main
 |-- hello  (you are here)
 `-- world  (given "world", you need to cd here)

import os
os.system('cd ../'+input())

import os
os.chdir("../"+input())

import os
os.chdir(os.path.join("..",input()))

cat $1 | tr "()" "<>" > $1.tmp
scheme-thingy $1.tmp

  /\
 /+ \
/x y \
------

   ^
  /+\
 ^---^
/3\ /4\
--- ---

#!/usr/bin/env python3
import os, sys
os.system("/opt/racket/bin/racket "+sys.argv[1])

#!/usr/bin/env python3
import os, sys, string
code=sys.argv[1].translate(string.maketrans("<>", "()"))
os.system("/opt/racket/bin/racket "+code)

#!/usr/bin/env python3
import os, sys, string
code=sys.argv[1].translate(string.maketrans("<>", "()"))
os.system("/opt/racket/bin/racket "+code+" < "+sys.stdin.read())

#!/usr/bin/env python3
import os, sys, string
code=sys.argv[1].translate(string.maketrans("<>", "()"))
with open("code.as", 'w') as f:
    f.write(code)
os.system("/opt/racket/bin/racket code.as < "+sys.stdin.read())

#!/usr/bin/env python3
import os, sys, string
code=sys.argv[1].translate(string.maketrans("<>", "()"))
with open("code.as", 'w') as f:
    f.write(code)
os.system("/opt/racket/bin/racket code.as <<< \""+sys.stdin.read().replace("\"","\\\"")+"\"")

#!/usr/bin/env python3
import os, sys, string
code=sys.argv[1].translate(string.maketrans("<>", "()"))
with open("code.as", 'w') as f:
    f.write(code)
os.system("/opt/racket/bin/racket code.as <<< \""+sys.stdin.read().replace("\"","\\\"").replace("\\","\\\\")+"\"")