awk

Thin wrapper around awk (and gawk-style extensions) that constructs ward.process.cmd(...) invocations.

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 Awk = require("wardlib.app.awk").Awk

Privilege escalation

This module does not implement sudo/doas options. Use wardlib.tools.with middleware when needed.

API

Awk.bin

Executable name or path used for awk.

Awk.cmd(argv)

Low-level escape hatch.

Builds: awk <argv...>

• argv: string[]|nil — raw argv (without the awk binary).

Awk.eval(program, inputs, opts)

Inline program mode.

Builds: awk <opts...> <program> <assigns...> <inputs...>

• program: string — inline awk program.
• inputs: string|string[]|nil — input file(s). When nil, awk reads stdin.
• opts: AwkOpts|nil — modeled options.

Awk.source(programs, inputs, opts)

Multiple inline programs.

Builds: awk <opts...> -e <p1> -e <p2> ... <assigns...> <inputs...>

• programs: string|string[] — one or more programs.

Awk.file(scripts, inputs, opts)

Script file mode.

Builds: awk <opts...> -f <file1> -f <file2> ... <assigns...> <inputs...>

• scripts: string|string[] — one or more .awk script paths.

Options (AwkOpts)

General:

• field_sep: string|nil — -F <sep>.
• vars: table|nil — -v name=value repeated. Accepts:
  • array form: { "k=v", "x=1" }
  • map form: { k = "v", x = 1 } (sorted by key for deterministic argv)
• assigns: table|nil — post-program assignments name=value (array or map; map is sorted by key).
• includes: string[]|nil — gawk: -i <file> repeated.
• extra: string[]|nil — extra args appended before the program/scripts.

Boolean long flags (mostly gawk):

• posix (--posix)
• traditional (--traditional)
• lint (--lint)
• interval (--interval)
• bignum (--bignum)
• sandbox (--sandbox)
• csv (--csv)
• optimize (--optimize)
• ignore_case (--ignore-case)
• characters_as_bytes (--characters-as-bytes)
• use_lc_numeric (--use-lc-numeric)

Optional-value long flags (true => flag only; string => --flag=<value>):

• debug — gawk: --debug[=flags]
• profile — gawk: --profile[=file]
• pretty_print — gawk: --pretty-print[=file]
• dump_variables — gawk: --dump-variables[=file]

Examples

Inline program

local Awk = require("wardlib.app.awk").Awk

-- awk -F: '{print $1}' /etc/passwd
local cmd = Awk.eval("{print $1}", "/etc/passwd", {
  field_sep = ":",
})

With variables (-v) and assignments

local Awk = require("wardlib.app.awk").Awk

-- awk -v a=x -v b=2 '{print a, b, $1}' y=t z=9 /etc/passwd
local cmd = Awk.eval("{print a, b, $1}", "/etc/passwd", {
  vars = { a = "x", b = 2 },
  assigns = { y = "t", z = 9 },
})

Notes:

• vars (-v) are applied before the program.
• assigns (name=value) are appended after the program (and before inputs).

Multiple programs (-e)

local Awk = require("wardlib.app.awk").Awk

-- awk -e 'BEGIN{a=1}' -e '{print a}' input.txt
local cmd = Awk.source({ "BEGIN{a=1}", "{print a}" }, "input.txt")

Script files (-f)

local Awk = require("wardlib.app.awk").Awk

-- awk -f a.awk -f b.awk input.txt
local cmd = Awk.file({ "a.awk", "b.awk" }, "input.txt")

Parse stdout as lines

local Awk = require("wardlib.app.awk").Awk
local out = require("wardlib.tools.out")

local res = Awk.eval("{print $1}", "/etc/passwd"):output()
local lines = out.res(res):ok():lines()