## Basics
* Reverse: `sort -r`
* Random: `sort -R`

## Sorting by field
We specify field by the `-k` option.
```
sort -k2 <file>
```
but this will do a *lex order* sort on that field. If we want a numerical sort:
```
sort -n k2 <file>    # or
sort -g k2 <file>
```
the first, `sort -n` sorts integers, the second sorts floats and `1.3e4` too.
Consider the input
```
hello 1 flibble
hello 2 flibble
hello 10 flibble
hello 13 flibble
hello 21 flibble
hello 21.1 flibble
hello 21.2 flibble
hello 22 flibble
hello 2.21e1 flibble
hello 23 flibble
```
then `sort -k2` will output
```
hello 1 flibble
hello 10 flibble
hello 13 flibble
hello 2 flibble
hello 2.21e1 flibble
hello 21 flibble
hello 21.1 flibble
hello 21.2 flibble
hello 22 flibble
hello 23 flibble
```
and `sort -k2 -n` will output (note how `2.21e1` lies between 2 and 10)
```
hello 1 flibble
hello 2 flibble
hello 2.21e1 flibble
hello 10 flibble
hello 13 flibble
hello 21 flibble
hello 21.1 flibble
hello 21.2 flibble
hello 22 flibble
hello 23 flibble
```
and `sort -k2 -g` will output (now `2.21e1 == 22.11` is in the correct place)
```
hello 1 flibble
hello 2 flibble
hello 10 flibble
hello 13 flibble
hello 21 flibble
hello 21.1 flibble
hello 21.2 flibble
hello 22 flibble
hello 2.21e1 flibble
hello 23 flibble
```