Reuse percent sign in Makefile prerequesite as subdirectory name

Question

I'd like to learn how to re-use the % sign in my makefile target's prequisite, supposing that the target is `X.pdf`, and the prerequesite is in `X/X.tex`. To elaborate, I currently have a makefile like so: ``` all: foo.pdf %.pdf: %.tex pdflatex $*.tex ``` I additionally have a file `foo.tex`, and when I type `make` it will make `foo.pdf` by running `pdflatex foo.tex`. Now for various reasons I can't control, my directory structure has changed: ``` my_dir |- Makefile |- foo |- foo.tex ``` I'd like to modify my Makefile such that when it tries to make `X.pdf`, it looks for the file `X/X.tex`. I tried the following (I tried to put '%/%.tex' to tell it to look for `foo/foo.tex`): ``` all: foo.pdf %.pdf: %/%.tex pdflatex $*/$*.tex ``` However, this yields: ``` No rule to make target `foo.pdf', needed by `all'. Stop. ``` So does `%.pdf: $*/$*.tex`. If I change the `%/%.tex` to `foo/%.tex` it works as expected, but I don't want to hard-code the `foo` in there, because in the future I'll do `…

Accepted Answer

you can use VPATH to specify a list of directories that make should search.

exemplary makefile:

```
# Find all tex files
tex := $(shell find -iname '*.tex')

# Make targets out of them
PDFS := $(notdir $(tex:%.tex=%.pdf))
# specify search folder
VPATH := $(dir $(tex))

all : $(PDFS)

%.pdf : %.tex
        pdflatex $<
```

or even better would be to use vpath (lowercase):

```
vpath %.tex $(dir $(tex))
```

it will look only for .tex files in those directories.

Reuse percent sign in Makefile prerequesite as subdirectory name

Solution

Problem