---
title: Parsing
---
# Parsing
*Nu* offers the ability to do some basic parsing, with different ways to achieve the same goal.
Builtin-functions that can be used include:
- `lines`
- `detect columns`
- `parse`
- `str ...`
- `from ssv`
A few illustrative examples follow.
## Examples (tabular output)
### `detect columns` (pretty automatic)
```nu
df -h | str replace "Mounted on" Mounted_On | detect columns
# => ╭────┬───────────────────────────────────┬──────┬──────┬───────┬──────┬────────────────────────────────────╮
# => │ # │ Filesystem │ Size │ Used │ Avail │ Use% │ Mounted_On │
# => ├────┼───────────────────────────────────┼──────┼──────┼───────┼──────┼────────────────────────────────────┤
# => │ 0 │ devtmpfs │ 3.2G │ 0 │ 3.2G │ 0% │ /dev │
# => │ 1 │ tmpfs │ 32G │ 304M │ 32G │ 1% │ /dev/shm │
# => │ 2 │ tmpfs │ 16G │ 11M │ 16G │ 1% │ /run │
# => │ 3 │ tmpfs │ 32G │ 1.2M │ 32G │ 1% │ /run/wrappers │
# => │ 4 │ /dev/nvme0n1p2 │ 129G │ 101G │ 22G │ 83% │ / │
# => │ 5 │ /dev/nvme0n1p8 │ 48G │ 16G │ 30G │ 35% │ /var │
# => │ 6 │ efivarfs │ 128K │ 24K │ 100K │ 20% │ /sys/firmware/efi/efivars │
# => │ 7 │ tmpfs │ 32G │ 41M │ 32G │ 1% │ /tmp │
# => │ 9 │ /dev/nvme0n1p3 │ 315G │ 230G │ 69G │ 77% │ /home │
# => │ 10 │ /dev/nvme0n1p1 │ 197M │ 120M │ 78M │ 61% │ /boot │
# => │ 11 │ /dev/mapper/vgBigData-lvBigData01 │ 5.5T │ 4.1T │ 1.1T │ 79% │ /bigdata01 │
# => │ 12 │ tmpfs │ 1.0M │ 4.0K │ 1020K │ 1% │ /run/credentials/nix-serve.service │
# => │ 13 │ tmpfs │ 6.3G │ 32M │ 6.3G │ 1% │ /run/user/1000 │
# => ╰────┴───────────────────────────────────┴──────┴──────┴───────┴──────┴────────────────────────────────────╯
```
For an output like from `df` this is probably the most compact way to achieve a nice tabular output.
The `str replace` is needed here because one of the column headers has a space in it.
### Using `from ssv`
Also the builtin `from` data parser for `ssv` (*s*pace *s*eparated *v*alues) can be used:
```nu
df -h | str replace "Mounted on" Mounted_On | from ssv --aligned-columns --minimum-spaces 1
```
The output is identical to the previous example.
`from ssv` supports several modifying flags to tweak its behaviour.
Note we still need to fix the column headers if they contain unexpected spaces.
### Using `parse`
How to parse an arbitrary pattern from a string of text into a multi-column table.
```nu
cargo search shells --limit 10 | lines | parse "{crate_name} = {version} #{description}" | str trim
# => ───┬──────────────┬─────────────────┬────────────────────────────────────────────────────────────────────────────────
# => # │ crate_name │ version │ description
# => ───┼──────────────┼─────────────────┼────────────────────────────────────────────────────────────────────────────────
# => 0 │ shells │ "0.2.0" │ Sugar-coating for invoking shell commands directly from Rust.
# => 1 │ pyc-shell │ "0.3.0" │ Pyc is a simple CLI application, which allows you to perform shell commands in
# => │ │ │ cyrillic and other a…
# => 2 │ ion-shell │ "0.0.0" │ The Ion Shell
# => 3 │ sheldon │ "0.6.6" │ Fast, configurable, shell plugin manager.
# => 4 │ nu │ "0.44.0" │ A new type of shell
# => 5 │ git-gamble │ "2.3.0" │ blend TCR + TDD to make sure to develop the right thing, babystep by babystep
# => 6 │ martin │ "1.0.0-alpha.0" │ Blazing fast and lightweight PostGIS vector tiles server
# => 7 │ fnm │ "1.29.2" │ Fast and simple Node.js version manager
# => 8 │ remote_shell │ "2.0.0" │ remote shell written by rust.
# => 9 │ sauce │ "0.6.6" │ A tool for managing directory-specific state.
# => ───┴──────────────┴─────────────────┴────────────────────────────────────────────────────────────────────────────────
```