fs: versions of exists, is_file, is_dir for Unix and Windows that do not fork

Implements versions of exists, is_file, is_dir for POSIX and Windows
using io.open only, based on the semantics of their error codes
on these platforms.

Drops the dependency on TEST.EXE on Windows.

9 files changed, 97 insertions, 53 deletions

diff --git a/install.bat b/install.bat
index a98b32fd..43b18e1d 100644
--- a/install.bat
+++ b/install.bat
@@ -67,8 +67,17 @@ local function exec(cmd)
 end

 

 local function exists(filename)

-        local cmd = [[.\win32\tools\test -e "]]..filename..[["]]

-        return exec(cmd)

+        local fd, _, code = io.open(filename, "r")

+        if code == 13 then

+                -- code 13 means "Permission denied" on both Unix and Windows

+                -- io.open on folders always fails with code 13 on Windows

+                return true

+        end

+        if fd then

+                fd:close()

+                return true

+        end

+        return false

 end

 

 local function mkdir (dir)

diff --git a/src/luarocks/core/cfg.lua b/src/luarocks/core/cfg.lua
index 670f04b2..5b9dec2f 100644
--- a/src/luarocks/core/cfg.lua
+++ b/src/luarocks/core/cfg.lua
@@ -242,7 +242,6 @@ local function make_defaults(lua_version, target_cpu, platforms, home)
          LS = "ls",
          RM = "rm",
          FIND = "find",
-         TEST = "test",
          CHMOD = "chmod",
          ICACLS = "icacls",
          MKTEMP = "mktemp",
@@ -718,7 +717,7 @@ function cfg.init(detected, warning)
    local defaults = make_defaults(lua_version, processor, platforms, cfg.home)
 
    if platforms.windows and hardcoded.WIN_TOOLS then
-      local tools = { "SEVENZ", "CP", "FIND", "LS", "MD5SUM", "PWD", "RMDIR", "TEST", "WGET", "MKDIR" }
+      local tools = { "SEVENZ", "CP", "FIND", "LS", "MD5SUM", "PWD", "RMDIR", "WGET", "MKDIR" }
       for _, tool in ipairs(tools) do
          defaults.variables[tool] = '"' .. hardcoded.WIN_TOOLS .. "/" .. defaults.variables[tool] .. '.exe"'
       end
diff --git a/src/luarocks/fs/lua.lua b/src/luarocks/fs/lua.lua
index 0976dc8d..6625ddda 100644
--- a/src/luarocks/fs/lua.lua
+++ b/src/luarocks/fs/lua.lua
@@ -590,6 +590,15 @@ function fs_lua.set_time(file, time)
    return lfs.touch(file, time)
 end
 
+else -- if not lfs_ok
+
+function fs_lua.exists(file)
+   assert(file)
+   file = dir.normalize(fs.absolute_name(file))
+   -- check if file exists by attempting to open it
+   return util.exists(file)
+end
+
 end
 
 ---------------------------------------------------------------------
diff --git a/src/luarocks/fs/unix.lua b/src/luarocks/fs/unix.lua
index 50bfba9c..849259e8 100644
--- a/src/luarocks/fs/unix.lua
+++ b/src/luarocks/fs/unix.lua
@@ -205,4 +205,44 @@ function unix._unix_moderate_permissions(perms)
    return moderated_perms
 end
 
+function unix.is_dir(file)
+   file = fs.absolute_name(file)
+   file = dir.normalize(file) .. "/"
+   local fd, _, code = io.open(file, "r")
+   if code == 2 then -- "No such file or directory"
+      return false
+   end
+   if code == 20 then -- "Not a directory", regardless of permissions
+      return false
+   end
+   if code == 13 then -- "Permission denied", but is a directory
+      return true
+   end
+   if fd then
+      fd:close()
+      return true
+   end
+   return false
+end
+
+function unix.is_file(file)
+   file = fs.absolute_name(file)
+   if fs.is_dir(file) then
+      return false
+   end
+   file = dir.normalize(file)
+   local fd, _, code = io.open(file, "r")
+   if code == 2 then -- "No such file or directory"
+      return false
+   end
+   if code == 13 then -- "Permission denied", but it exists
+      return true
+   end
+   if fd then
+      fd:close()
+      return true
+   end
+   return false
+end
+
 return unix
diff --git a/src/luarocks/fs/unix/tools.lua b/src/luarocks/fs/unix/tools.lua
index c5d83018..9a2f99a7 100644
--- a/src/luarocks/fs/unix/tools.lua
+++ b/src/luarocks/fs/unix/tools.lua
@@ -183,30 +183,6 @@ function tools.bunzip2(infile, outfile)
    return uncompress("bz2", "bunzip2", infile, outfile)
 end
 
---- Test is file/directory exists
--- @param file string: filename to test
--- @return boolean: true if file exists, false otherwise.
-function tools.exists(file)
-   assert(file)
-   return fs.execute(vars.TEST, "-e", 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 tools.is_dir(file)
-   assert(file)
-   return fs.execute(vars.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 tools.is_file(file)
-   assert(file)
-   return fs.execute(vars.TEST, "-f", file)
-end
-
 do
    local function rwx_to_octal(rwx)
       return (rwx:match "r" and 4 or 0)
diff --git a/src/luarocks/fs/win32.lua b/src/luarocks/fs/win32.lua
index 87232b77..498eceb7 100644
--- a/src/luarocks/fs/win32.lua
+++ b/src/luarocks/fs/win32.lua
@@ -234,6 +234,41 @@ function win32.replace_file(old_file, new_file)
    return os.rename(new_file, old_file)
 end
 
+function win32.is_dir(file)
+   file = fs.absolute_name(file)
+   file = dir.normalize(file)
+   local fd, _, code = io.open(file, "r")
+   if code == 13 then -- directories return "Permission denied"
+      fd, _, code = io.open(file .. "\\", "r")
+      if code == 2 then -- directories return 2, files return 22
+         return true
+      end
+   end
+   if fd then
+      fd:close()
+   end
+   return false
+end
+
+function win32.is_file(file)
+   file = fs.absolute_name(file)
+   file = dir.normalize(file)
+   local fd, _, code = io.open(file, "r")
+   if code == 13 then -- if "Permission denied"
+      fd, _, code = io.open(file .. "\\", "r")
+      if code == 2 then -- directories return 2, files return 22
+         return false
+      elseif code == 22 then
+         return true
+      end
+   end
+   if fd then
+      fd:close()
+      return true
+   end
+   return false
+end
+
 --- Test is file/dir is writable.
 -- Warning: testing if a file/dir is writable does not guarantee
 -- that it will remain writable and therefore it is no replacement
diff --git a/src/luarocks/fs/win32/tools.lua b/src/luarocks/fs/win32/tools.lua
index 77e962eb..f9468517 100644
--- a/src/luarocks/fs/win32/tools.lua
+++ b/src/luarocks/fs/win32/tools.lua
@@ -201,22 +201,6 @@ function tools.bunzip2(infile, outfile)
    return sevenz("bz2", infile, outfile)
 end
 
---- Test is pathname is a directory.
--- @param file string: pathname to test
--- @return boolean: true if it is a directory, false otherwise.
-function tools.is_dir(file)
-   assert(file)
-   return fs.execute_quiet("if not exist " .. fs.Q(file.."\\").." invalidcommandname")
-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 tools.is_file(file)
-   assert(file)
-   return fs.execute(vars.TEST.." -f", file)
-end
-
 --- Helper function for fs.set_permissions
 -- @return table: an array of all system users
 local function get_system_users()
@@ -292,14 +276,6 @@ function tools.set_permissions(filename, mode, scope)
    return true
 end
 
---- Test for existence of a file.
--- @param file string: filename to test
--- @return boolean: true if file exists, false otherwise.
-function tools.exists(file)
-   assert(file)
-   return fs.execute_quiet("if not exist " .. fs.Q(file) .. " invalidcommandname")
-end
-
 function tools.browser(url)
    return fs.execute(cfg.web_browser..' "Starting docs..." '..fs.Q(url))
 end
diff --git a/win32/COPYING b/win32/COPYING
index 3413b8c2..d28b2efd 100644
--- a/win32/COPYING
+++ b/win32/COPYING
@@ -5,7 +5,7 @@ following licenses:
 * For 7z.exe and 7z.dll, please see COPYING_7z for details.
 
 * find.exe, mv.exe, wget.exe, ls.exe, pwd.exe, rmdir.exe, md5sum.exe,
-  test.exe, cp.exe, mkdir.exe, and uname.exe are part of UnxUtils, check
+  cp.exe, mkdir.exe, and uname.exe are part of UnxUtils, check
   http://unxutils.sourceforge.net/ for license information.
 
 * Files under win32/lua5.1, except for Microsoft.VC80.CRT.manifest and msv*.*,
diff --git a/win32/tools/test.exe b/win32/tools/test.exe
deleted file mode 100644
index 94c95f9e..00000000
--- a/win32/tools/test.exe
+++ /dev/null