compare 2 files and print the common content of file1 1

[jdhahbi]

Hi
I would like lines from file1 that are common to file2 as in the following example:

cat file1
22	A	alp	19	gtein	
255	B	macr	12	pring	
3	C	lin	12	pseue	
90	D	N-ace	8	1

cat file2
B
D

cat outfile
255	B	macr	12	pring	
90	D	N-ace	8	1

thank you for your help

 

[p5wizard]

With awk, you'll need to put file2 in an array and then print records from file1 if field 2 is on that array.

That's easier if you process file2 first, then file1. Google around for "awk array". Chances are you'll get yourself right back in this forum ;-).

But there's a neat solution with the UNIX join command:

join -1 2 -2 1 file1 file2

Only glitch is that the output field separator is (by default) one space character. But if you can live with that...

HTH,

p5wizard

 

[jdhahbi]

thank you for your help.
Joseph

 

[mikrom]

I'm trying to learn awk, so I done it as exercise
join.awk

[COLOR=#0000ff]# Run:[/color]
[COLOR=#0000ff]# awk -f join.awk file1.txt file2.txt[/color]
[COLOR=#6a5acd]BEGIN[/color] {
  [COLOR=#6a5acd]FS[/color] = [COLOR=#ff00ff]" "[/color]
  lines_found = [COLOR=#ff00ff]0[/color]
}
{ 
  [COLOR=#804040][b]if[/b][/color] ([COLOR=#6a5acd]FILENAME[/color] == [COLOR=#6a5acd]ARGV[/color][[COLOR=#6a5acd]1[/color]]) {
    [COLOR=#0000ff]# mark line from 1.file in array[/color]
    line_array[[COLOR=#6a5acd]$1[/color]] = [COLOR=#ff00ff]1[/color]
  }
  [COLOR=#804040][b]if[/b][/color] ([COLOR=#6a5acd]FILENAME[/color] == [COLOR=#6a5acd]ARGV[/color][[COLOR=#6a5acd]2[/color]]) {
    [COLOR=#0000ff]# print adequate lines from 2.file[/color]
    [COLOR=#804040][b]if[/b][/color] (line_array[[COLOR=#6a5acd]$2[/color]]) {
      [COLOR=#804040][b]print[/b][/color] [COLOR=#6a5acd]$0[/color]
      lines_found ++
    }
  }
}
[COLOR=#6a5acd]END[/color] {
  [COLOR=#804040][b]printf[/b][/color] [COLOR=#ff00ff]"There were [/color][COLOR=#6a5acd]%d[/color][COLOR=#ff00ff] lines found and printed.[/color][COLOR=#6a5acd]\n[/color][COLOR=#ff00ff]"[/color][COLOR=#6a5acd],[/color] lines_found
}

Output:

$ awk -f join.awk file1.txt file2.txt
255    B    macr    12    pring    
90    D    N-ace    8    1
There were 2 lines found and printed.

I changed the file order i.e.
file1.txt

B
D

file2.txt

22    A    alp    19    gtein    
255    B    macr    12    pring    
3    C    lin    12    pseue    
90    D    N-ace    8    1