Merge pull request #561 from mpeterv/common-fs-tools-funcs

Move common `luarocks.fs.{unix,win32}.tools` functions into a new module

6 files changed, 194 insertions, 302 deletions

diff --git a/src/luarocks/fs.lua b/src/luarocks/fs.lua
index 57302c7f..f3d86a13 100644
--- a/src/luarocks/fs.lua
+++ b/src/luarocks/fs.lua
@@ -68,7 +68,10 @@ load_fns(fs_lua)
 
 -- 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
+if ok and fs_plat_tools then
+   load_fns(fs_plat_tools)
+   load_fns(require("luarocks.fs.tools"))
+end
 
 
 return fs
diff --git a/src/luarocks/fs/tools.lua b/src/luarocks/fs/tools.lua
new file mode 100644
index 00000000..ed51b545
--- /dev/null
+++ b/src/luarocks/fs/tools.lua
@@ -0,0 +1,156 @@
+
+--- Common fs operations implemented with third-party tools.
+local tools = {}
+
+local fs = require("luarocks.fs")
+local dir = require("luarocks.dir")
+local cfg = require("luarocks.cfg")
+
+local vars = cfg.variables
+
+local dir_stack = {}
+
+--- Obtain current directory.
+-- Uses the module's internal directory stack.
+-- @return string: the absolute pathname of the current directory.
+function tools.current_dir()
+   local current = cfg.cache_pwd
+   if not current then
+      local pipe = io.popen(fs.quiet_stderr(fs.Q(vars.PWD)))
+      current = pipe:read("*l")
+      pipe:close()
+      cfg.cache_pwd = current
+   end
+   for _, directory in ipairs(dir_stack) do
+      current = fs.absolute_name(directory, current)
+   end
+   return current
+end
+
+--- Change the current directory.
+-- Uses the module's internal directory 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 directory string: The directory to switch to.
+-- @return boolean or (nil, string): true if successful, (nil, error message) if failed.
+function tools.change_dir(directory)
+   assert(type(directory) == "string")
+   if fs.is_dir(directory) then
+      table.insert(dir_stack, directory)
+      return true
+   end
+   return nil, "directory not found: "..directory
+end
+
+--- Change directory to root.
+-- Allows leaving a directory (e.g. for deleting it) in
+-- a crossplatform way.
+function tools.change_dir_to_root()
+   table.insert(dir_stack, "/")
+end
+
+--- Change working directory to the previous in the directory stack.
+function tools.pop_dir()
+   local directory = table.remove(dir_stack)
+   return directory ~= nil
+end
+
+--- Run the given command.
+-- The command is executed in the current directory in the directory stack.
+-- @param cmd string: No quoting/escaping is applied to the command.
+-- @return boolean: true if command succeeds (status code 0), false
+-- otherwise.
+function tools.execute_string(cmd)
+   local current = fs.current_dir()
+   if not current then return false end
+   cmd = fs.command_at(current, cmd)
+   local code = os.execute(cmd)
+   if code == 0 or code == true then
+      return true
+   else
+      return false
+   end
+end
+
+--- Internal implementation function for fs.dir.
+-- Yields a filename on each iteration.
+-- @param at string: directory to list
+-- @return nil
+function tools.dir_iterator(at)
+   local pipe = io.popen(fs.command_at(at, fs.Q(vars.LS)))
+   for file in pipe:lines() do
+      if file ~= "." and file ~= ".." then
+         coroutine.yield(file)
+      end
+   end
+   pipe:close()
+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, string): true and the filename on success,
+-- false and the error message on failure.
+function tools.use_downloader(url, filename, cache)
+   assert(type(url) == "string")
+   assert(type(filename) == "string" or not filename)
+
+   filename = fs.absolute_name(filename or dir.base_name(url))
+
+   local ok
+   if cfg.downloader == "wget" then
+      local wget_cmd = fs.Q(vars.WGET).." "..vars.WGETNOCERTFLAG.." --no-cache --user-agent=\""..cfg.user_agent.." via wget\" --quiet "
+      if cfg.connection_timeout and cfg.connection_timeout > 0 then
+        wget_cmd = wget_cmd .. "--timeout="..tonumber(cfg.connection_timeout).." --tries=1 "
+      end
+      if cache then
+         -- --timestamping is incompatible with --output-document,
+         -- but that's not a problem for our use cases.
+         fs.change_dir(dir.dir_name(filename))
+         ok = fs.execute_quiet(wget_cmd.." --timestamping ", url)
+         fs.pop_dir()
+      elseif filename then
+         ok = fs.execute_quiet(wget_cmd.." --output-document ", filename, url)
+      else
+         ok = fs.execute_quiet(wget_cmd, url)
+      end
+   elseif cfg.downloader == "curl" then
+      local curl_cmd = fs.Q(vars.CURL).." "..vars.CURLNOCERTFLAG.." -f -L --user-agent \""..cfg.user_agent.." via curl\" "
+      if cfg.connection_timeout and cfg.connection_timeout > 0 then
+        curl_cmd = curl_cmd .. "--connect-timeout "..tonumber(cfg.connection_timeout).." "
+      end
+      ok = fs.execute_string(fs.quiet_stderr(curl_cmd..fs.Q(url).." > "..fs.Q(filename)))
+   end
+   if ok then
+      return true, filename
+   else
+      return false
+   end
+end
+
+local md5_cmd = {
+   md5sum = fs.Q(vars.MD5SUM),
+   openssl = fs.Q(vars.OPENSSL).." md5",
+   md5 = fs.Q(vars.MD5),
+}
+
+--- Get the MD5 checksum for a file.
+-- @param file string: The file to be computed.
+-- @return string: The MD5 checksum or nil + message
+function tools.get_md5(file)
+   local cmd = md5_cmd[cfg.md5checker]
+   if not cmd then return nil, "no MD5 checker command configured" end
+   local pipe = io.popen(cmd.." "..fs.Q(fs.absolute_name(file)))
+   local computed = pipe:read("*a")
+   pipe:close()
+   if computed then
+      computed = computed:match("("..("%x"):rep(32)..")")
+   end
+   if computed then return computed end
+   return nil, "Failed to compute MD5 hash for file "..tostring(fs.absolute_name(file))
+end
+
+return tools
diff --git a/src/luarocks/fs/unix.lua b/src/luarocks/fs/unix.lua
index e2cc825b..520b3e99 100644
--- a/src/luarocks/fs/unix.lua
+++ b/src/luarocks/fs/unix.lua
@@ -16,6 +16,13 @@ function unix.quiet(cmd)
    return cmd.." 1> /dev/null 2> /dev/null"
 end
 
+--- Annotate command string for execution with quiet stderr.
+-- @param cmd string: A command-line string.
+-- @return string: The command-line, with stderr silencing annotation.
+function unix.quiet_stderr(cmd)
+   return cmd.." 2> /dev/null"
+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
diff --git a/src/luarocks/fs/unix/tools.lua b/src/luarocks/fs/unix/tools.lua
index ab55897e..84bd53fd 100644
--- a/src/luarocks/fs/unix/tools.lua
+++ b/src/luarocks/fs/unix/tools.lua
@@ -7,74 +7,16 @@ local fs = require("luarocks.fs")
 local dir = require("luarocks.dir")
 local cfg = require("luarocks.cfg")
 
-local dir_stack = {}
-
 local vars = cfg.variables
 
-local function command_at(directory, cmd)
+--- Adds prefix to command to make it run from a directory.
+-- @param directory string: Path to a directory.
+-- @param cmd string: A command-line string.
+-- @return string: The command-line with prefix.
+function tools.command_at(directory, cmd)
    return "cd " .. fs.Q(fs.absolute_name(directory)) .. " && " .. cmd
 end
 
---- Obtain current directory.
--- Uses the module's internal directory stack.
--- @return string: the absolute pathname of the current directory.
-function tools.current_dir()
-   local current = cfg.cache_pwd
-   if not current then
-      local pipe = io.popen(fs.Q(vars.PWD).." 2> /dev/null")
-      current = pipe:read("*l")
-      pipe:close()
-      cfg.cache_pwd = current
-   end
-   for _, directory in ipairs(dir_stack) do
-      current = fs.absolute_name(directory, current)
-   end
-   return current
-end
-
---- Run the given command.
--- The command is executed in the current directory in the directory stack.
--- @param cmd string: No quoting/escaping is applied to the command.
--- @return boolean: true if command succeeds (status code 0), false
--- otherwise.
-function tools.execute_string(cmd)
-   local current = fs.current_dir()
-   if not current then return false end
-   local code, err = os.execute(command_at(current, cmd))
-   if code == 0 or code == true then
-      return true
-   else
-      return false
-   end
-end
-
---- Change the current directory.
--- Uses the module's internal directory 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 directory string: The directory to switch to.
-function tools.change_dir(directory)
-   assert(type(directory) == "string")
-   if fs.is_dir(directory) then
-      table.insert(dir_stack, directory)
-      return true
-   end
-   return nil, "directory not found: "..directory
-end
-
---- Change directory to root.
--- Allows leaving a directory (e.g. for deleting it) in
--- a crossplatform way.
-function tools.change_dir_to_root()
-   table.insert(dir_stack, "/")
-end
-
---- Change working directory to the previous in the directory stack.
-function tools.pop_dir()
-   local directory = table.remove(dir_stack)
-   return directory ~= 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.
@@ -155,20 +97,6 @@ function tools.delete(arg)
    fs.execute_quiet(vars.RM, "-rf", arg)
 end
 
---- Internal implementation function for fs.dir.
--- Yields a filename on each iteration.
--- @param at string: directory to list
--- @return nil
-function tools.dir_iterator(at)
-   local pipe = io.popen(command_at(at, vars.LS))
-   for file in pipe:lines() do
-      if file ~= "." and file ~= ".." then
-         coroutine.yield(file)
-      end
-   end
-   pipe:close()
-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).
@@ -183,7 +111,7 @@ function tools.find(at)
       return {}
    end
    local result = {}
-   local pipe = io.popen(command_at(at, vars.FIND.." * 2>/dev/null"))
+   local pipe = io.popen(fs.command_at(at, fs.quiet_stderr(vars.FIND.." *")))
    for file in pipe:lines() do
       table.insert(result, file)
    end
@@ -232,51 +160,6 @@ function tools.is_file(file)
    return fs.execute(vars.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, string): true and the filename on success,
--- false and the error message on failure.
-function tools.use_downloader(url, filename, cache)
-   assert(type(url) == "string")
-   assert(type(filename) == "string" or not filename)
-
-   filename = fs.absolute_name(filename or dir.base_name(url))
-
-   local ok
-   if cfg.downloader == "wget" then
-      local wget_cmd = fs.Q(vars.WGET).." "..vars.WGETNOCERTFLAG.." --no-cache --user-agent='"..cfg.user_agent.." via wget' --quiet "
-      if cfg.connection_timeout and cfg.connection_timeout > 0 then
-        wget_cmd = wget_cmd .. "--timeout="..tonumber(cfg.connection_timeout).." --tries=1 " 
-      end
-      if cache then
-         -- --timestamping is incompatible with --output-document,
-         -- but that's not a problem for our use cases.
-         fs.change_dir(dir.dir_name(filename))
-         ok = fs.execute_quiet(wget_cmd.." --timestamping ", url)
-         fs.pop_dir()
-      elseif filename then
-         ok = fs.execute_quiet(wget_cmd.." --output-document ", filename, url)
-      else
-         ok = fs.execute_quiet(wget_cmd, url)
-      end
-   elseif cfg.downloader == "curl" then
-      local curl_cmd = fs.Q(vars.CURL).." "..vars.CURLNOCERTFLAG.." -f -L --user-agent '"..cfg.user_agent.." via curl' "
-      if cfg.connection_timeout and cfg.connection_timeout > 0 then
-        curl_cmd = curl_cmd .. "--connect-timeout "..tonumber(cfg.connection_timeout).." " 
-      end
-      ok = fs.execute_string(curl_cmd..fs.Q(url).." 2> /dev/null 1> "..fs.Q(filename))
-   end
-   if ok then
-      return true, filename
-   else
-      return false
-   end
-end
-
 function tools.chmod(pathname, mode)
    if mode then 
       return fs.execute(vars.CHMOD, mode, pathname)
@@ -319,28 +202,6 @@ function tools.unpack_archive(archive)
    return true
 end
 
-local md5_cmd = {
-   md5sum = vars.MD5SUM,
-   openssl = vars.OPENSSL.." md5",
-   md5 = vars.MD5,
-}
-
---- Get the MD5 checksum for a file.
--- @param file string: The file to be computed.
--- @return string: The MD5 checksum
-function tools.get_md5(file)
-   local cmd = md5_cmd[cfg.md5checker]
-   if not cmd then return nil, "no MD5 checker command configured" end
-   local pipe = io.popen(cmd.." "..fs.Q(fs.absolute_name(file)))
-   local computed = pipe:read("*a")
-   pipe:close()
-   if computed then
-      computed = computed:match("("..("%x"):rep(32)..")")
-   end
-   if computed then return computed end
-   return nil, "Failed to compute MD5 hash for file "..tostring(fs.absolute_name(file))
-end
-
 function tools.get_permissions(filename)
    local pipe = io.popen(vars.STAT.." "..vars.STATFLAG.." "..fs.Q(filename))
    local ret = pipe:read("*l")
diff --git a/src/luarocks/fs/win32.lua b/src/luarocks/fs/win32.lua
index c14c421b..74f3ed69 100644
--- a/src/luarocks/fs/win32.lua
+++ b/src/luarocks/fs/win32.lua
@@ -27,6 +27,13 @@ function win32.quiet(cmd)
    return cmd.." 2> NUL 1> NUL"
 end
 
+--- Annotate command string for execution with quiet stderr.
+-- @param cmd string: A command-line string.
+-- @return string: The command-line, with stderr silencing annotation.
+function win32.quiet_stderr(cmd)
+   return cmd.." 2> NUL"
+end
+
 local drive_letter = "[%.a-zA-Z]?:?[\\/]"
 
 local win_escape_chars = {
diff --git a/src/luarocks/fs/win32/tools.lua b/src/luarocks/fs/win32/tools.lua
index b9dce85c..9cb6d47a 100644
--- a/src/luarocks/fs/win32/tools.lua
+++ b/src/luarocks/fs/win32/tools.lua
@@ -9,22 +9,13 @@ local fs = require("luarocks.fs")
 local dir = require("luarocks.dir")
 local cfg = require("luarocks.cfg")
 
-local dir_stack = {}
-
 local vars = cfg.variables
 
---- Strip the last extension of a filename.
--- Example: "foo.tar.gz" becomes "foo.tar".
--- If filename has no dots, returns it unchanged.
--- @param filename string: The file name to strip.
--- @return string: The stripped name.
-local function strip_extension(filename)
-   assert(type(filename) == "string")
-
-   return (filename:gsub("%.[^.]+$", "")) or filename
-end
-
-local function command_at(directory, cmd)
+--- Adds prefix to command to make it run from a directory.
+-- @param directory string: Path to a directory.
+-- @param cmd string: A command-line string.
+-- @return string: The command-line with prefix.
+function tools.command_at(directory, cmd)
    local drive = directory:match("^([A-Za-z]:)")
    cmd = "cd " .. fs.Q(directory) .. " & " .. cmd
    if drive then
@@ -33,68 +24,6 @@ local function command_at(directory, cmd)
    return cmd
 end
 
---- Obtain current directory.
--- Uses the module's internal directory stack.
--- @return string: the absolute pathname of the current directory.
-function tools.current_dir()
-   local current = cfg.cache_pwd
-   if not current then
-      local pipe = io.popen(fs.Q(vars.PWD).. " 2> NUL")
-      current = pipe:read("*l")
-      pipe:close()
-      cfg.cache_pwd = current
-   end
-   for _, directory in ipairs(dir_stack) do
-      current = fs.absolute_name(directory, current)
-   end
-   return current
-end
-
---- Run the given command.
--- The command is executed in the current directory in the directory stack.
--- @param cmd string: No quoting/escaping is applied to the command.
--- @return boolean: true if command succeeds (status code 0), false
--- otherwise.
-function tools.execute_string(cmd)
-   local current = fs.current_dir()
-   if not current then return false end
-   cmd = command_at(current, cmd)
-   local code = os.execute(cmd)
-   if code == 0 or code == true then
-      return true
-   else
-      return false
-   end
-end
-
---- Change the current directory.
--- Uses the module's internal directory 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 directory string: The directory to switch to.
--- @return boolean or (nil, string): true if successful, (nil, error message) if failed.
-function tools.change_dir(directory)
-   assert(type(directory) == "string")
-   if fs.is_dir(directory) then
-      table.insert(dir_stack, directory)
-      return true
-   end
-   return nil, "directory not found: "..directory
-end
-
---- Change directory to root.
--- Allows leaving a directory (e.g. for deleting it) in
--- a crossplatform way.
-function tools.change_dir_to_root()
-   table.insert(dir_stack, "/")
-end
-
---- Change working directory to the previous in the directory stack.
-function tools.pop_dir()
-   local directory = table.remove(dir_stack)
-   return directory ~= 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.
@@ -168,20 +97,6 @@ function tools.delete(arg)
    fs.execute_quiet("if exist "..fs.Q(arg.."\\").." ( RMDIR /S /Q "..fs.Q(arg).." ) else ( DEL /Q /F "..fs.Q(arg).." )")
 end
 
---- Internal implementation function for fs.dir.
--- Yields a filename on each iteration.
--- @param at string: directory to list
--- @return nil
-function tools.dir_iterator(at)
-   local pipe = io.popen(command_at(at, fs.Q(vars.LS)))
-   for file in pipe:lines() do
-      if file ~= "." and file ~= ".." then
-         coroutine.yield(file)
-      end
-   end
-   pipe:close()
-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).
@@ -196,7 +111,7 @@ function tools.find(at)
       return {}
    end
    local result = {}
-   local pipe = io.popen(command_at(at, fs.Q(vars.FIND).." 2> NUL"))
+   local pipe = io.popen(fs.command_at(at, fs.quiet_stderr(fs.Q(vars.FIND))))
    for file in pipe:lines() do
       -- Windows find is a bit different
       local first_two = file:sub(1,2)
@@ -242,49 +157,14 @@ function tools.is_file(file)
    return fs.execute(fs.Q(vars.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, string): true and the filename on success,
--- false and the error message on failure.
-function tools.use_downloader(url, filename, cache)
-   assert(type(url) == "string")
-   assert(type(filename) == "string" or not filename)
-
-   filename = fs.absolute_name(filename or dir.base_name(url))
-
-   local ok   
-   if cfg.downloader == "wget" then
-      local wget_cmd = fs.Q(vars.WGET).." "..vars.WGETNOCERTFLAG.." --no-cache --user-agent=\""..cfg.user_agent.." via wget\" --quiet "
-      if cfg.connection_timeout and cfg.connection_timeout > 0 then
-        wget_cmd = wget_cmd .. "--timeout="..tonumber(cfg.connection_timeout).." --tries=1 " 
-      end
-      if cache then
-         -- --timestamping is incompatible with --output-document,
-         -- but that's not a problem for our use cases.
-         fs.change_dir(dir.dir_name(filename))
-         ok = fs.execute_quiet(wget_cmd.." --timestamping ", url)
-         fs.pop_dir()
-      elseif filename then
-         ok = fs.execute_quiet(wget_cmd.." --output-document ", filename, url)
-      else
-         ok = fs.execute_quiet(wget_cmd, url)
-      end
-   elseif cfg.downloader == "curl" then
-      local curl_cmd = fs.Q(vars.CURL).." "..vars.CURLNOCERTFLAG.." -f -L --user-agent \""..cfg.user_agent.." via curl\" "
-      if cfg.connection_timeout and cfg.connection_timeout > 0 then
-        curl_cmd = curl_cmd .. "--connect-timeout "..tonumber(cfg.connection_timeout).." " 
-      end
-      ok = fs.execute_string(curl_cmd..fs.Q(url).." 2> NUL 1> "..fs.Q(filename))
-   end
-   if ok then
-      return true, filename
-   else
-      return false
-   end
+--- Strip the last extension of a filename.
+-- Example: "foo.tar.gz" becomes "foo.tar".
+-- If filename has no dots, returns it unchanged.
+-- @param filename string: The file name to strip.
+-- @return string: The stripped name.
+local function strip_extension(filename)
+   assert(type(filename) == "string")
+   return (filename:gsub("%.[^.]+$", "")) or filename
 end
 
 --- Uncompress gzip file.
@@ -334,28 +214,6 @@ function tools.unpack_archive(archive)
    return true
 end
 
-local md5_cmd = {
-   md5sum = fs.Q(vars.MD5SUM),
-   openssl = fs.Q(vars.OPENSSL).." md5",
-   md5 = fs.Q(vars.MD5),
-}
-
---- Get the MD5 checksum for a file.
--- @param file string: The file to be computed.
--- @return string: The MD5 checksum or nil + message
-function tools.get_md5(file)
-   local cmd = md5_cmd[cfg.md5checker]
-   if not cmd then return nil, "no MD5 checker command configured" end
-   local pipe = io.popen(cmd.." "..fs.Q(fs.absolute_name(file)))
-   local computed = pipe:read("*a")
-   pipe:close()
-   if computed then
-      computed = computed:match("("..("%x"):rep(32)..")")
-   end
-   if computed then return computed end
-   return nil, "Failed to compute MD5 hash for file "..tostring(fs.absolute_name(file))
-end
-
 --- Test for existance of a file.
 -- @param file string: filename to test
 -- @return boolean: true if file exists, false otherwise.