app.lsblk

app.lsblk is a thin command-construction wrapper around the util-linux lsblk binary. It returns ward.process.cmd(...) objects.

lsblk supports JSON output (-J), and this wrapper models that flag.

This module constructs ward.process.cmd(...) invocations; it does not parse output. consumers can use wardlib.tools.out (or their own parsing) on the :output() result.

Import

local Lsblk = require("wardlib.app.lsblk").Lsblk

Privilege escalation

Most lsblk listing operations are unprivileged, but some environments restrict access to block-device metadata. If you need elevation, use wardlib.tools.with.

local with = require("wardlib.tools.with")

local cmd = Lsblk.list(nil, { json = true })
local data = with.with(with.middleware.sudo(), cmd):output()

Options: LsblkOpts

• json: boolean? — -J / --json
• output: string|string[]? — -o <cols> (string or array joined by commas)
• bytes: boolean? — -b
• paths: boolean? — -p
• fs: boolean? — -f
• all: boolean? — -a
• nodeps: boolean? — -d
• list: boolean? — -l
• raw: boolean? — -r
• noheadings: boolean? — -n
• sort: string? — --sort <col>
• tree: boolean? — --tree
• extra: string[]? — appended after modeled options

API

Lsblk.list(devices, opts)

Construct an lsblk command.

Builds: lsblk <opts...> [devices...]

Lsblk.list(devices: string|string[]|nil, opts: LsblkOpts|nil) -> ward.Cmd

Notes:

• If devices is nil, lsblk enumerates all block devices.

Examples

Parse JSON output

local out = require("wardlib.tools.out")

local data = out.cmd(Lsblk.list(nil, { json = true }))
  :label("lsblk -J")
  :json()

-- util-linux typically returns: { blockdevices = [...] }
local devs = data.blockdevices or {}

Select specific columns

-- lsblk -o NAME,SIZE,TYPE,MOUNTPOINT -J
local out = require("wardlib.tools.out")

local data = out.cmd(Lsblk.list(nil, {
  json = true,
  output = { "NAME", "SIZE", "TYPE", "MOUNTPOINT" },
}))
  :label("lsblk -o ... -J")
  :json()

Raw, no headings

-- lsblk -nrp -o NAME,SIZE
Lsblk.list(nil, { noheadings = true, raw = true, paths = true, output = { "NAME", "SIZE" } }):run()