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makefilegrepcut

gnu makefile grep, flush variable to right side

I have a variable in a textfile that could look like these three alternatives (1-3 chars):

variable=XXX
variable=V3
variable=U

In my makefile, I read this variable in with grep

VAR=$(shell grep -w "variable=" textfile.txt | cut -c 10-13)

Question:

But I want to to have this variable VAR "right-handed" which means that if variable=U then VAR[0]="", VAR[1]="", VAR[2]="U".

Solution

  • Assuming you have printf available you could simply use...

    VAR=$(shell printf '%3s' `grep -w "variable=" textfile.txt | cut -c 10-13`)