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-- Text processing functions.
local M = {}
--- Hex encode a string.
---
--- @param str string String to encode
--- @return string : Hex encoded string
function M.hexencode(str)
local bytes = { str:byte(1, #str) }
local enc = {} ---@type string[]
for i = 1, #bytes do
enc[i] = string.format('%02X', bytes[i])
end
return table.concat(enc)
end
--- Hex decode a string.
---
--- @param enc string String to decode
--- @return string? : Decoded string
--- @return string? : Error message, if any
function M.hexdecode(enc)
if #enc % 2 ~= 0 then
return nil, 'string must have an even number of hex characters'
end
local str = {} ---@type string[]
for i = 1, #enc, 2 do
local n = assert(tonumber(enc:sub(i, i + 1), 16))
str[#str + 1] = string.char(n)
end
return table.concat(str), nil
end
return M
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