Can i specify the sort rule when sort an table

[malongshuai]

Question

for example, i want to sort the result of ls command by the filename length.

~> ls
╭───┬─────────────────────┬──────┬─────────┬──────────────╮
│ # │        name         │ type │  size   │   modified   │
├───┼─────────────────────┼──────┼─────────┼──────────────┤
│ 0 │ dump.rdb            │ file │   975 B │ 3 weeks ago  │
│ 1 │ redis-stable        │ dir  │ 4.0 KiB │ 3 months ago │
│ 2 │ redis-stable.tar.gz │ file │ 3.3 MiB │ 3 months ago │
╰───┴─────────────────────┴──────┴─────────┴──────────────╯

i checked the document: sort-by(https://www.nushell.sh/commands/docs/sort-by.html), i think it can accept a closure to sort by any rule. like this:

ls | sort-by {|row| $row.name | length}

Additional context and details

No response

[woosaaahh]

Hi !

The only parameters that sort-by accept are the column names.

It's not mentioned in the documentation but those parameters must be string.
See the line here https://github.com/nushell/nushell/blob/main/crates/nu-command/src/filters/sort_by.rs#L81
The let columns: Vec<String> part can be understood as "columns will be a vector (kind of array) of strings".

To solve your problem, you can use a temporary column and sort-by it.

ls | insert name_len { get name | str length } | sort-by name_len | reject name_len

> [[name]; [a] [bcd] [ef]]
╭───┬──────╮
│ # │ name │
├───┼──────┤
│ 0 │ a    │
│ 1 │ bcd  │
│ 2 │ ef   │
╰───┴──────╯

> [[name]; [a] [bcd] [ef]]
::: | insert name_len { get name | str length }
::: | sort-by name_len
::: | reject name_len
╭───┬──────╮
│ # │ name │
├───┼──────┤
│ 0 │ a    │
│ 1 │ ef   │
│ 2 │ bcd  │
╰───┴──────╯