Makefile生成文件的数字列表

Question

I have a Makefile that I use for building a book I am writing into EPUB and Kindle formats.

However, my list of source files is getting really long:

CHAPTERS = \
    1.md \
    2.md \
    ...
    30.md \

I am trying to generate this list programmatically, and I got it working with:

CHAPTERS = $(addsuffix .md, $(shell seq 1 30))

But can't help but feel I feel like there is a simpler way.

Is there a simpler method to achieve numerical file generation (ie can this be reduced to a single command instead of 2 nested commands)?

Answer 1

Coincidentally, the GNUmake Table Toolkit features such a function:

$(call interval,start,range[,step])

$(call interval,5,5) --> 5 6 7 8 9
$(call interval,2,3,100) --> 2 102 202

Of course, simple is just a relative measure...

Answer 2

Is there a simpler method to achieve numerical file generation

You can do without shell. Whether it's simpler or not...

mygen=$(words $3)$1 $(if $(word $2,$3),,$(call mygen,$1,$2,w $3))
CHAPTERS:=$(call mygen,.md,30,w)