add system.CODEPAGE_UTF8 for 65001 codepage

doc_topics/03-terminal.md

@@ -51,8 +51,8 @@ recent versions of Lua also have UTF-8 support. So `luasystem` also focusses on
 
 On Windows UTF-8 output can be enabled by setting the output codepage like this:
 
-    -- setup Windows output codepage to UTF-8; 65001
-    sys.setconsoleoutputcp(65001)
+    -- setup Windows output codepage to UTF-8
+    sys.setconsoleoutputcp(sys.CODEPAGE_UTF8)
 
 Terminal input is handled by the [`_getwchar()`](https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/getchar-getwchar) function on Windows which returns
 UTF-16 surrogate pairs. `luasystem` will automatically convert those to UTF-8.

examples/compat.lua

@@ -12,7 +12,7 @@ if sys.windows then
   os.getenv = sys.getenv  -- luacheck: ignore
 
   -- Set console output to UTF-8 encoding.
-  sys.setconsoleoutputcp(65001)
+  sys.setconsoleoutputcp(sys.CODEPAGE_UTF8)
 
   -- Set up the terminal to handle ANSI escape sequences on Windows.
   if sys.isatty(io.stdout) then

examples/readline.lua

@@ -442,7 +442,7 @@ local backup = sys.termbackup()
 sys.setconsoleflags(io.stdout, sys.getconsoleflags(io.stdout) + sys.COF_VIRTUAL_TERMINAL_PROCESSING)
 sys.setconsoleflags(io.stdin, sys.getconsoleflags(io.stdin) + sys.CIF_VIRTUAL_TERMINAL_INPUT)
 -- set output to UTF-8
-sys.setconsoleoutputcp(65001)
+sys.setconsoleoutputcp(sys.CODEPAGE_UTF8)
 
 -- setup Posix terminal to disable canonical mode and echo
 sys.tcsetattr(io.stdin, sys.TCSANOW, {

spec/04-term_spec.lua

@@ -8,7 +8,7 @@ describe("Terminal:", function()
 
   setup(function()
     wincodepage = system.getconsoleoutputcp()
-    assert(system.setconsoleoutputcp(65001))  -- set to UTF8
+    assert(system.setconsoleoutputcp(system.CODEPAGE_UTF8))  -- set to UTF8
   end)
 
   teardown(function()
@@ -346,8 +346,8 @@ describe("Terminal:", function()
       end)
 
       local new_cp
-      if old_cp ~= 65001 then
-        new_cp = 65001  -- set to UTF8
+      if old_cp ~= system.CODEPAGE_UTF8 then
+        new_cp = system.CODEPAGE_UTF8  -- set to UTF8
       else
         new_cp = 850    -- another common one
       end
@@ -403,8 +403,8 @@ describe("Terminal:", function()
       end)
 
       local new_cp
-      if old_cp ~= 65001 then
-        new_cp = 65001  -- set to UTF8
+      if old_cp ~= system.CODEPAGE_UTF8 then
+        new_cp = system.CODEPAGE_UTF8  -- set to UTF8
       else
         new_cp = 850    -- another common one
       end
@@ -578,8 +578,8 @@ describe("Terminal:", function()
 
       -- get the console page...
       local new_cp
-      if old_cp ~= 65001 then
-        new_cp = 65001  -- set to UTF8
+      if old_cp ~= system.CODEPAGE_UTF8 then
+        new_cp = system.CODEPAGE_UTF8  -- set to UTF8
       else
         new_cp = 850    -- another common one
       end

src/term.c

@@ -1042,7 +1042,7 @@ static int lst_getconsolecp(lua_State *L) {
 /***
 Sets the current console code page (Windows).
 @function setconsolecp
-@tparam int cp the code page to set, use 65001 for UTF-8
+@tparam int cp the code page to set, use `system.CODEPAGE_UTF8` (65001) for UTF-8
 @treturn[1] bool `true` on success (always `true` on Posix systems)
 */
 static int lst_setconsolecp(lua_State *L) {
@@ -1076,7 +1076,7 @@ static int lst_getconsoleoutputcp(lua_State *L) {
 /***
 Sets the current console output code page (Windows).
 @function setconsoleoutputcp
-@tparam int cp the code page to set, use 65001 for UTF-8
+@tparam int cp the code page to set, use `system.CODEPAGE_UTF8` (65001) for UTF-8
 @treturn[1] bool `true` on success (always `true` on Posix systems)
 */
 static int lst_setconsoleoutputcp(lua_State *L) {

system/init.lua

@@ -7,6 +7,11 @@
 local system = require 'system.core'
 
 
+--- UTF8 codepage.
+-- To be used with `system.setconsoleoutputcp` and `system.setconsolecp`.
+-- @field CODEPAGE_UTF8 The Windows CodePage for UTF8.
+system.CODEPAGE_UTF8 = 65001
+
 do
   local backup_mt = {}