# find lines that matches on 2 different sorted file

Supposed we have 2 sorted files:

file1 

```
1
2
3
4
5
```

file2

```
3
4
5
6
7
```

`comm` is a utility for finding lines that appear (or not) between 2 files. The normal output are 3 column. 

1. Lines that is unique on file 1
2. Lines that is unique on file 2
3. Lines that are appear on both

### Examples

```bash
$ comm  file1 file2
1
2
		3
		4
		5
	6
	7
```

#### Find lines that on both file only

```bash
$ comm -12 file1 file2
3
4
5
```

`-12` supresses (do not include) colunm 1 & 2

#### Fine line that is unique on first file

```bash
$ comm -23 file1 file2
1
2
```

#### For file that is not uniq or sorted

If file is not sorted, you can use the `<(..)` operator

```bash
$ comm <(sort -u file1) <(sort -u file2)
1
2
		3
		4
		5
	6
	7
```