xargs

xargs builds and executes command lines from standard input.

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.

Notes:

• GNU/BSD xargs differ slightly. Use extra to access unmodeled features.
• When using NUL-separated input (-0), ensure the producer uses -print0 / --print0.

Import

local Xargs = require("wardlib.app.xargs").Xargs

API

Xargs.run(cmd, opts)

Builds: xargs <opts...> [-- <cmd...>]

• If cmd is nil, xargs executes its default command (commonly echo, implementation-dependent).
• When cmd is provided, this wrapper emits -- before the command.

Xargs.raw(argv, opts)

Builds: xargs <opts...> <argv...>

Options (XargsOpts)

Common fields:

• Input parsing: null_input (-0) or delimiter (-d <delim>) (mutually exclusive)
• Limits: max_args (-n), max_procs (-P), max_chars (-s)
• Behavior: no_run_if_empty (-r) (GNU)
• Replacement: replace_str (-I <str>)
• Debug: verbose (-t), show_limits (--show-limits) (GNU)
• Escape hatch: extra

Examples

local Xargs = require("wardlib.app.xargs").Xargs

-- xargs -n 10 -t -- echo {}
local cmd1 = Xargs.run({ "echo", "{}" }, { max_args = 10, verbose = true })

-- xargs -0 -P 4 -- rm -f
local cmd2 = Xargs.run({ "rm", "-f" }, { null_input = true, max_procs = 4 })

Pairing with NUL-separated producers

local Find = require("wardlib.app.find").Find
local Xargs = require("wardlib.app.xargs").Xargs

-- find . -type f -name "*.tmp" -print0 | xargs -0 -- rm -f
local find = Find.run(".", { type = "f", name = "*.tmp", print0 = true })
local xargs = Xargs.run({ "rm", "-f" }, { null_input = true })

-- Pipeline wiring depends on your Ward build; the important part is the argv construction.