使用grep -f从另一个文件获取确切的行数

Question

I have a file 1 that looks like this:

rs1
rs1
rs2
rs11

And file 2 like this:

rs1 100
rs2 200
rs11 300
rs21 400

I want to get the exact match of file 1 in file 2 (that is the exact number of lines). My desired output:

rs1 100
rs1 100
rs2 200
rs11 300

But I am getting this:

rs1 100
rs2 200
rs11 300

This is the command I am using:

grep -w -f file1 file2 

Also tried this:

grep '^rs\w\+$' file1 | sed 's/^/^/;s/$/\ /' | grep -f - file2

Thank you in advance.

Answer 1

Have you tried join

$join file1 file2
rs1 100
rs1 100
rs2 200
rs11 300

From man join

  join - join lines of two files on a common field
         For  each  pair of input lines with identical join fields, write a line
         to standard output.  The default join field is the first, delimited  by
         whitespace.

OR

using awk

$ awk 'FNR==NR{line[$1]=$0; next} ($0 in line){print line[$0]}' file2 file1
rs1 100
rs1 100
rs2 200
rs11 300