Lua Requires Chilkat v11.7.0+

Extract Text from a PDF that Forbids Copying

See more PDF Text Extraction Examples

Demonstrates a PDF that opens without a password but whose permissions do not allow copying text. The "text", "markdown", "search" and "tables" operations fail with that reason; "assess" always works. Loading the PDF with the OwnerPassword property set grants owner rights, and extraction works. Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

-- The PDF used in this example (owner password: owner-secret; copying not permitted) is available at no_copy_permission.pdf

local pdf = chilkat.Pdf.new()
local json = chilkat.JsonObject.new()
local jsonOut = chilkat.JsonObject.new()

-- The PDF opens without a password.
local success = pdf:load_file("qa_data/pdf/no_copy_permission.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

-- Extracting text is refused, because the PDF's permissions do not allow copying.
success = pdf:extract_text("text", json, jsonOut)
if not success then
    print("Extraction refused: " .. pdf.last_error_text)
end

-- "assess" reports only counts and ratings, never text, so it is always allowed.
success = pdf:extract_text("assess", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("rating: " .. jsonOut:string_of("quality.rating"))

-- Load with the owner password to get owner rights, which include copying.
pdf.owner_password = "owner-secret"
success = pdf:load_file("qa_data/pdf/no_copy_permission.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

success = pdf:extract_text("text", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print(jsonOut:string_of("text"))

-- Sample output:

-- Extraction refused: ChilkatLog:
--   ExtractText:
--     ...
--       The PDF's permissions do not allow copying or extracting text (load it with the owner password to extract).
--     ...
-- rating: good
-- Visitor Leaflet
--
-- Welcome to the harbor lighthouse. The tower is open on weekends from July to September.
--
-- Please keep to the marked paths and do not climb on the breakwater.
--
-- The lantern room is closed in high winds.