How to read data from a file in Lua

Question

I was wondering if there was a way to read data from a file or maybe just to see if it exists and return a true or false  function fileRead Path LineNumber    --  Code      return Data end

User · Accepted Answer

Try this   -- http   lua-users org wiki FileInputOutput  -- see if the file exists function file exists file    local f   io open file   rb     if f then f close   end   return f    nil end  -- get all lines from a file  returns an empty  -- list table if the file does not exist function lines from file    if not file exists file  then return    end   lines        for line in io lines file  do      lines  lines   1    line   end   return lines end  -- tests the functions above local file    test lua  local lines   lines from file   -- print all line numbers and their contents for k v in pairs lines  do   print  line      k         v  end

User · Answer

You should use the I O Library where you can find all functions at the io table and then use file read to get the file content   local open   io open  local function read file path      local file   open path   rb   -- r read mode and b binary mode     if not file then return nil end     local content   file read   a  --  a or  all reads the whole file     file close       return content end  local fileContent   read file  foo html    print  fileContent

User · Answer

Just a little addition if one wants to parse a space separated text file line by line   read file   function  path  local file   io open path   rb    if not file then return nil end  local lines       for line in io lines path  do     local words          for word in line gmatch   w    do          table insert words  word       end       table insert lines  words  end  file close   return lines  end

User · Answer

There s a I O library available  but if it s available depends on your scripting host  assuming you ve embedded lua somewhere   It s available  if you re using the command line version  The complete I O model is most likely what you re looking for

[lua] How to read data from a file in Lua

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