Question

I have two files. I would like to print the names which are in both files.

file1   

  1dfg   
  4rte
  aabd 
  hjgf

file2

  4rte
  2fgh
  1dfg

desired output

1dfg
4rte

Answer 1

grep can do that:

grep -f file2 file1

Results:

1dfg   
4rte

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However, awk may be more appropriate depending on the significance of whitespace:

awk 'FNR==NR { a[$0]; next } $0 in a' file2 file1

or:

awk 'FNR==NR { a[$1]; next } $1 in a' file2 file1