Is it possible to create a multi-line string variable in a Makefile

by

Yes, you can use the define keyword to declare a multi-line variable, like this:

define ANNOUNCE_BODY
Version $(VERSION) of $(PACKAGE_NAME) has been released.

It can be downloaded from $(DOWNLOAD_URL).

etc, etc.
endef

The tricky part is getting your multi-line variable back out of the makefile. If you just do the obvious thing of using “echo $(ANNOUNCE_BODY)”, you’ll see the result that others have posted here — the shell tries to handle the second and subsequent lines of the variable as commands themselves.

However, you can export the variable value as-is to the shell as an environment variable, and then reference it from the shell as an environment variable (NOT a make variable). For example:

export ANNOUNCE_BODY
all:
    @echo "$$ANNOUNCE_BODY"

Note the use of $$ANNOUNCE_BODY, indicating a shell environment variable reference, rather than $(ANNOUNCE_BODY), which would be a regular make variable reference. Also be sure to use quotes around your variable reference, to make sure that the newlines aren’t interpreted by the shell itself.

Of course, this particular trick may be platform and shell sensitive. I tested it on Ubuntu Linux with GNU bash 3.2.13; YMMV.

More Related Contents:

  1. How to get variable name?
  2. Creating or referencing variables dynamically in Sass
  3. What’s the difference between placing “mut” before a variable name and after the “:”?
  4. Error if don’t check if {{object.field}} exists
  5. When should an Excel VBA variable be killed or set to Nothing?
  6. When should I quote CMake variables?
  7. HiveQL: Using query results as variables
  8. Dynamically create variables in PowerShell
  9. In Rust, what’s the difference between “shadowing” and “mutability”?
  10. setq and defvar in Lisp
  11. What is the difference between a member variable and a local variable?
  12. LessCss dynamic variables based on ancestor class
  13. Powershell pass variable to start-job
  14. How to make points one color when a third column equals zero, and another color otherwise, in Gnuplot?
  15. Batch File Set Variable not working [duplicate]
  16. In MATLAB, are variables REALLY double-precision by default?
  17. Comparing IEEE floats and doubles for equality
  18. Multiple variable assignment in Swift
  19. Dynamic Variable Naming and Reference (ColdFusion)
  20. Windows Batch files: what is variable expansion, and what does EnableDelayedExpansion mean?
  21. What is the difference between a constant and a static variable and which should I choose?
  22. gnuplot store one number from data file into variable
  23. What is the order of local variables on the stack?
  24. What is “_,” (underscore comma) in a Go declaration?
  25. Set fact with dynamic key name in ansible
  26. Declaring global variable with php.ini
  27. Why does Go allow compilation of unused function parameters?
  28. Create a variable in swift with dynamic name
  29. Finding out reason of Pyomo model infeasibility
  30. When should I quote CMake variable references?

Leave a Comment