Add luaL_execresult to C API.

5 files changed, 55 insertions, 3 deletions

diff --git a/README.md b/README.md
index 93bc4c8..233f900 100644
--- a/README.md
+++ b/README.md
@@ -149,6 +149,7 @@ For Lua 5.1 additionally:
 * `luaL_setmetatable`
 * `luaL_getsubtable`
 * `luaL_traceback`
+* `luaL_execresult`
 * `luaL_fileresult`
 * `luaL_checkversion` (with empty body, only to avoid compile errors,
   see [here][20])
@@ -177,7 +178,6 @@ For Lua 5.1 additionally:
   * `lua_upvaluejoin` (5.1)
   * `lua_version` (5.1)
   * `lua_yieldk` (5.1)
-  * `luaL_execresult` (5.1)
   * `luaL_loadbufferx` (5.1)
   * `luaL_loadfilex` (5.1)
 
diff --git a/c-api/compat-5.3.c b/c-api/compat-5.3.c
index 962b951..0e06176 100644
--- a/c-api/compat-5.3.c
+++ b/c-api/compat-5.3.c
@@ -14,7 +14,7 @@
 
 
 /* definitions for Lua 5.1 only */
-#if defined( LUA_VERSION_NUM ) && LUA_VERSION_NUM == 501
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM == 501
 
 
 COMPAT53_API int lua_absindex (lua_State *L, int i) {
@@ -366,6 +366,44 @@ COMPAT53_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
     return 3;
   }
 }
+
+
+#if !defined(l_inspectstat) && \
+    (defined(unix) || defined(__unix) || defined(__unix__) || \
+     defined(__TOS_AIX__) || defined(_SYSTYPE_BSD))
+/* some form of unix; check feature macros in unistd.h for details */
+#  include <unistd.h>
+/* check posix version; the relevant include files and macros probably
+ * were available before 2001, but I'm not sure */
+#  if defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L
+#    include <sys/wait.h>
+#    define l_inspectstat(stat,what) \
+  if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \
+  else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; }
+#  endif
+#endif
+
+/* provide default (no-op) version */
+#if !defined(l_inspectstat)
+#  define l_inspectstat(stat,what) ((void)0)
+#endif
+
+
+COMPAT53_API int luaL_execresult (lua_State *L, int stat) {
+  const char *what = "exit";
+  if (stat == -1)
+    return luaL_fileresult(L, 0, NULL);
+  else {
+    l_inspectstat(stat, what);
+    if (*what == 'e' && stat == 0)
+      lua_pushboolean(L, 1);
+    else
+      lua_pushnil(L);
+    lua_pushstring(L, what);
+    lua_pushinteger(L, stat);
+    return 3;
+  }
+}
 #endif /* not COMPAT53_IS_LUAJIT */
 
 
diff --git a/c-api/compat-5.3.h b/c-api/compat-5.3.h
index dc8d3ea..cd6764c 100644
--- a/c-api/compat-5.3.h
+++ b/c-api/compat-5.3.h
@@ -45,7 +45,6 @@
  * lua_upvaluejoin
  * lua_version
  * lua_yieldk
- * luaL_execresult
  * luaL_loadbufferx
  * luaL_loadfilex
  */
@@ -150,6 +149,9 @@ COMPAT53_API void luaL_traceback (lua_State *L, lua_State *L1, const char *msg,
 
 #define luaL_fileresult COMPAT53_CONCAT(COMPAT53_PREFIX, L_fileresult)
 COMPAT53_API int luaL_fileresult (lua_State *L, int stat, const char *fname);
+
+#define luaL_execresult COMPAT53_CONCAT(COMPAT53_PREFIX, L_execresult)
+COMPAT53_API int luaL_execresult (lua_State *L, int stat);
 #endif /* COMPAT53_IS_LUAJIT */
 
 #define lua_callk(L, na, nr, ctx, cont) \
diff --git a/tests/test.lua b/tests/test.lua
index 856230b..f8fa894 100755
--- a/tests/test.lua
+++ b/tests/test.lua
@@ -700,5 +700,10 @@ print(pcall(mod.tolstring, t))
 
 ___''
 print(mod.buffer())
+
+___''
+print(mod.exec("exit 0"))
+print(mod.exec("exit 1"))
+print(mod.exec("exit 25"))
 ___''
 
diff --git a/tests/testmod.c b/tests/testmod.c
index f89b10a..c2dc715 100644
--- a/tests/testmod.c
+++ b/tests/testmod.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include <lua.h>
 #include <lauxlib.h>
 #include "compat-5.3.h"
@@ -256,6 +257,11 @@ static int test_buffer (lua_State *L) {
   return 1;
 }
 
+static int test_exec (lua_State *L) {
+  const char *cmd = luaL_checkstring(L, 1);
+  return luaL_execresult(L, system(cmd));
+}
+
 
 static const luaL_Reg funcs[] = {
   { "isinteger", test_isinteger },
@@ -277,6 +283,7 @@ static const luaL_Reg funcs[] = {
   { "globals", test_globals },
   { "tolstring", test_tolstring },
   { "buffer", test_buffer },
+  { "exec", test_exec },
   { NULL, NULL }
 };