bash - Extract lines in file1 starting with a specific word given in file2 -

i have 1 file "file1" contains lines like:

643 2   3   4   5 6433    2   3   4   5 64  2   3   4   5 1234    2   3   4   5 1240    2   3   4   5 12  2   3   4   5

and extract lines first word contained in file 2, like:

12 64

thus, final result should be:

12  2   3   4   5 64  2   3   4   5

in bash think have use loop examining each word in file 2, not know command extract line in file1 containing exact word.

for example, using:

sed -n '/^64/p' file1

i get:

643 2 3 4 5 6433 2 3 4 5 64 2 3 4 5

which not correct, because line: 64 2 3 4 5

do know bash method (sed, grep, awk, or python if prefer) it?

you can use:

awk 'nr==fnr{a[$1]; next} $1 in a' file2 file1 64  2   3   4   5 12  2   3   4   5

Braziel