Makefile variable not set from grep output -

i trying set variable cogline output of grep line (which searching config.json file regexthe "cogs"). when execute grep line correctly outputs proper line number, when echo variable comes blank.

cogline = $(grep -n \"cogs\" ~/desktop/repos/pronghorn/config.json | cut -f1 -d:)  all:     grep -n \"cogs\" ~/desktop/repos/pronghorn/config.json | cut -f1 -d:     echo $(cogline) 

here output:

glennmbp:test glenn$ make grep -n \"cogs\" ~/desktop/repos/pronghorn/config.json | cut -f1 -d: 2 echo  

you can see line number found "2", variable comes blank if not set. doing wrong?

grep not make function. cogline = line make assignment.

you either need use

cogline := $(shell grep -n \"cogs\" ~/desktop/repos/pronghorn/config.json | cut -f1 -d:) 

if want run @ make parse time , want in make variable.

or

all:         cogline=$$(grep -n \"cogs\" ~/desktop/repos/pronghorn/config.json | cut -f1 -d:); \         echo "$${cogline}" 

to run @ all recipe execution time , have in shell variable.

there middle grounds 2 basic ideas.