Makefile directive interpretation











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I am trying to reverse this Makefile.



However in the folowing lines:



install-packer: tmp/packer_$(PACKER_VERSION).zip

    mkdir -p ~/bin

    unzip -o -d ~/bin $<

    chmod +x $(PACKER)

    @echo Packer $(PACKER_VERSION) was successfully installed!



# Install packer only if it doesn't exist

$(PACKER):

    @$(MAKE) install-packer



tmp/packer_$(PACKER_VERSION).zip:

    curl -fsSLo $@ 'https://releases.hashicorp.com/packer/$(PACKER_VERSION)/packer_$(PACKER_VERSION)_$(UNAME)_amd64.zip'

    @echo Downloaded new Packer version: $(PACKER_VERSION)!


I am unable to understand the following directive/dependency:



# Install packer only if it doesn't exist

$(PACKER):

    @$(MAKE) install-packer


How it will




install packer only if it doesn't exist




?






makefile







share|improve this question


























    up vote
    0
    down vote

    favorite












    I am trying to reverse this Makefile.



    However in the folowing lines:



    install-packer: tmp/packer_$(PACKER_VERSION).zip
    
    mkdir -p ~/bin
    
    unzip -o -d ~/bin $<
    
    chmod +x $(PACKER)
    
    @echo Packer $(PACKER_VERSION) was successfully installed!
    

    
# Install packer only if it doesn't exist
    
$(PACKER):
    
    @$(MAKE) install-packer
    

    
tmp/packer_$(PACKER_VERSION).zip:
    
    curl -fsSLo $@ 'https://releases.hashicorp.com/packer/$(PACKER_VERSION)/packer_$(PACKER_VERSION)_$(UNAME)_amd64.zip'
    
    @echo Downloaded new Packer version: $(PACKER_VERSION)!


    I am unable to understand the following directive/dependency:



    # Install packer only if it doesn't exist
    
$(PACKER):
    
    @$(MAKE) install-packer


    How it will




    install packer only if it doesn't exist




    ?






    makefile







    share|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      I am trying to reverse this Makefile.



      However in the folowing lines:



      install-packer: tmp/packer_$(PACKER_VERSION).zip
      
    mkdir -p ~/bin
      
    unzip -o -d ~/bin $<
      
    chmod +x $(PACKER)
      
    @echo Packer $(PACKER_VERSION) was successfully installed!
      

      
# Install packer only if it doesn't exist
      
$(PACKER):
      
    @$(MAKE) install-packer
      

      
tmp/packer_$(PACKER_VERSION).zip:
      
    curl -fsSLo $@ 'https://releases.hashicorp.com/packer/$(PACKER_VERSION)/packer_$(PACKER_VERSION)_$(UNAME)_amd64.zip'
      
    @echo Downloaded new Packer version: $(PACKER_VERSION)!


      I am unable to understand the following directive/dependency:



      # Install packer only if it doesn't exist
      
$(PACKER):
      
    @$(MAKE) install-packer


      How it will




      install packer only if it doesn't exist




      ?






      makefile







      share|improve this question













      I am trying to reverse this Makefile.



      However in the folowing lines:



      install-packer: tmp/packer_$(PACKER_VERSION).zip
      
    mkdir -p ~/bin
      
    unzip -o -d ~/bin $<
      
    chmod +x $(PACKER)
      
    @echo Packer $(PACKER_VERSION) was successfully installed!
      

      
# Install packer only if it doesn't exist
      
$(PACKER):
      
    @$(MAKE) install-packer
      

      
tmp/packer_$(PACKER_VERSION).zip:
      
    curl -fsSLo $@ 'https://releases.hashicorp.com/packer/$(PACKER_VERSION)/packer_$(PACKER_VERSION)_$(UNAME)_amd64.zip'
      
    @echo Downloaded new Packer version: $(PACKER_VERSION)!


      I am unable to understand the following directive/dependency:



      # Install packer only if it doesn't exist
      
$(PACKER):
      
    @$(MAKE) install-packer


      How it will




      install packer only if it doesn't exist




      ?






      makefile




      makefile






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked 15 hours ago









      pkaramol

      1033




      1033



























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