diff --git a/command.moon b/command.moon
index 3e997f0..2dd064d 100644
--- a/command.moon
+++ b/command.moon
@@ -1,11 +1,42 @@
 -- =========================================================================
 -- capture output of a system command
 -- =========================================================================
-handle = io.popen "ls"
-result = handle\read("*a")
-print result
+-- handle = io.popen "ls"
+-- result = handle\read("*a")
+-- print result
+-- handle\close!
+
+-- os.execute "pandoc"
+
+-- txt = "# hello"
+-- md = "<<EOF\n#{txt}\nEOF"
+-- handle = io.popen "pandoc #{md}", "r"
+-- result = handle\read("*a")
+-- handle\close!
+
+n = os.tmpname!
+handle = io.popen "pandoc > " .. n, "w"
+handle\write "# hello"
 handle\close!
 
+f = io.open n, "r"
+result = f\read("*a")
+f\close!
+-- output = io.input(handle)\read("*a")
+-- handle\write "# hello"
+-- handle\write "EOF"
+
+-- result = handle\read "*a"
+-- handle\close!
+
+
+
+-- handle\flush!
+print result
+-- result\close!
+
+-- require("moon").p handle
+
 -- =========================================================================
 -- how changing the config in the Site class works
 -- =========================================================================
diff --git a/markdown.moon b/markdown.moon
new file mode 100644
index 0000000..975c531
--- /dev/null
+++ b/markdown.moon
@@ -0,0 +1,118 @@
+import Renderer from require "sitegen.renderer"
+
+dollar_temp = "0000sitegen_markdown00dollar0000"
+
+-- a constructor for quote delimited strings
+simple_string = (delim) ->
+  import P from require "lpeg"
+
+  inner = P("\\#{delim}") + "\\\\" + (1 - P delim)
+  inner = inner^0
+  P(delim) * inner * P(delim)
+
+lua_string = ->
+  import P, C, Cmt, Cb, Cg from require "lpeg"
+  check_lua_string = (str, pos, right, left) ->
+    #left == #right
+
+  string_open = P"[" * P"="^0 * "["
+  string_close = P"]" * P"="^0 * "]"
+
+  valid_close = Cmt C(string_close) * Cb"string_open", check_lua_string
+
+  Cg(string_open, "string_open") *
+    (1 - valid_close)^0 * string_close
+
+-- returns a pattern that parses a cosmo template. Can be used to have
+-- pre-processors ignore text that would be handled by cosmo
+parse_cosmo = ->
+  import P, R, Cmt, Cs, V from require "lpeg"
+  curly = P {
+    P"{" * (
+      simple_string("'") +
+      simple_string('"') +
+      lua_string! +
+      V(1) +
+      (P(1) - "}")
+    )^0 * P"}"
+  }
+
+  alphanum = R "az", "AZ", "09", "__"
+  P"$" * alphanum^1 * (curly)^-1
+
+escape_cosmo = (str) ->
+  escapes = {}
+  import P, R, Cmt, Cs, V from require "lpeg"
+
+  counter = 0
+
+  cosmo = parse_cosmo! / (tpl) ->
+    counter += 1
+    key = "#{dollar_temp}.#{counter}"
+    escapes[key] = tpl
+    key
+
+  patt = Cs (cosmo + P(1))^0 * P(-1)
+  str = patt\match(str) or str, escapes
+  str, escapes
+
+unescape_cosmo = (str, escapes) ->
+  import P, R, Cmt, Cs from require "lpeg"
+
+  escape_patt = P(dollar_temp) * P(".") * R("09")^1 / (key) ->
+    escapes[key] or error "bad key for unescape_cosmo"
+
+  patt = Cs (escape_patt + P(1))^0 * P(-1)
+  assert patt\match(str)
+
+-- Converts input from markdown, then passes through cosmo filter from HTML
+-- renderer
+class MarkdownRenderer extends require "sitegen.renderers.html"
+  @escape_cosmo: escape_cosmo
+  @unescape_cosmo: unescape_cosmo
+  @parse_cosmo: parse_cosmo
+
+  source_ext: "md"
+  ext: "html"
+
+  render: (page, md_source) =>
+    discount = require "discount"
+
+    md_source = page\pipe "renderer.markdown.pre_render", md_source
+    md_source, escapes = escape_cosmo md_source
+
+    -- require("moon").p md_source
+    --mathjax --output=../priv/static/posts/#{output_file}.html
+    -- handle = io.popen "pandoc"
+    -- handle\write "# hello"
+    -- handle\flush!
+    -- result = handle\read("*a")
+    -- print result
+    -- handle\close!
+
+    -- require("moon").p result
+
+    -- txt = "# hello"
+    -- md = "<<EOF\n#{md_source}\nEOF"
+    -- require("moon").p md
+    -- n = os.tmpname!
+    -- handle = io.popen "pandoc > " .. n, "w"
+    -- handle\write "# hello"
+    -- result = handle\read("*a")
+    -- handle\close!
+
+    n = os.tmpname!
+    handle = io.popen "pandoc > " .. n, "w"
+    handle\write md_source
+    handle\close!
+
+    f = io.open n, "r"
+    result = f\read("*a")
+    f\close!
+
+    html_source = assert result
+    -- html_source = assert discount md_source
+    html_source = unescape_cosmo html_source, escapes
+
+    super page, html_source
+
diff --git a/site.moon b/site.moon
index 787c1ff..91b9e49 100644
--- a/site.moon
+++ b/site.moon
@@ -119,12 +119,21 @@ sitegen.create =>
 
   -- @what!
 
-  add "index.html", o: one
+  add "index.html"
   add path, target: out, template: "blog", is_a: "post", post: {
     publish_date: publish_date(path)
   }, id: extract_id(path) for path, out in pairs posts "docs"
 
-  add "test.html", id: "test"
+  -- add "docs/2023-11-15-test-mix-task-file-modify.md",
+  --   target: "posts/2023-11-15-test-mix-task-file-modify.html"
+  --   template: "blog"
+  --   is_a: "post"
+  --   post: {
+  --     publish_date: publish_date "docs/2023-11-15-test-mix-task-file-modify.md"
+  --   }
+  --   id: extract_id "docs/2023-11-15-test-mix-task-file-modify.md"
+
+  -- add "test.md"
   -- feed "posts.moon", "feed.xml"
 
   -- require("moon").p site