Command line interface

The command line interface

The command line interface glu makes it possible to create documents without a Go installation. It uses Lua as scripting language, providing a simple yet powerful way to create PDF documents.

Installation

Download the latest binaries at https://github.com/speedata/glu/releases/latest.

If you have a Go installation, you can also build from source:

git clone https://github.com/speedata/glu
cd glu
rake build

Sample document

Create a file hello.lua:

local frontend = require("glu.frontend")

-- Load a font
local doc = frontend.new("hello.pdf")
local ff = doc:new_font_family("text")
local fs = frontend.fontsource({ location = "fonts/CrimsonPro-Regular.ttf" })
ff:add_member(fs, "regular", "normal")

-- Create text content
local txt = frontend.text({
    font_family = ff,
    font_size = "12pt",
    color = "black"
})

local str = [[The quick brown fox jumps over the lazy dog with a very
long line that should be wrapped at some point. This is a test to see
how the text is formatted when it is too long to fit on one line.]]

-- Remove newlines
str = str:gsub("\n", " ")
txt:append(str)

-- Format paragraph and create page
local vlist = doc:format_paragraph(txt, "225pt", { leading = "14pt" })

local page = doc:new_page()
page.width = "210mm"
page.height = "297mm"
page:output_at("1cm", "28cm", vlist)
page:shipout()

doc:finish()
print("Created hello.pdf")

Run with:

glu hello.lua

The documentation is split into parts: general information with code snippets, and the module references.

Dimensions

All dimension parameters accept:

  • Numbers – interpreted as points: 12, 595.28
  • Strings with units – "12pt", "1cm", "10mm", "1in"
  • ScaledPoint – type-safe dimension values (see ScaledPoint)
page.width = "21cm"
page:output_at("2cm", "27cm", vlist)
txt:set("font_size", "14pt")
doc:format_paragraph(txt, 400)  -- 400 points

-- Using ScaledPoint for calculations
local frontend = require("glu.frontend")
local y = frontend.sp_string("28cm")
local h = vlist.height                   -- returns ScaledPoint
page:output_at("2cm", y - h - "1cm", vlist)

Document properties 

local doc = frontend.new("output.pdf")
doc.title = "My Document"
doc.author = "Author Name"
doc.subject = "Document Subject"
doc.creator = "glu"
doc.keywords = "pdf, lua, typesetting"
doc.language = doc:get_language("en")

Attachments 

doc:attach_file({
    filename = "data.xml",
    name = "data.xml",           -- visible name (optional)
    description = "XML data",    -- description (optional)
    mimetype = "text/xml"        -- MIME type (optional)
})

Image inclusion 

-- Load an image file
local imgfile = doc:load_imagefile("image.pdf", 1, "/MediaBox")
-- Arguments: filename, page (optional), box (optional)

-- Create an image node for placement
local imgnode = doc:create_image_node(imgfile, 1, "/MediaBox")
imgnode.width = "5cm"
imgnode.height = "3cm"

-- Pack into vlist and place on page
local node = require("glu.node")
local vl = node.vpack(imgnode)
page:output_at("2cm", "25cm", vl)

Set the PDF format 

doc.format = "PDF/A-3b"  -- or "PDF", "PDF/X-3", "PDF/X-4", "PDF/UA"

For PDF/A-3b with ZUGFeRD support:

doc.format = "PDF/A-3b"
doc.additional_xml_metadata = [[<rdf:Description ...>...</rdf:Description>]]

-- Load ICC color profile
local colorprofile = doc:load_colorprofile("AdobeRGB1998.icc")
colorprofile.identifier = "AdobeRGB1998"
colorprofile.registry = "Adobe"
colorprofile.info = "Adobe RGB (1998)"
colorprofile.condition = "RGB"
colorprofile.colors = 3

Page dimensions 

local page = doc:new_page()
page.width = "210mm"   -- A4 width
page.height = "297mm"  -- A4 height
Architecture overview of “boxes and glue”Using glu