment variable if set otherwise use default value in makefile. ac:. How to stop GNU make from interfering with filenames that contain dollar-signs? 0. How to use environment variables defined inside a makefile? 1. Get Environment Variables From a File into Makefile. However, if you try to explicitly go inside "test" folder and attempt to "make all", then you will have to explicitly set the environment variable, prior to it (which in previous case, is set in the top-level Makefile). env dummy-target: @echo $(SOME_ENV_VAR) If want to you pass all your environment variables into Sub-make you should export them: ENV To do that you need to use one long line or use the . Option 1. For Variables in make can come from the environment in which make is run. How can I re-use a variable containing a timestamp throughout a Makefile run. I either: Use -p to print the database, to see what rules have been created. Here is the code . This can obviously be tweaked for other OS's depending how the metadata is stored. Modified 5 years, 8 months ago. You must set it: SHELL = csh Then if you want to use the variable, you must do so in the same command that sets it, because each command operates in its own subshell. Creating environment variables with a script for make. For example the All variables from the environment are imported as make variables. As you might expect, setting environment variables per stage means they will only apply to the stage in which they’re defined. makefile set 3. 6 You can change it if you want. I want to specify Dollars in Makefile environment variables. ONESHELL feature of recent versions of make . How to conditional set up a Makefile variable by testing if a file exists. I haven't had much luck with this myself, but it might be possible to use -l rather than -j to automatically run as many jobs as are appropriate for the number of cores you have available. If you specify a value in this way, all ordinary assignments of the same variable in the makefile are ignored; we say they have been overridden by the command line argument. Some of my environment variables are not showing up if I try to access them from in a makefile. pass env variables in make command in makefile. Hot Network Questions Prevent pagebreak before longtable What's left of wine or vodka after the water and alcohol is boiled off? Like any process, make can’t modify the environment of an existing process, it can only control the environment which is passed to processes it starts. (Note that I need to check that the variables are actually defined when the makefile is run, as I need to include another makefle further down and the variables need to be set correctly by the time I Downside to this is that . These are used to point to the locations of referenced dlls, so that they can be different on dev and build machines. env file, which might look something like this. cfg"), how to do this in Makefile? I mean, how to make it that after I ran command make Makefile I wold be able to do this: I write a makefile to set a environment variables in windows,but it does not work. Is there anything that goes against conventions? (like CCFLAGSINT - should I just overwrite CCFLAGS instead? Or CXXFLAGS? FUD!) Makefile 内のコマンドに環境変数を渡す. If you want to use cd to affect the next The most basic rule of GNU Make and the environment is that any variable set in the environment when GNU Make is started will be available as a GNU Make macro inside the Makefile. Makefile conditional not respecting target-specific variables. env. But from there, you cannot set a variable that applies elsewhere in the Makefile. Environment variables are read and added to the macro definitions each time make executes. Follow edited Apr 11, 2018 at 14:36. Example: In our shell we can export an environment What's more, make implementations typically execute each line of a recipe in a separate shell, so you cannot expect to set a shell variable in one line of a recipe and read its value back in a separate line. The problem is when I run make the C:\Data from the environment variable is interpreted as C:Data. Whitespace around the variable name and immediately after the ‘=’ is ignored. The difference between the example below and those which use := is the := assignment happens once (when it is encountered) and for all. Checking environment variable in make through automake. bat or something like that. Classpath is a parameter in the Java Virtual Machine or the Java compiler that specifies the location of user-defined classes and packages. Each line of a make recipe is executed by a separate shell, so even if you source the file, the shell that sources it exits before the next line is evaluated. However, an explicit assignment in the makefile, or with a command argument, overrides the environment. So you can just write, e. If you instead, want the substitution to happen during the Setting environment variable in makefile and reading it from python script does not work [duplicate] Ask Question Asked 7 years, 9 months ago. Variables in make can come from the environment in which make is run. 1 What Makefiles Contain. Variables defined with ‘=’ are recursively expanded variables. For this solution to work correctly, it must be possible for me to set an environment variable, then run make and have the target, (or optionally space-delimited targets), contained in the environment variable be used as though they were passed as targets. load environment variables from a file in a makefile on windows. o utils. How do I structure the Makefile and C program to do that? Make will override the variables if you put them on the make command line. An argument that contains ‘=’ specifies the value of a variable: ‘v=x’ sets the value of the variable v to x. bat that runs the makefile. Here is a summary of the directives GNU make recognizes: . You can use make -p -f /dev/null to get a list of all implicit rules and variables. – Michael Irwin. Some environment variables are defined in Windows, like the path to some SDK. One minute read. When make is run in a shell, any environment Every environment variable that make sees when it starts up is transformed into a make variable with the same name and value. VARIABLES was modified in your makefile, the two most voted answers won't catch it. PHONY: all all: echo $(MYVAR) You can't do this with a makefile OR with a separate shell script. 6 Passing variable from makefile to docker compose file? Load 7 more related questions Show fewer related questions Also your SHELL environment variables are converted in to Makefile environment variables, so you can directly make use of them while creating your rules. That means that if the Makefile uses CFLAGS to specify -I for include files, -O2 for optimization, or other flags, you must add them to your CFLAGS override or the There is one problem with using this method: make doesn't parse quotes. Viewed 2k times 1 . a $(O) When I echo I can see MACHTYPE is x86_64-pc-linux-gnu. That said, we can include the appropriate environment file in To pass down, or export, a variable, make adds the variable and its value to the environment for running each line of the recipe. dev) where . $(ENV). define variable define variable = define If make exports the variables, you can use them right away (but note that changes to shell variables will not change the make variables). – It's also doable without saving all the . Related. Export environment variables from makefile to shell. Also the cd command failed because of non-existing path. environment variables cause make's undefine to fail (Windows) 1. sh | xargs) echo ${VAR1} #there is no variable here echo ${VAR2} #there is no variable here Where: this-script-generate-key-values. Hot Network Questions $ make VAR1=hello Makefile:7: *** VAR1 is not defined. Hot Network Questions What are the legitimate applications for entering dreams in variables defined in the Makefile; environment variable; There are an exception (-eflag): Variables in make can come from the environment in which make is run. 8. dev export $(shell sed 's/=. make_var = I am a make variable all: When Make starts, it automatically creates Make variables out of all the environment variables that The syntax to access the environment variable in make is like other variables in make #export the variable. env # Environment variables for project include By default make uses /bin/sh as the shell which executes recipe lines. Restrict environment variables to command when cross compiling Golang program on Windows. put a . Only in the very latest version of GNU make (4. In most versions of GNU make, variable exported from the makefile are passed to recipes but they are not passed to the shell function. If make does not export the variable, you can use the shell's one-shot assignment, like in. That said, we can include the appropriate environment file in our Makefile. Doing that will make SECONDS available but will still not allow you to carry a variable value between recipe lines as each recipe line is run in its Docs: "Be aware that a given prerequisite will only be built once per invocation of make, at most. 1 Passing Variables in Makefile. a: Permission denied which is supposed to be x86_64-pc Your question is unclear, so I will have to guess what you mean. However, an explicit assignment in the makefile, or with a The most basic rule of GNU Make and the environment is that any variable set in the environment when GNU Make is started will be available as a GNU Make macro inside the Makefile. The sub- make, in turn, uses the environment to initialize its 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. There are four ways to set the variables that control the Make process: Use environmental variables and call Make with the -e option: $ export MP_CC=/opt/microchip In my Makefile deploy target I create environment variables and I want to reuse those in the following lines: SHELL=/bin/sh deploy: export $(shell sh this-script-generate-key-values. However, if you try to explicitly go inside "test" folder and attempt to "make all", then you will have to explicitly set the environment variable, prior to it (which in previous I have makefile (GNUmake) in which I would like to use current release number for some operation. If the same file is a prerequisite of multiple targets, and each of those targets has a different value for the same target-specific variable, then the first target to be built will cause that prerequisite to be built and the prerequisite will inherit the target-specific value from the first The syntax to access the environment variable in make is like other variables in make #export the variable. Makefile for GoLang Cross Compilation. But when I type make, it says ar: /jkweb. Below is In GNU make, conditional parts are used e. However when I pass them to my make recipes they all show up empty. environment variable not set in makefile. This allows users of the makefile to more easily adapt the makefile to their specific environment. env, which make requires to be escaped. Variables defined with ‘:=’ or ‘::=’ are simply expanded variables; these definitions can contain variable references which will be expanded before the Environment Variables . o bar. These variables are defined in the sub-make as defaults, but they do not override variables defined in the makefile used by the sub-make unless you use the ‘-e’ switch (see Summary of Options). make --eval='print-tests: @echo TESTS $(TESTS) ' print-tests You can insert the required TAB character in the command line Make uses /bin/sh by default, but you can override this with the SHELL variable, which Make does not import from the environment. Note that the "release" target sets two environment variables so that the "build" target cross-compiles for a specific architecture (which With GNU Make, you can use shell and eval to store, run, and assign output from arbitrary command line invocations. Commented This will export all make variables as Note the differences between Makefile variables and Shell variables in this next example. I'm trying to pass an environment variable to an external project in my CMakeLists. . I want to modify and export "LD_LIBRARY_PATH" environment variable in order to link libjvm. env files, one for production and one for development. I have found some documentation but I am having a hard time seeing how to use it in my case. a: $(O) $(MACHTYPE) ar rcus $(MACHTYPE)/jkweb. Apart from standard set of targets, like clean, distcleant, install, etc, I also want to know if there are any naming conventions like what to use as a word separator, either a dash, underscore or nothing. However, makefiles on my newer Ubuntu system assign the Bug in this makefile: The bug that I see is the coder has used "cd $(ENV_VAR)" instead of "cd $$(ENV_VAR)". If PROCESSOR_ARCHITEW6432 isn't set, then fallback to checking PROCESSOR_ARCHITECTURE. like this. They implement a set of conventions. You only need origin if you want to behave differently depending on whether the variable was defined in the environment vs. The setenv command is part of the C shell, which is not the default for Make. $(MACHTYPE)/jkweb. variable in Makefile not recognized by make correctly. Rules, variables, and directives are described at length in later chapters. *//' . 1. It is very easy to achive that in make: # When it comes to loading environment variables in a Makefile most answers point to doing this: include . exe. The most common way to use this facility is to pass extra flags to compilers. The value function provides a way for you to use the value of a variable without having it expanded. So short of stuffing the input buffer, there’s no way to do what you’re trying to do. But an explicit assignment in the makefile, or with a command argument, overrides the environment. command is a feature of the POSIX shell. 20. This will use the NUMJOBS envvar, if it exists; if it doesn't, automatically use -j4. install. local: set CONFIGOR_ENV=local echo %CONFIGOR_ENV% then i exec it,it print. For instance, there are often several versions of awk on a Unfortunately, the problem is not with the makefile itself but with the variable being used. If you need to set variables in your Makefile that are visible across all targets, set make variables: As already correctly pointed out, there is no difference but be be wary not to mix the two kind of delimiters as it can lead to cryptic errors like in the GNU make example by unomadh. cfg"), how to do this in Makefile? I mean, how to make it that after I ran command make Makefile I wold be able to do this: An environment variable ENVAR that exists when you invoke nmake is inherited as an nmake macro of the same name. env: FOO=alex 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. In my case I want to make the below more general. The environment variables usually don't exist. Modified 7 years, 9 months ago. # Makefile include . – Roland Weber. This situation can cause some problems since the environment variables desired for deploys can be different from the ones to be used for development! Makefile: Set environment variable for future use as part of a build step. I am doing deploys from specific machines. Additionally, you are using $(NODE_ENV) in your recipe expecting that to be the shell Unfortunately, Makefile doesn’t automatically have access to the root . Ask Question Asked 5 years, 8 months ago. So ifdef works for environment variables as well. I cannot From here:. (In some other versions of make, variables are called macros. 6. am I am using to generate a Makefile. Modified 5 years, 1 month ago. exa Make will override the variables if you put them on the make command line. I have a Makefile target, in which I have to check the value of an environment variable. 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. – But nothing will make an environment variable set in a shell process in one target visible in another target, because there's no way to get these to execute in the same process. When you run make, or run a shell script, it creates a new process. sh generates this output: Assuming make is GNU Make, all the environment variable settings inherited by make are automatically registered as make variable settings. The path of the directory is stored in an environment variable. am and make sure a sensible value for it is set by configure. g. Any changes made to the environment of that process will all be tossed away when that process exits. This solution relies on GNU make's verbatim variables, which get exported to environment variables and are referenced with $$. In Linux this works as intended, however in a Windows environment, I need to pass a variable WINDOWS_BUILD=1 to the make environment. (Note that I need to check that the variables are actually defined when the makefile is run, as I need to include another makefle further down and the variables need to be set correctly by the time I environment variable not set in makefile. If you really mean to test an environment variable (as opposed to a make variable), then simply do so in the commands: If so, you might need to (cautiously!) run make -e to allow environment variables to override makefile variables – twalberg Commented Oct 23, 2015 at 19:11 Makefile: Reuse environment variables. 4. sh may fail on GitHub Actions, or in other environments where many machines share IP addresses. Unable to cleanly set GOOS environment variable on win7. 0 How to use environment variables defined inside a makefile? Load 7 more related questions Show fewer related questions Sorted by: Reset to default Know someone who can answer? Share a link to this question First, these are not environment variables. You are testing an environment variable in a shell command executed by make. I want to run it on Window or Linux as per the user need. Note that in Fedora there is not a default environment variable that gives the OS I couldn't find anything in the GNU Makefile Conventions. I suspect make is doing some odd parsing on the results. makefile set environment variables in window. I want to print this value using echo command in make files. Hot Network Questions Movie / TV show where main character has a metallic skull A kind of "weak reference" which keeps the object alive, as long as there is otherwise-unused memory Does launch on warning assume incoming ICBMs carry nuclear warheads? I looked at my makefiles again - so, makefiles on my old Windows XP system do refer to the MAKELIBHOME environment variable, which has been set (interactively) before. I've resorted to simply defaulting to 32-bit on makefile; environment-variables; Share. dev is a file containing my environment variables, for example: FOO=bar SQL_DATABASE=mydb_dev However, I have two . First, you can't name the file win. I already have the x86_64-pc-linux-gnu directory in the current directory. VARIABLES and filtering them out. Problem exporting environment variable in Makefile. Calculate makefile build time . env, and set +a lines are run in separate shells. But an explicit assignment in the makefile, or with a command # Makefile ENV:= $(PWD) /. This is my make file. 3. Say SDKPATH C:\MySDKPath for instance. Dollars in Makefile environment variables. Note that the "release" target sets two environment variables so that the "build" target cross-compiles for a specific architecture (which is possibly not that of the build system). Makefile - Function to check empty environment variables. Immediate Set VARIABLE := value Setting of a variable with simple expansion of the values inside - values within it are expanded at declaration time. Hot Network Questions What are the legitimate applications for entering dreams in 3. I also have an environment variable that I would like to use within the makefile. Setting environmental variables in Makefile. UNEXPORTED_VAR = foo all: I am using make's shell command to populate some variables, and on output it indicates that they are being set to the values I expect. You are not using a POSIX shell on Windows, you're using Windows cmd. Initially, it is set at cc which is a symlink to the installed C compiler: $ readlink -f `which cc` /usr/bin/gcc-4. A macro, MAKEFLAGS, is maintained by make. How to modfiy environment variable in GNU makefile. 5 Pass host environment variables during build in dockerfile. $(PWD)/. However, an explicit assignment in the makefile, or with a @JimB I think the problem is that the OP does not know that lines of a recipe are executed in different shells, not the relationships between make variables and environment variables. EDIT: To delay Lazy Set VARIABLE = value Normal setting of a variable, but any other variables mentioned with the value field are recursively expanded with their value at the point at which the variable is used, not the one it had when it was declared. To do that you need to use one long line or use the . They're make variables (or make macros). I have a makefile and a . This doesn't work. ONESHELL feature of recent versions of make. command line etc. makefile vs. Makefile: Set environment variable for future use as part of a build step. go The same thing as above, implemented as below in the make file works and my go code is able read the env variable. env files; run direnv allow . From the GNU make manual on the Function Call Syntax (emphasis mine):. Thanks @RolandWeber for your comment, It was just a code snippet however I I want to write platform independent Makefile's environment variable setup script which can set Makefile's environment variable like CC, CFLAGS, LDFLAGS, LD etc. Recursively expanded variables set with = are a bit more "lazy"; references to other variables remain until the variable I have a simple Makefile: app : app. So the export and assignment on the first line of the START target's recipe doesn't affect the second line. 3k 15 15 gold badges 160 160 silver badges 179 179 bronze badges. e. Variables in make can come from the environment in which make is run. Note that install. – Environment variables can be set globally, like the example below, or per stage. So because of this, we haven't actually used the overriden make variable for "cd" command instead still using the value of environment variable before executing $(MAKE). My application creates an environment variable MACHTYPE with a value say "DELLMACHINE". How to solve this? It appears that the MAKEFLAGS environment variable can pass flags that are part of every make run (at least for GNU make). Downside to this is that . My makefile has the following two lines. For example, say I wanted to build the time something was compiled into the application when it gets built so I can see when the executable was built. This may or may not matter depending on how the variables are used. 0. so with my code. 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. e. 2. sh calls GitHub APIs in order to determine the latest version of just to install, and those API calls are rate $ make VAR1=hello Makefile:7: *** VAR1 is not defined. Makefile は 長い コマンド等の手軽なコマンド化を行うのに便利です。 一方で、 Makefile 内では、複数行でコマンドを渡すと、1つ1つが別々なプロセスで扱われるなど、 bash に コマンドを1つ1つ実行するのとは違う挙動を示します。 C Makefile: How to build environment variable into executable. If you were prepared to assume that the variable's value did not contain any single quotes, then you could simply quote with that: I try to set the env variable explicitly by having 1 statement to set (export), the other to run my go code where I read the env variable. Makefiles can indeed reference environment variables, which is exactly what CLASSPATH is in this context. Please note that this does not undo expansions which have already occurred; for example if you create a simply expanded variable its value is expanded The . Tried hard, but can't find it. Moreover, if one of the original . These values are substituted by explicit request into targets, prerequisites, recipes, and other parts of the makefile. o foo. I am using this for defining a path variable to be Appendix A Quick Reference. set env variable from a Makefile command and use in another Make command. I suggest setting SHELL (in the Makefile) to whatever you're using in your environment and trying Assuming make is GNU Make, all the environment variable settings inherited by make are automatically registered as make variable settings. 5 Overriding Variables. AC_SUBST([JAVA_HOME]) In general it is a good idea to use variables to represent external programs. 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. Doing that will make SECONDS available but will still not allow you to carry a variable value between recipe lines as each recipe line is run in its Makefile: Set environment variable for future use as part of a build step. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Therefore, when the parent-Makefile, exports some variable, then for that build-environment, the exported variable will be visible to all the sub-directory Makefiles. 7. If I am right it is not a duplicate of the question you found (but it is probably a duplicate of another question). It lists the other files that the targets depend on, called the prerequisites of Therefore, when the parent-Makefile, exports some variable, then for that build-environment, the exported variable will be visible to all the sub-directory Makefiles. But, I don't get the exact syntax of it. This question already has an answer here: but I'm having problems with setting environment variables, when I run make integration, the TYPE environment variable would not be set, if I set the environment variable manually with export TYPE=integration, then I run make unittest, the environment variable would not be unset. ifeq ($(CC),gcc) $(CC) -o foo $(objects) $(libs_for_gcc) else $(CC) -o foo $(objects) $(normal_libs) endif The GNU make manual has all the details. Export environment variable in Makefile. GNU Make ignores environment variables on windows. 2021-03-04. Within the Makefile, I am using this path to access the SDK's include directory, among other things: CFLAGS := -I$(SDKPATH)/include I'm working on a go project which has a Makefile like below. If the arguments themselves contain other function calls or variable references, it is wisest to use the same kind By default make uses /bin/sh as the shell which executes recipe lines. exe you just run the script; it doesn't start a new command program I have makefile (GNUmake) in which I would like to use current release number for some operation. That expansion is done when FOO is assigned because I used an immediate variable (:=). @echo $(MACHTYPE) Upon executing the above command empty string is getting displayed. So you do the test in configure. Makefile (1) ifdef myvar MYVAR := $(myvar) else MYVAR := default endif . A Makefile deploy recipe needs an environment variable ENV to be set to properly execute itself, whereas other recipes don't care, e. test: export Sample="Help" go run main. More In the manual for GNU make, they talk about this specific example when describing the value function:. (Note that I need to check that the variables are actually defined when the makefile is run, as I need to include another makefle further down and the variables need to be set correctly by the time I Export environment variables from makefile to shell. Hot Network Questions What's left of wine or vodka after the water and alcohol is boiled off? Ranks for an Asymmetric Independent Variable Elegant way to maximizing linear function subject to being on the surface of a sphere LitRPG on Royal Road with a reviving girl dumped into a I'm trying to get an environment variable passed from the shell into an executable when it gets compiled, and be able to access that variable. ) If the solution of deciding within the makefile which one of several linker scripts is not sufficient, then generating the script within make might be a viable option. This is handy if you have second expansion rules and are creating rules on the fly, especially recursive make. This target filters out and prints all the variables that were defined in a makefile: Variables from the Environment. Login; Join; Member Benefits; Sort I am trying to write some Makefile for a project to be compiled with GNU make under Cygwin. Viewed 4k times 3 . Check out $(origin) function. If want to you pass all your environment variables into Sub-make you should export them: # Makefile ENV:= $(PWD) /. PHONY: all all: echo $(MYVAR) What I think's the right way: Rely on $(JAVA_HOME) being set in Makefile. If I have FOO := $(BAR), and then somewhere I'm interpolating $(FOO) into a shell script, I want $(BAR) to be expanded. , ENV = . Makefile environment variable for specific target. However, when I run it prints an 6 How to Use Variables. I haven't found a variable that returns the actual operating system's architecture, and this particular one simply returns the architecture make was compiled for, as the variable is being called from make. An explicit rule says when and how to remake one or more files, called the rule’s targets. It's totally unnecessary because a recipe is already running in a shell. Commented Jun 7, 2019 at 12:37. Any ideas why this doesn't work? What can I do to make this work? Thanks in advance. Every environment variable that make sees when it starts up is transformed into a make variable with the same name and value. Second, in Windows cmd. env # Environment variables for project include $(ENV) # Export all variable to sub-make export You can now access your env vars in make targets: include . (Macros is an old name for them, still used by some. wyyqrznssqpkrtmekfjtyjtlcpanwfpszkelugksfclkorqeklw