CODEWITHSUNDEEP
lua
Pop 111
Pop 111

Reputation: 1

Is it possible to perform a hexdump in Lua code

I'm used to using C but I'm new to Lua. Is there a way to create a Lua program that can read example.exe and give me the program's code in hexadecimal?

Upvotes: 0

Views: 1086

Answers (2)

tonypdmtr
tonypdmtr

Reputation: 3225

Another possibility:

local filename = arg[1]

if filename == nil then
  print [=[
Usage: dump <filename> [bytes_per_line(16)]]=]
  return
end

local f = assert(io.open(filename, 'rb'))
local block = tonumber(arg[2]) or 16

while true do
  local bytes = f:read(block)
  if not bytes then return end
  for b in bytes:gmatch('.') do
    io.write(('%02X '):format(b:byte()))
  end
  io.write(('   '):rep(block - bytes:len() + 1))
  io.write(bytes:gsub('%c', '.'), '\n')
end

Upvotes: 2

lhf
lhf

Reputation: 72352

Until Lua 5.1, this sample program xd.lua was included in the distribution:

-- hex dump
-- usage: lua xd.lua < file

local offset=0
while true do
 local s=io.read(16)
 if s==nil then return end
 io.write(string.format("%08X  ",offset))
 string.gsub(s,"(.)",
    function (c) io.write(string.format("%02X ",string.byte(c))) end)
 io.write(string.rep(" ",3*(16-string.len(s))))
 io.write(" ",string.gsub(s,"%c","."),"\n") 
 offset=offset+16
end

Upvotes: 4

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