title: comparing two files based on a column and append elements in common to a file
body: <p>Basically I want to combine the power of <code>grepf</code> with <code>awk</code> or 'bash' commands. I have two files like this:</p>
  
  <pre><code>$file1
  ENSG00000000003 TSPAN6  ensembl_havana  TSPAN6
  ENSG00000000419 DPM1    ensembl_havana  DPM1
  ENSG00000000457 SCYL3   ensembl_havana  SCYL3
  ENSG00000000460 C1orf112    ensembl_havana  C1orf112
  ENSG00000000971 CFH ensembl_havana  CFH
  ENSG00000001036 FUCA2   ensembl_havana  FUCA2
  
  $file2
  ENSG00000000003.12  0.0730716237772557  -0.147970450702234
  ENSG00000000419.5   0.156405616866614   -0.0398488625782745
  ENSG00000000457.3   -0.110396121325736  -0.0147093758392248
  ENSG00000000460.15  -0.0457144601264149 0.322340330477282
  ENSG00000000971.12  0.0613967504891434  -0.0198254029339757
  ENSG00000001036.4   0.00879628204710496 0.0560438506950908
  </code></pre>
  
  <p>And here my desired output</p>
  
  <pre><code>ENSG00000000003.12  TSPAN6  0.0730716237772557  -0.147970450702234
  ENSG00000000419.5   DPM1    0.156405616866614   -0.0398488625782745 
  ENSG00000000457.3   SCYL3   -0.110396121325736  -0.0147093758392248 
  ENSG00000000460.15  C1orf112    -0.0457144601264149 0.322340330477282   
  ENSG00000000971.12  CFH 0.0613967504891434  -0.0198254029339757 
  ENSG00000001036.4   FUCA2   0.00879628204710496 0.0560438506950908  
  </code></pre>
  
  <p>This output also will be useful</p>
  
  <pre><code>ENSG00000000003 TSPAN6  0.0730716237772557  -0.147970450702234
  ENSG00000000419 DPM1    0.156405616866614   -0.0398488625782745 
  ENSG00000000457 SCYL3   -0.110396121325736  -0.0147093758392248 
  ENSG00000000460 C1orf112    -0.0457144601264149 0.322340330477282   
  ENSG00000000971 CFH 0.0613967504891434  -0.0198254029339757 
  ENSG00000001036 FUCA2   0.00879628204710496 0.0560438506950908
  </code></pre>
  
  <p>I have tried the command from <a href="https://stackoverflow.com/questions/14470879/obtain-patterns-from-a-file-compare-to-a-column-of-another-file-print-matching">Obtain patterns from a file, compare to a column of another file, print matching lines, using awk</a></p>
  
  <pre><code>awk 'NR==FNR{a[$0]=1;next} {n=0;for(i in a){if($0~i){print; break}}} n' file2 file 
  </code></pre>
  
  <p>But obviously it does not give me the desired output</p>
  
  <p>Thanks</p>