<p>How do I <code>grep</code> and show the preceding and following 5 lines surrounding each matched line?</p>

For
BSD
or
GNU
```
grep
```
you can use
```
-B num
```
to set how many lines before the match and
```
-A num
```
for the number of lines after the match.
```
```
grep -B 3 -A 2 foo README.txt
```
```
If you want the same number of lines before and after you can use
```
-C num
```
.
```
```
grep -C 3 foo README.txt
```
```
This will show 3 lines before and 3 lines after.