Sorting lines in one file given the order in another file

Question

Given a file1:

13 a b c d
5 f a c d
7 d c g a
14 a v s d

and a file2:

7 x
5 c
14 a
13 i

I would like to sort

Answer 1

Simple solution

for S in $(cat file2 | awk '{print $1}'); do grep $S file1; done

Answer 2

Use awk to put the line number from file2 as an extra column in front of file1. Sort the result by that column. Then remove that prefix column

awk 'FNR == NR { lineno[$1] = NR; next}
     {print lineno[$1], $0;}' file2 file1 | sort -k 1,1n | cut -d' ' -f2-