'luaL_execresult' does not assume -1 status as error
ISO C is silent about the return of 'system'. Windows sets 'errno' in
case of errors. Linux has several different error cases, with different
return values. ISO C allows 'system' to set 'errno' even if there are no
errors. Here we assume that a status==0 is success (which is the case
on several platforms), otherwise it is an error. If there is an error
number, gives the error based on it. (The worst a spurious 'errno'
can do is to generate a bad error message.) Otherwise uses the normal
results.
diff --git a/lauxlib.c b/lauxlib.c
index a5e9e4b..f2ba704 100644
--- a/lauxlib.c
+++ b/lauxlib.c
@@ -284,7 +284,7 @@
LUALIB_API int luaL_execresult (lua_State *L, int stat) {
const char *what = "exit"; /* type of termination */
- if (stat == -1) /* error? */
+ if (stat != 0 && errno != 0) /* error with an 'errno'? */
return luaL_fileresult(L, 0, NULL);
else {
l_inspectstat(stat, what); /* interpret result */
diff --git a/liolib.c b/liolib.c
index 08d1839..7ac3444 100644
--- a/liolib.c
+++ b/liolib.c
@@ -270,6 +270,7 @@
*/
static int io_pclose (lua_State *L) {
LStream *p = tolstream(L);
+ errno = 0;
return luaL_execresult(L, l_pclose(L, p->f));
}
diff --git a/loslib.c b/loslib.c
index 5e0fafb..e65e188 100644
--- a/loslib.c
+++ b/loslib.c
@@ -10,6 +10,7 @@
#include "lprefix.h"
+#include <errno.h>
#include <locale.h>
#include <stdlib.h>
#include <string.h>
@@ -138,10 +139,11 @@
-
static int os_execute (lua_State *L) {
const char *cmd = luaL_optstring(L, 1, NULL);
- int stat = system(cmd);
+ int stat;
+ errno = 0;
+ stat = system(cmd);
if (cmd != NULL)
return luaL_execresult(L, stat);
else {
