refs #4793 do not clear signal mask before execl() after fork() in sy…

…stem() to avoid crashes when the child is terminated by a signal

command-line.cpp

@@ -1,4 +1,4 @@
-/*
+ /*
     command-line.cpp
 
     Qore Programming Language

lib/ql_lib.qpp

@@ -91,7 +91,7 @@ extern bool threads_initialized;
 AbstractQoreNode* missing_function_error(const char* func, ExceptionSink* xsink) {
    QoreString have(func);
    have.toupr();
-   return xsink->raiseException("MISSING-FEATURE-ERROR", "this system does not implement %s(); for maximum portability use the constant Option::HAVE_%s to check if this function is implemented before calling", func, have.getBuffer());
+   return xsink->raiseException("MISSING-FEATURE-ERROR", "this system does not implement %s(); for maximum portability use the constant Option::HAVE_%s to check if this function is implemented before calling", func, have.c_str());
 }
 
 AbstractQoreNode* missing_function_error(const char* func, const char* opt, ExceptionSink* xsink) {
@@ -285,7 +285,7 @@ exec("/usr/bin/xterm -bg black -fg white -sb -sl 2000");
     @endcode
  */
 nothing exec(string command) [dom=EXTERNAL_PROCESS,PROCESS] {
-   ExecArgList exec_args(command->getBuffer());
+   ExecArgList exec_args(command->c_str());
    execvp(exec_args.getFile(), exec_args.getArgs());
 
    xsink->raiseErrnoException("EXEC-ERROR", errno, "execvp() failed in child process for target '%s'", exec_args.getFile());
@@ -310,31 +310,34 @@ int rc = system("ls -l");
  */
 int system(string command) [dom=EXTERNAL_PROCESS] {
 #if defined(HAVE_FORK) && defined(HAVE_SIGNAL_HANDLING)
-   // on platforms with fork(2) and signal handling, we need to fork, enable all signals, then execvp()
-   pid_t pid;
-   if (!(pid = fork())) {
-      // enable all signals
-      sigset_t mask;
-      sigemptyset(&mask);
-      sigprocmask(SIG_SETMASK, &mask, 0);
-
-      // exec pgm like system(): sh -c "command"
-      execl("/bin/sh", "sh", "-c", command->getBuffer(), NULL);
-      fprintf(stderr, "execvp() failed in child process for target '/bin/sh' with error code %d: %s\n", errno, strerror(errno));
-      _Exit(-1);
-      //qore_exit_process(-1);
-   }
-   if (pid == -1)
-      return -1;
-
-   // wait for child to exit
-   int status;
-   wait(&status);
-   return WIFEXITED(status) ? WEXITSTATUS(status) : -1;
+    // on platforms with fork(2) and signal handling, we need to fork, enable all signals, then execl()
+    pid_t pid;
+    if (!(pid = fork())) {
+        // exec pgm like system(): sh -c "command"
+        execl("/bin/sh", "sh", "-c", command->c_str(), NULL);
+        fprintf(stderr, "execl() failed in child process for target '/bin/sh' with error code %d: %s\n", errno,
+            strerror(errno));
+        _Exit(-1);
+        //qore_exit_process(-1);
+    }
+    if (pid == -1)
+        return -1;
+
+    // wait for child to exit
+    int status;
+    //wait(&status);
+    while (true) {
+        int rc = waitpid(pid, &status, WUNTRACED);
+        if (rc == -1 && errno == EINTR) {
+            continue;
+        }
+        break;
+    }
+    return WIFEXITED(status) ? WEXITSTATUS(status) : -1;
 #elif defined(HAVE_SYSTEM)
-   return system(command->getBuffer());
+    return system(command->c_str());
 #else
-   return missing_function_error("system", xsink);
+    return missing_function_error("system", xsink);
 #endif
 }
 
@@ -807,7 +810,7 @@ string fn = basename("/usr/local/bin/file_name");
     @see dirname()
  */
 string basename(string path) [flags=CONSTANT] {
-   char* p = q_basename(path->getBuffer());
+   char* p = q_basename(path->c_str());
    int len = strlen(p);
    return new QoreStringNode(p, len, len + 1, path->getEncoding());
 }
@@ -831,7 +834,7 @@ string dir = dirname("/usr/local/bin/file_name");
     @see basename()
  */
 string dirname(string path) [flags=CONSTANT] {
-   char* p = q_dirname(path->getBuffer());
+   char* p = q_dirname(path->c_str());
    int len = strlen(p);
    return new QoreStringNode(p, len, len + 1, path->getEncoding());
 }
@@ -964,7 +967,7 @@ if (!exists host)
     @see gethostbyname_long() for a version of this function that returns all host information, including all hostname aliases and all addresses
  */
 *string gethostbyname(string name) [flags=CONSTANT;dom=EXTERNAL_INFO] {
-   return q_gethostbyname_to_string(name->getBuffer());
+   return q_gethostbyname_to_string(name->c_str());
 }
 
 //! This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments
@@ -993,7 +996,7 @@ if (!exists hostname)
     @see gethostbyaddr_long() for a version of this function that returns all host information, including all hostname aliases and all addresses
  */
 *string gethostbyaddr(string addr, softint type = AF_INET) [flags=CONSTANT;dom=EXTERNAL_INFO] {
-   return q_gethostbyaddr_to_string(xsink, addr->getBuffer(), type);
+   return q_gethostbyaddr_to_string(xsink, addr->c_str(), type);
 }
 
 //! This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments
@@ -1018,7 +1021,7 @@ if (!ah)
     @see gethostbyname() for a version of this function that returns just the first network address corresponding to the hostname
  */
 *hash<auto> gethostbyname_long(string name) [flags=CONSTANT;dom=EXTERNAL_INFO] {
-   return q_gethostbyname_to_hash(name->getBuffer());
+   return q_gethostbyname_to_hash(name->c_str());
 }
 
 //! This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments
@@ -1047,7 +1050,7 @@ if (!ah)
     @see gethostbyaddr() for a simpler version of this function that returns just a single hostname for the address
  */
 *hash<auto> gethostbyaddr_long(string addr, softint type = AF_INET) [flags=CONSTANT;dom=EXTERNAL_INFO] {
-   return q_gethostbyaddr_to_hash(xsink, addr->getBuffer(), type);
+   return q_gethostbyaddr_to_hash(xsink, addr->c_str(), type);
 }
 
 //! This function variant does nothing at all; it is only included for backwards-compatibility with qore prior to version 0.8.0 for functions that would ignore type errors in arguments
@@ -1074,7 +1077,7 @@ list<hash<auto>> l = getaddrinfo("localhost");
     @throw QOREADDRINFO-GETINFO-ERROR nodename nor servname provided, or not known
  */
 list<hash<auto>> getaddrinfo(*string node, *softstring service, softint family = AF_UNSPEC, softint flags = 0) [flags=RET_VALUE_ONLY;dom=EXTERNAL_INFO] {
-   return q_getaddrinfo_to_list(xsink, node ? node->getBuffer() : 0, service ? service->getBuffer() : 0, (int)family, (int)flags);
+   return q_getaddrinfo_to_list(xsink, node ? node->c_str() : 0, service ? service->c_str() : 0, (int)family, (int)flags);
 }
 
 //! closes all possible file descriptors; useful in "daemon" processes that may have inherited open file descriptors