Greatly simplified the LuaRocks fs abstractions system

git-svn-id: http://luarocks.org/svn/luarocks/trunk@8 9ca3f7c1-7366-0410-b1a3-b5c78f85698c

7 files changed, 98 insertions, 757 deletions

diff --git a/src/luarocks/cfg.lua b/src/luarocks/cfg.lua
index 71efea47..b667f8e7 100644
--- a/src/luarocks/cfg.lua
+++ b/src/luarocks/cfg.lua
@@ -1,6 +1,6 @@
 
-local rawset, next, table, pairs, print, require, io, os, setmetatable =
-      rawset, next, table, pairs, print, require, io, os, setmetatable
+local rawset, next, table, pairs, print, require, io, os, setmetatable, program_version =
+      rawset, next, table, pairs, print, require, io, os, setmetatable, program_version
 
 --- Configuration for LuaRocks.
 -- Tries to load the user's configuration file and
diff --git a/src/luarocks/fs.lua b/src/luarocks/fs.lua
index a905755d..d2cb3ddb 100644
--- a/src/luarocks/fs.lua
+++ b/src/luarocks/fs.lua
@@ -1,5 +1,5 @@
 
-local rawset = rawset
+local pairs = pairs
 
 --- Proxy module for filesystem and platform abstractions.
 -- All code using "fs" code should require "luarocks.fs",
@@ -10,33 +10,30 @@ module("luarocks.fs", package.seeall)
 
 local cfg = require("luarocks.cfg")
 
-local fs_impl = nil
-for _, platform in ipairs(cfg.platforms) do
-   local ok, result = pcall(require, "luarocks.fs."..platform)
-   if ok then
-      fs_impl = result
-      if fs_impl then
-         break
+local function load_fns(fs_table)
+   for name, fn in pairs(fs_table) do
+      if not _M[name] then
+         _M[name] = fn
       end
    end
 end
 
-local fs_lua = require("luarocks.fs.lua")
-local fs_unix = require("luarocks.fs.unix")
-
-local fs_mt = {
-   __index = function(t, k)
-      local impl = fs_lua[k] or fs_impl[k] or fs_unix[k]
-      rawset(t, k, impl)
-      return impl
+-- Load platform-specific functions
+local loaded_platform = nil
+for _, platform in ipairs(cfg.platforms) do
+   local ok, fs_plat = pcall(require, "luarocks.fs."..platform)
+   if ok and fs_plat then
+      loaded_platform = platform
+      load_fns(fs_plat)
+      break
    end
-}
+end
 
-setmetatable(luarocks.fs, fs_mt)
+-- Load platform-independent pure-Lua functionality
+local fs_lua = require("luarocks.fs.lua")
+load_fns(fs_lua)
 
-fs_lua.init_fs_functions(luarocks.fs)
-fs_unix.init_fs_functions(luarocks.fs)
-if fs_impl then
-   fs_impl.init_fs_functions(luarocks.fs)
-end
+-- Load platform-specific fallbacks for missing Lua modules
+local ok, fs_plat_tools = pcall(require, "luarocks.fs."..loaded_platform..".tools")
+if ok and fs_plat_tools then load_fns(fs_plat_tools) end
 
diff --git a/src/luarocks/fs/lua.lua b/src/luarocks/fs/lua.lua
index 7d411e49..9f9a4b63 100644
--- a/src/luarocks/fs/lua.lua
+++ b/src/luarocks/fs/lua.lua
@@ -6,6 +6,8 @@ local assert, type, table, io, package, math, os, ipairs =
 -- using LuaFileSystem, LZLib, MD5 and LuaCurl.
 module("luarocks.fs.lua", package.seeall)
 
+local fs = require("luarocks.fs")
+
 local cfg = require("luarocks.cfg")
 local dir = require("luarocks.dir")
 
@@ -23,36 +25,6 @@ math.randomseed(os.time())
 
 dir_separator = "/"
 
-local fs_absolute_name,
-      fs_copy,
-      fs_current_dir,
-      fs_dir_stack,
-      fs_execute,
-      fs_execute_string,
-      fs_exists,
-      fs_find,
-      fs_is_dir,
-      fs_is_file,
-      fs_make_dir,
-      fs_set_time,
-      fs_Q
-
-function init_fs_functions(impl)
-   fs_absolute_name = impl.absolute_name
-   fs_copy = impl.copy
-   fs_current_dir = impl.current_dir
-   fs_dir_stack = impl.dir_stack
-   fs_execute = impl.execute
-   fs_execute_string = impl.execute_string
-   fs_exists = impl.exists
-   fs_find = impl.find
-   fs_is_dir = impl.is_dir
-   fs_is_file = impl.is_file
-   fs_make_dir = impl.make_dir
-   fs_set_time = impl.set_time
-   fs_Q = impl.Q
-end
-
 --- Quote argument for shell processing.
 -- Adds single quotes and escapes.
 -- @param arg string: Unquoted argument.
@@ -73,7 +45,7 @@ end
 function is_writable(file)
    assert(file)
    local result
-   if fs_is_dir(file) then
+   if fs.is_dir(file) then
       local file2 = file .. '/.tmpluarockstestwritable'
       local fh = io.open(file2, 'w')
       result = fh ~= nil
@@ -95,31 +67,13 @@ function make_temp_dir(name)
    assert(type(name) == "string")
 
    local temp_dir = (os.getenv("TMP") or "/tmp") .. "/luarocks_" .. name:gsub(dir.separator, "_") .. "-" .. tostring(math.floor(math.random() * 10000))
-   if fs_make_dir(temp_dir) then
+   if fs.make_dir(temp_dir) then
       return temp_dir
    else
       return nil
    end
 end
 
---- Return an absolute pathname from a potentially relative one.
--- @param pathname string: pathname to convert.
--- @param relative_to string or nil: path to prepend when making
--- pathname absolute, or the current dir in the dir stack if
--- not given.
--- @return string: The pathname converted to absolute.
-function absolute_name(pathname, relative_to)
-   assert(type(pathname) == "string")
-   assert(type(relative_to) == "string" or not relative_to)
-
-   relative_to = relative_to or fs_current_dir()
-   if pathname:sub(1,1) == "/" then
-      return pathname
-   else
-      return relative_to .. "/" .. pathname
-   end
-end
-
 --- Split protocol and path from an URL or local pathname.
 -- URLs should be in the "protocol://path" format.
 -- For local pathnames, "file" is returned as the protocol.
@@ -134,11 +88,28 @@ function split_url(url)
       pathname = url
    end
    if protocol == "file" then
-      pathname = fs_absolute_name(pathname)
+      pathname = fs.absolute_name(pathname)
    end
    return protocol, pathname
 end
 
+--- Run the given command, quoting its arguments.
+-- The command is executed in the current directory in the dir stack.
+-- @param command string: The command to be executed. No quoting/escaping
+-- is applied.
+-- @param ... Strings containing additional arguments, which are quoted.
+-- @return boolean: true if command succeeds (status code 0), false
+-- otherwise.
+function execute(command, ...)
+   assert(type(command) == "string")
+   
+   for _, arg in ipairs({...}) do
+      assert(type(arg) == "string")
+      command = command .. " " .. fs.Q(arg)
+   end
+   return fs.execute_string(command)
+end
+
 ---------------------------------------------------------------------
 -- LuaFileSystem functions
 ---------------------------------------------------------------------
@@ -158,23 +129,6 @@ function execute_string(cmd)
    end
 end
 
---- Run the given command, quoting its arguments.
--- The command is executed in the current directory in the dir stack.
--- @param command string: The command to be executed. No quoting/escaping
--- is applied.
--- @param ... Strings containing additional arguments, which are quoted.
--- @return boolean: true if command succeeds (status code 0), false
--- otherwise.
-function execute(command, ...)
-   assert(type(command) == "string")
-   
-   for _, arg in ipairs({...}) do
-      assert(type(arg) == "string")
-      command = command .. " " .. fs_Q(arg)
-   end
-   return fs_execute_string(command)
-end
-
 --- Obtain current directory.
 -- Uses the module's internal dir stack.
 -- @return string: the absolute pathname of the current directory.
@@ -190,7 +144,6 @@ end
 function change_dir(d)
    table.insert(dir_stack, lfs.currentdir())
    lfs.chdir(d)
---local x="CHDIR: " for _,d in ipairs(dir_stack) do x=x.." "..d end print(x)
 end
 
 --- Change directory to root.
@@ -200,14 +153,12 @@ function change_dir_to_root()
    table.insert(dir_stack, lfs.currentdir())
    -- TODO Does this work on Windows?
    lfs.chdir("/")
---local x="CHDIR ROOT: " for _,d in ipairs(dir_stack) do x=x.." "..d end print(x)
 end
 
 --- Change working directory to the previous in the dir stack.
 -- @return true if a pop ocurred, false if the stack was empty.
 function pop_dir()
    local d = table.remove(dir_stack)
---local x="POP DIR: " for _,d in ipairs(dir_stack) do x=x.." "..d end print(x)
    if d then
       lfs.chdir(d)
       return true
@@ -280,11 +231,11 @@ local function recursive_copy(src, dest)
    local srcmode = lfs.attributes(src, "mode")
       
    if srcmode == "file" then
-      local ok = fs_copy(src, dest)
+      local ok = fs.copy(src, dest)
       if not ok then return false end
    elseif srcmode == "directory" then
       local subdir = dir.path(dest, dir.base_name(src))
-      fs_make_dir(subdir)
+      fs.make_dir(subdir)
       for file in lfs.dir(src) do
          if file ~= "." and file ~= ".." then
             local ok = recursive_copy(dir.path(src, file), subdir)
@@ -354,9 +305,9 @@ end
 function list_dir(at)
    assert(type(at) == "string" or not at)
    if not at then
-      at = fs_current_dir()
+      at = fs.current_dir()
    end
-   if not fs_is_dir(at) then
+   if not fs.is_dir(at) then
       return {}
    end
    local result = {}
@@ -392,9 +343,9 @@ end
 function find(at)
    assert(type(at) == "string" or not at)
    if not at then
-      at = fs_current_dir()
+      at = fs.current_dir()
    end
-   if not fs_is_dir(at) then
+   if not fs.is_dir(at) then
       return {}
    end
    local result = {}
@@ -448,7 +399,7 @@ end
 function unzip(zipfile)
    assert(zipfile)
    -- FIXME!!!!
-   return fs_execute("unzip", zipfile)
+   return fs.execute("unzip", zipfile)
 end
 
 end
@@ -506,7 +457,7 @@ if md5_ok then
 -- @return boolean: true if the MD5 checksum for 'file' equals 'md5sum', false if not
 -- or if it could not perform the check for any reason.
 function check_md5(file, md5sum)
-   file = fs_absolute_name(file)
+   file = fs.absolute_name(file)
    local file = io.open(file, "r")
    if not file then return false end
    local computed = md5.sumhexa(file:read("*a"))
@@ -545,13 +496,13 @@ function unpack_archive(archive)
 
    local ok
    if archive:match("%.tar%.gz$") or archive:match("%.tgz$") then
-      -- ok = fs_execute("tar zxvpf ", archive)
-      ok = fs_execute_string("gunzip -c "..archive.."|tar -xf -")
+      -- ok = fs.execute("tar zxvpf ", archive)
+      ok = fs.execute_string("gunzip -c "..archive.."|tar -xf -")
    elseif archive:match("%.tar%.bz2$") then
-      -- ok = fs_execute("tar jxvpf ", archive)
-      ok = fs_execute_string("bunzip2 -c "..archive.."|tar -xf -")
+      -- ok = fs.execute("tar jxvpf ", archive)
+      ok = fs.execute_string("bunzip2 -c "..archive.."|tar -xf -")
    elseif archive:match("%.zip$") then
-      ok = fs_execute("unzip ", archive)
+      ok = fs.execute("unzip ", archive)
    elseif archive:match("%.lua$") or archive:match("%.c$") then
       -- Ignore .lua and .c files; they don't need to be extracted.
       return true
diff --git a/src/luarocks/fs/unix.lua b/src/luarocks/fs/unix.lua
index 1f8411c9..dba152ef 100644
--- a/src/luarocks/fs/unix.lua
+++ b/src/luarocks/fs/unix.lua
@@ -5,389 +5,14 @@ local assert, type, table, io, package, math, os, ipairs =
 --- Unix implementation of filesystem and platform abstractions.
 module("luarocks.fs.unix", package.seeall)
 
+local fs = require("luarocks.fs")
+
 local cfg = require("luarocks.cfg")
 local dir = require("luarocks.dir")
+local fs = require("luarocks.fs")
 
 math.randomseed(os.time())
 
-dir_stack = {}
-
-local fs_absolute_name,
-      fs_copy,
-      fs_current_dir,
-      fs_dir_stack,
-      fs_execute,
-      fs_execute_string,
-      fs_is_dir,
-      fs_is_file,
-      fs_make_dir,
-      fs_exists,
-      fs_find,
-      fs_Q
-
-function init_fs_functions(impl)
-   fs_absolute_name = impl.absolute_name
-   fs_copy = impl.copy
-   fs_current_dir = impl.current_dir
-   fs_dir_stack = impl.dir_stack
-   fs_execute = impl.execute
-   fs_execute_string = impl.execute_string
-   fs_is_dir = impl.is_dir
-   fs_is_file = impl.is_file
-   fs_make_dir = impl.make_dir
-   fs_exists = impl.exists
-   fs_find = impl.find
-   fs_Q = impl.Q
-end
-
---- Quote argument for shell processing.
--- Adds single quotes and escapes.
--- @param arg string: Unquoted argument.
--- @return string: Quoted argument.
-function Q(arg)
-   assert(type(arg) == "string")
-
-   return "'" .. arg:gsub("\\", "\\\\"):gsub("'", "'\\''") .. "'"
-end
-
---- Obtain current directory.
--- Uses the module's internal dir stack.
--- @return string: the absolute pathname of the current directory.
-function current_dir()
-   local current = os.getenv("PWD")
-   if not current then
-      local pipe = io.popen("pwd")
-      current = pipe:read("*l")
-      pipe:close()
-   end
-   for _, d in ipairs(fs_dir_stack) do
-      current = fs_absolute_name(d, current)
-   end
-   return current
-end
-
---- Run the given command.
--- The command is executed in the current directory in the dir stack.
--- @param cmd string: No quoting/escaping is applied to the command.
--- @return boolean: true if command succeeds (status code 0), false
--- otherwise.
-function execute_string(cmd)
-   if os.execute("cd " .. fs_Q(fs_current_dir()) .. " && " .. cmd) == 0 then
-      return true
-   else
-      return false
-   end
-end
-
---- Run the given command, quoting its arguments.
--- The command is executed in the current directory in the dir stack.
--- @param command string: The command to be executed. No quoting/escaping
--- is applied.
--- @param ... Strings containing additional arguments, which are quoted.
--- @return boolean: true if command succeeds (status code 0), false
--- otherwise.
-function execute(command, ...)
-   assert(type(command) == "string")
-   
-   for _, arg in ipairs({...}) do
-      assert(type(arg) == "string")
-      command = command .. " " .. fs_Q(arg)
-   end
-   return fs_execute_string(command)
-end
-
---- Change the current directory.
--- Uses the module's internal dir stack. This does not have exact
--- semantics of chdir, as it does not handle errors the same way,
--- but works well for our purposes for now.
--- @param d string: The directory to switch to.
-function change_dir(d)
-   assert(type(d) == "string")
-   table.insert(fs_dir_stack, d)
-end
-
---- Change directory to root.
--- Allows leaving a directory (e.g. for deleting it) in
--- a crossplatform way.
-function change_dir_to_root()
-   table.insert(fs_dir_stack, "/")
-end
-
---- Change working directory to the previous in the dir stack.
-function pop_dir()
-   local d = table.remove(fs_dir_stack)
-   return d ~= nil
-end
-
---- Create a directory if it does not already exist.
--- If any of the higher levels in the path name does not exist
--- too, they are created as well.
--- @param d string: pathname of directory to create.
--- @return boolean: true on success, false on failure.
-function make_dir(d)
-   assert(d)
-   return fs_execute("mkdir -p", d)
-end
-
---- Remove a directory if it is empty.
--- Does not return errors (for example, if directory is not empty or
--- if already does not exist)
--- @param dir string: pathname of directory to remove.
-function remove_dir_if_empty(d)
-   assert(d)
-   fs_execute_string("rmdir "..fs_Q(d).." 1> /dev/null 2> /dev/null")
-end
-
---- Copy a file.
--- @param src string: Pathname of source
--- @param dest string: Pathname of destination
--- @return boolean or (boolean, string): true on success, false on failure,
--- plus an error message.
-function copy(src, dest)
-   assert(src and dest)
-   if fs_execute("cp", src, dest) then
-      return true
-   else
-      return false, "Failed copying "..src.." to "..dest
-   end
-end
-
---- Recursively copy the contents of a directory.
--- @param src string: Pathname of source
--- @param dest string: Pathname of destination
--- @return boolean or (boolean, string): true on success, false on failure,
--- plus an error message.
-function copy_contents(src, dest)
-   assert(src and dest)
-   if fs_execute_string("cp -pPR "..fs_Q(src).."/* "..fs_Q(dest).." 1> /dev/null 2>/dev/null") then
-      return true
-   else
-      return false, "Failed copying "..src.." to "..dest
-   end
-end
-
---- Delete a file or a directory and all its contents.
--- For safety, this only accepts absolute paths.
--- @param arg string: Pathname of source
--- @return boolean: true on success, false on failure.
-function delete(arg)
-   assert(arg)
-   assert(arg:sub(1,1) == "/")
-   return fs_execute_string("rm -rf " .. fs_Q(arg) .. " 1> /dev/null 2>/dev/null")
-end
-
---- List the contents of a directory. 
--- @param at string or nil: directory to list (will be the current
--- directory if none is given).
--- @return table: an array of strings with the filenames representing
--- the contents of a directory.
-function list_dir(at)
-   assert(type(at) == "string" or not at)
-   if not at then
-      at = fs_current_dir()
-   end
-   if not fs_is_dir(at) then
-      return {}
-   end
-   local result = {}
-   local pipe = io.popen("cd "..fs_Q(at).." && ls")
-   for file in pipe:lines() do
-      table.insert(result, file)
-   end
-   pipe:close()
-   return result
-end
-
---- Recursively scan the contents of a directory. 
--- @param at string or nil: directory to scan (will be the current
--- directory if none is given).
--- @return table: an array of strings with the filenames representing
--- the contents of a directory.
-function find(at)
-   assert(type(at) == "string" or not at)
-   if not at then
-      at = fs_current_dir()
-   end
-   if not fs_is_dir(at) then
-      return {}
-   end
-   local result = {}
-   local pipe = io.popen("cd "..fs_Q(at).." && find * 2>/dev/null") 
-   for file in pipe:lines() do
-      table.insert(result, file)
-   end
-   pipe:close()
-   return result
-end
-
---- Compress files in a .zip archive.
--- @param zipfile string: pathname of .zip archive to be created.
--- @param ... Filenames to be stored in the archive are given as
--- additional arguments.
--- @return boolean: true on success, false on failure.
-function zip(zipfile, ...)
-   return fs_execute("zip -r", zipfile, ...)
-end
-
---- Uncompress files from a .zip archive.
--- @param zipfile string: pathname of .zip archive to be extracted.
--- @return boolean: true on success, false on failure.
-function unzip(zipfile)
-   assert(zipfile)
-   return fs_execute("unzip", zipfile)
-end
-
---- Test for existance of a file.
--- @param file string: filename to test
--- @return boolean: true if file exists, false otherwise.
-function exists(file)
-   assert(file)
-   return fs_execute("test -r", file)
-end
-
---- Test is file/dir is writable.
--- @param file string: filename to test
--- @return boolean: true if file exists, false otherwise.
-function is_writable(file)
-   assert(file)
-   return fs_execute("test -w", file)
-end
-
---- Test is pathname is a directory.
--- @param file string: pathname to test
--- @return boolean: true if it is a directory, false otherwise.
-function is_dir(file)
-   assert(file)
-   return fs_execute("test -d", file)
-end
-
---- Test is pathname is a regular file.
--- @param file string: pathname to test
--- @return boolean: true if it is a regular file, false otherwise.
-function is_file(file)
-   assert(file)
-   return fs_execute("test -f", file)
-end
-
---- Download a remote file.
--- @param url string: URL to be fetched.
--- @param filename string or nil: this function attempts to detect the
--- resulting local filename of the remote file as the basename of the URL;
--- if that is not correct (due to a redirection, for example), the local
--- filename can be given explicitly as this second argument.
--- @return boolean: true on success, false on failure.
-function download(url, filename)
-   assert(type(url) == "string")
-   assert(type(filename) == "string" or not filename)
-
-   if cfg.downloader == "wget" then
-      local wget_cmd = "wget --user-agent="..cfg.user_agent.." --quiet --continue "
-      if filename then
-         return fs_execute(wget_cmd.." --output-document ", filename, url)
-      else
-         return fs_execute(wget_cmd, url)
-      end
-   elseif cfg.downloader == "curl" then
-      filename = filename or dir.base_name(url)
-      return fs_execute_string("curl --user-agent "..cfg.user_agent.." "..fs_Q(url).." 2> /dev/null 1> "..fs_Q(filename))
-   end
-end
-
---- Create a temporary directory.
--- @param name string: name pattern to use for avoiding conflicts
--- when creating temporary directory.
--- @return string or nil: name of temporary directory or nil on failure.
-function make_temp_dir(name)
-   assert(type(name) == "string")
-
-   local temp_dir = (os.getenv("TMP") or "/tmp") .. "/luarocks_" .. name:gsub(dir.separator, "_") .. "-" .. tostring(math.floor(math.random() * 10000))
-   if fs_make_dir(temp_dir) then
-      return temp_dir
-   else
-      return nil
-   end
-end
-
-function chmod(pathname, mode)
-  return fs_execute("chmod "..mode, pathname)
-end
-
---- Apply a patch.
--- @param patchname string: The filename of the patch.
-function apply_patch(patchname)
-   return fs_execute("patch -p1 -f -i ", patchname)
-end
-
---- Unpack an archive.
--- Extract the contents of an archive, detecting its format by
--- filename extension.
--- @param archive string: Filename of archive.
--- @return boolean or (boolean, string): true on success, false and an error message on failure.
-function unpack_archive(archive)
-   assert(type(archive) == "string")
-
-   local ok
-   if archive:match("%.tar%.gz$") or archive:match("%.tgz$") then
-      -- ok = fs_execute("tar zxvpf ", archive)
-         ok = fs_execute_string("gunzip -c "..archive.."|tar -xf -")
-   elseif archive:match("%.tar%.bz2$") then
-      -- ok = fs_execute("tar jxvpf ", archive)
-         ok = fs_execute_string("bunzip2 -c "..archive.."|tar -xf -")
-   elseif archive:match("%.zip$") then
-      ok = fs_execute("unzip ", archive)
-   elseif archive:match("%.lua$") or archive:match("%.c$") then
-      -- Ignore .lua and .c files; they don't need to be extracted.
-      return true
-   else
-      local ext = archive:match(".*(%..*)")
-      return false, "Unrecognized filename extension "..(ext or "")
-   end
-   if not ok then
-      return false, "Failed extracting "..archive
-   end
-   return true
-end
-
---- Check the MD5 checksum for a file.
--- @param file string: The file to be checked.
--- @param md5sum string: The string with the expected MD5 checksum.
--- @return boolean: true if the MD5 checksum for 'file' equals 'md5sum', false if not
--- or if it could not perform the check for any reason.
-function check_md5(file, md5sum)
-   file = fs_absolute_name(file)
-   local computed
-   if cfg.md5checker == "md5sum" then
-      local pipe = io.popen("md5sum "..file)
-      computed = pipe:read("*l"):gsub("[^%x]+", "")
-      pipe:close()
-      if computed then
-         computed = computed:sub(1,32)
-      end
-   elseif cfg.md5checker == "openssl" then
-      local pipe = io.popen("openssl md5 "..file)
-      computed = pipe:read("*l")
-      pipe:close()
-      if computed then
-         computed = computed:sub(-32)
-      end
-   elseif cfg.md5checker == "md5" then
-      local pipe = io.popen("md5 "..file)
-      computed = pipe:read("*l")
-      pipe:close()
-      if computed then
-         computed = computed:sub(-32)
-      end
-   end
-   if not computed then
-      return false
-   end
-   if computed:match("^"..md5sum) then
-      return true
-   else
-      return false
-   end
-end
-
 --- Return an absolute pathname from a potentially relative one.
 -- @param pathname string: pathname to convert.
 -- @param relative_to string or nil: path to prepend when making
@@ -398,7 +23,7 @@ function absolute_name(pathname, relative_to)
    assert(type(pathname) == "string")
    assert(type(relative_to) == "string" or not relative_to)
 
-   relative_to = relative_to or fs_current_dir()
+   relative_to = relative_to or fs.current_dir()
    if pathname:sub(1,1) == "/" then
       return pathname
    else
@@ -420,7 +45,7 @@ function split_url(url)
       pathname = url
    end
    if protocol == "file" then
-      pathname = fs_absolute_name(pathname)
+      pathname = fs.absolute_name(pathname)
    end
    return protocol, pathname
 end
@@ -446,7 +71,7 @@ function wrap_script(file, dest)
    wrapper:write('export LUA_PATH LUA_CPATH\n')
    wrapper:write('exec "'..dir.path(cfg.variables["LUA_BINDIR"], cfg.lua_interpreter)..'" -lluarocks.require "'..file..'" "$@"\n')
    wrapper:close()
-   if fs_execute("chmod +x",wrapname) then
+   if fs.execute("chmod +x",wrapname) then
       return true
    else
       return nil, "Could not make "..wrapname.." executable."
@@ -487,7 +112,33 @@ function is_actual_binary(filename)
    return false
 end
 
+function is_actual_binary(filename)
+   if filename:match("%.lua$") then
+      return false
+   end
+   local file = io.open(filename)
+   if file then
+      local found = false
+      local first = file:read()
+      if first:match("#!.*lua") then
+         file:close()
+         return true
+      elseif first:match("#!/bin/sh") then
+         local line = file:read()
+         line = file:read()
+         if not(line and line:match("LUA_PATH")) then
+            file:close()
+            return true
+         end
+      end
+      file:close()
+   else
+      return true
+   end
+   return false
+end
+
 function copy_binary(filename, dest) 
-   return fs_copy(filename, dest)
+   return fs.copy(filename, dest)
 end
 
diff --git a/src/luarocks/fs/win32.lua b/src/luarocks/fs/win32.lua
index da9b7d60..d005781e 100644
--- a/src/luarocks/fs/win32.lua
+++ b/src/luarocks/fs/win32.lua
@@ -3,25 +3,11 @@
 -- used by this module.
 module("luarocks.fs.win32", package.seeall)
 
+local fs = require("luarocks.fs")
+
 local cfg = require("luarocks.cfg")
 local dir = require("luarocks.dir")
 
-local fs_copy,
-      fs_current_dir,
-      fs_execute,
-      fs_execute_string,
-      fs_is_dir,
-      fs_Q
-
-function init_fs_functions(impl)
-   fs_copy = impl.copy
-   fs_current_dir = impl.current_dir
-   fs_execute = impl.execute
-   fs_execute_string = impl.execute_string
-   fs_is_dir = impl.is_dir
-   fs_Q = impl.Q
-end
-
 --- Quote argument for shell processing. Fixes paths on Windows.
 -- Adds single quotes and escapes.
 -- @param arg string: Unquoted argument.
@@ -36,202 +22,6 @@ function Q(arg)
    return '"' .. arg:gsub('"', '\\"') .. '"'
 end
 
-local function command_at(directory, cmd)
-   local drive = directory:match("^([A-Za-z]:)")
-   cmd = "cd " .. fs_Q(directory) .. " & " .. cmd
-   if drive then
-      cmd = drive .. " & " .. cmd
-   end
-   return cmd
-end
-
---- Run the given command.
--- The command is executed in the current directory in the dir stack.
--- @param cmd string: No quoting/escaping is applied to the command.
--- @return boolean: true if command succeeds (status code 0), false
--- otherwise.
-function execute_string(cmd)
-   if os.execute(command_at(fs_current_dir(), cmd)) == 0 then
-      return true
-   else
-      return false
-   end
-end
-
---- Test for existance of a file.
--- @param file string: filename to test
--- @return boolean: true if file exists, false otherwise.
-function exists(file)
-   assert(file)
-   return fs_execute("if not exist " .. fs_Q(file) ..
-                     " invalidcommandname 2>NUL 1>NUL")
-end
-
---- Test is pathname is a directory.
--- @param file string: pathname to test
--- @return boolean: true if it is a directory, false otherwise.
-function is_dir(file)
-   assert(file)
-   return fs_execute("chdir /D " .. fs_Q(file) .. " 2>NUL 1>NUL")
-end
-
---- Test is pathname is a regular file.
--- @param file string: pathname to test
--- @return boolean: true if it is a regular file, false otherwise.
-function is_dir(file)
-   assert(file)
-   return fs_execute("test -d" .. fs_Q(file) .. " 2>NUL 1>NUL")
-end
-
---- Test is file/dir is writable.
--- @param file string: filename to test
--- @return boolean: true if file exists, false otherwise.
-function is_writable(file)
-   assert(file)
-   local result
-   if is_dir(file) then
-      local file2 = file .. '/.tmpluarockstestwritable'
-      local fh = io.open(file2, 'w')
-      result = fh ~= nil
-      if fh then fh:close() end
-      os.remove(file2)
-   else
-      local fh = io.open(file, 'r+')
-      result = fh ~= nil
-      if fh then fh:close() end
-   end
-   return result
-end
-
-
---- Create a directory if it does not already exist.
--- If any of the higher levels in the path name does not exist
--- too, they are created as well.
--- @param d string: pathname of directory to create.
--- @return boolean: true on success, false on failure.
-function make_dir(d)
-   assert(d)
-   fs_execute("mkdir "..fs_Q(d).." 1> NUL 2> NUL")
-   return 1
-end
-
---- Remove a directory if it is empty.
--- Does not return errors (for example, if directory is not empty or
--- if already does not exist)
--- @param d string: pathname of directory to remove.
-function remove_dir_if_empty(d)
-   assert(d)
-   fs_execute_string("rmdir "..fs_Q(d).." 1> NUL 2> NUL")
-end
-
---- Copy a file.
--- @param src string: Pathname of source
--- @param dest string: Pathname of destination
--- @return boolean or (boolean, string): true on success, false on failure,
--- plus an error message.
-function copy(src, dest)
-   assert(src and dest)
-   if dest:match("[/\\]$") then dest = dest:sub(1, -2) end
-   if fs_execute("cp", src, dest) then
-      return true
-   else
-      return false, "Failed copying "..src.." to "..dest
-   end
-end
-
---- Recursively copy the contents of a directory.
--- @param src string: Pathname of source
--- @param dest string: Pathname of destination
--- @return boolean or (boolean, string): true on success, false on failure,
--- plus an error message.
-function copy_contents(src, dest)
-   assert(src and dest)
-   if fs_execute_string("cp -a "..src.."\\*.* "..fs_Q(dest).." 1> NUL 2> NUL") then
-      return true
-   else
-      return false, "Failed copying "..src.." to "..dest
-   end
-end
-
---- Delete a file or a directory and all its contents.
--- For safety, this only accepts absolute paths.
--- @param arg string: Pathname of source
--- @return boolean: true on success, false on failure.
-function delete(arg)
-   assert(arg)
-   assert(arg:match("^[\a-zA-Z]?:?[\\/]"))
-   fs_execute("chmod a+rw -R ", arg)
-   return fs_execute_string("rm -rf " .. fs_Q(arg) .. " 1> NUL 2> NUL")
-end
-
---- List the contents of a directory. 
--- @param at string or nil: directory to list (will be the current
--- directory if none is given).
--- @return table: an array of strings with the filenames representing
--- the contents of a directory.
-function list_dir(at)
-   assert(type(at) == "string" or not at)
-   if not at then
-      at = fs_current_dir()
-   end
-   if not fs_is_dir(at) then
-      return {}
-   end
-   local result = {}
-   local pipe = io.popen(command_at(at, "ls"))
-   for file in pipe:lines() do
-      table.insert(result, file)
-   end
-   pipe:close()
-
-   return result
-end
-
---- Recursively scan the contents of a directory. 
--- @param at string or nil: directory to scan (will be the current
--- directory if none is given).
--- @return table: an array of strings with the filenames representing
--- the contents of a directory. Paths are returned with forward slashes.
-function find(at)
-   assert(type(at) == "string" or not at)
-   if not at then
-      at = fs_current_dir()
-   end
-   if not fs_is_dir(at) then
-      return {}
-   end
-   local result = {}
-   local pipe = io.popen(command_at(at, "find 2> NUL")) 
-   for file in pipe:lines() do
-      -- Windows find is a bit different
-      if file:sub(1,2)==".\\" then file=file:sub(3) end
-      if file ~= "." then
-         table.insert(result, (file:gsub("\\", "/")))
-      end
-   end
-   return result
-end
-
-
---- Download a remote file.
--- @param url string: URL to be fetched.
--- @param filename string or nil: this function attempts to detect the
--- resulting local filename of the remote file as the basename of the URL;
--- if that is not correct (due to a redirection, for example), the local
--- filename can be given explicitly as this second argument.
--- @return boolean: true on success, false on failure.
-function download(url, filename)
-   assert(type(url) == "string")
-   assert(type(filename) == "string" or not filename)
-   local wget_cmd = "wget --user-agent="..cfg.user_agent.." --quiet --continue "
-
-   if filename then   
-      return fs_execute(wget_cmd.." --output-document ", filename, url)
-   else
-      return fs_execute(wget_cmd, url)
-   end
-end
-
 --- Strip the last extension of a filename.
 -- Example: "foo.tar.gz" becomes "foo.tar".
 -- If filename has no dots, returns it unchanged.
@@ -243,55 +33,6 @@ local function strip_extension(filename)
    return (filename:gsub("%.[^.]+$", "")) or filename
 end
 
---- Uncompress gzip file.
--- @param archive string: Filename of archive.
--- @return boolean : success status
-local function gunzip(archive)
-   local cmd = fs_execute("gunzip -h 1>NUL 2>NUL") and 'gunzip' or
-               fs_execute("gzip   -h 1>NUL 2>NUL") and 'gzip -d'
-   local ok = fs_execute(cmd, archive)
-   return ok
-end
-
---- Unpack an archive.
--- Extract the contents of an archive, detecting its format by
--- filename extension.
--- @param archive string: Filename of archive.
--- @return boolean or (boolean, string): true on success, false and an error message on failure.
-function unpack_archive(archive)
-   assert(type(archive) == "string")
-   
-   local ok
-   if archive:match("%.tar%.gz$") then
-      ok = gunzip(archive)
-      if ok then
-         ok = fs_execute("tar -xf ", strip_extension(archive))
-      end
-   elseif archive:match("%.tgz$") then
-      ok = gunzip(archive)
-      if ok then
-         ok = fs_execute("tar -xf ", strip_extension(archive)..".tar")
-      end
-   elseif archive:match("%.tar%.bz2$") then
-      ok = fs_execute("bunzip2 ", archive)
-      if ok then
-         ok = fs_execute("tar -xf ", strip_extension(archive))
-      end
-   elseif archive:match("%.zip$") then
-      ok = fs_execute("unzip ", archive)
-   elseif archive:match("%.lua$") or archive:match("%.c$") then
-      -- Ignore .lua and .c files; they don't need to be extracted.
-      return true
-   else
-      local ext = archive:match(".*(%..*)")
-      return false, "Unrecognized filename extension "..(ext or "")
-   end
-   if not ok then
-      return false, "Failed extracting "..archive
-   end
-   return true
-end
-
 --- Return an absolute pathname from a potentially relative one.
 -- @param pathname string: pathname to convert.
 -- @param relative_to string or nil: path to prepend when making
@@ -302,7 +43,7 @@ function absolute_name(pathname, relative_to)
    assert(type(pathname) == "string")
    assert(type(relative_to) == "string" or not relative_to)
 
-   relative_to = relative_to or fs_current_dir()
+   relative_to = relative_to or fs.current_dir()
    if pathname:match("^[\.a-zA-Z]?:?[\\/]") then
       return pathname
    else
@@ -344,7 +85,7 @@ function is_actual_binary(name)
 end
 
 function copy_binary(filename, dest) 
-   local ok, err = fs_copy(filename, dest)
+   local ok, err = fs.copy(filename, dest)
    if not ok then
       return nil, err
    end
diff --git a/src/luarocks/manif_core.lua b/src/luarocks/manif_core.lua
index 941c569d..d1eb4ebb 100644
--- a/src/luarocks/manif_core.lua
+++ b/src/luarocks/manif_core.lua
@@ -1,5 +1,6 @@
 
 --- Core functions for querying manifest files.
+-- This module requires no specific 'fs' functionality.
 module("luarocks.manif_core", package.seeall)
 
 local persist = require("luarocks.persist")
diff --git a/src/luarocks/tools/zip.lua b/src/luarocks/tools/zip.lua
index 621beae1..18ad967e 100644
--- a/src/luarocks/tools/zip.lua
+++ b/src/luarocks/tools/zip.lua
@@ -209,9 +209,9 @@ function zip(zipfile, ...)
 
    local ok, err
    for _, file in pairs({...}) do
-      if fs_is_dir(file) then
-         for _, file in pairs(fs_find(file)) do
-            if fs_is_file(file) then
+      if fs.is_dir(file) then
+         for _, file in pairs(fs.find(file)) do
+            if fs.is_file(file) then
                ok, err = add_to_zip(file)
                if not ok then break end
             end