filenames - How to get list of directories in Lua

Question

I need a list of directory in LUA

Suppose I have a directory path as "C:Program Files"

I need a list of all the folders in that particular path and how to search any particular folder in that list.

Example

Need a list of all the folder in path "C:Program Files"

Below are folder name in the above path

1. test123

2. test4567

3. folder 123

4. folder 456

5. folder 456 789

   Need to get the above in a list and then have to search for a particular string like folder 456 in folder 456 789 only.

Have Tried below code. Something I am missing below:-

local function Loc_Lines( str )
--
local ret= {}   -- 0 lines

while str do
    local _,_,line,tail= string.find( str, "(.-)
(.+)" )
    table.insert( ret, line or str )
    str= tail
  Print (str)
end

return ret
end


local function Loc_ShellCommand( cmd )
--
local str= nil

    --
    local f= io.popen( cmd )    -- no command still returns a handle :(
     if f then

        str= f:read'*a'
    Print(str)
        f:close()
    end
    
    if str=="" then   -- take no output as a failure (we can't tell..)
    Print("hi")
        str= nil
    end
 
-- Remove terminating linefeed, if any (eases up one-line analysis)
--
if str then
    if string.sub( str, -1 ) == '
' then
        str= string.sub( str, 1, -2 )
    end
end

return str
 end


 local function Loc_DirCmd( cmd )

 Print(cmd)

  local str= Loc_ShellCommand( cmd )



 return Loc_Lines(str)
 end


local function Loc_DirList( dirname )

 local ret= {}
  
    local lookup= {}

   local tbl= Loc_DirCmd( "dir /AD /B "..dirname )   -- only dirs

    -- Add slash to every dir line
    --
    for i,v in ipairs(tbl) do
        table.insert( ret, v..'\' )
        lookup[v]= true
    end       

    
    -- Return with forward slashes
    --
    if true then
        for i=1,table.getn(ret) do
            ret[i]= string.gsub( ret[i], '\', '/' )
     Print (ret[i])
        end
    end
  

   return ret
 end


 Loc_DirList("C:\Program Files\")

Answer 1

I hate having to install libraries (especially those that want me to use installer packages to install them). If you're looking for a clean solution for a directory listing on an absolute path in Lua, look no further.

Building on the answer that sylvanaar provided, I created a function that returns an array of all the files for a given directory (absolute path required). This is my preferred implementation, as it works on all my machines.

-- Lua implementation of PHP scandir function
function scandir(directory)
    local i, t, popen = 0, {}, io.popen
    local pfile = popen('ls -a "'..directory..'"')
    for filename in pfile:lines() do
        i = i + 1
        t[i] = filename
    end
    pfile:close()
    return t
end

If you are using Windows, you'll need to have a bash client installed so that the 'ls' command will work - alternately, you can use the dir command that sylvanaar provided:

'dir "'..directory..'" /b /ad'