--- libelwix/src/pio.c	2013/12/05 15:04:20	1.1.2.2
+++ libelwix/src/pio.c	2013/12/05 15:38:14	1.1.2.4
@@ -26,6 +26,9 @@ e_popen(const char *command, const char *type, pid_t *
 	int pdes[2], pid, twoway, cloexec;
 	char *argv[4];
 
+	if (!command || !type)
+		return NULL;
+
 	cloexec = strchr(type, 'e') != NULL;
 	/*
 	 * Lite2 introduced two-way popen() pipes using _socketpair().
@@ -140,6 +143,9 @@ e_pclose(FILE *iop)
 	int pstat;
 	pid_t pid;
 
+	if (!iop)
+		return -1;
+
 	/*
 	 * Find the appropriate file pointer and remove it from the list.
 	 */
@@ -168,4 +174,60 @@ e_pclose(FILE *iop)
 	e_free(cur);
 
 	return (pid == -1 ? -1 : pstat);
+}
+
+/*
+ * pio_pgetpid() - Get tagPIOPID structure from file handle
+ *
+ * @iop = popen handle
+ * return: NULL error or !=NULL tagPIOPID structure
+ */
+struct tagPIOPID *
+pio_pgetpid(FILE * __restrict iop)
+{
+	struct tagPIOPID *p;
+
+	if (!iop)
+		return NULL;
+
+	THREAD_LOCK();
+	SLIST_FOREACH(p, &pio_pidlist, next)
+		if (p->fp == iop)
+			break;
+	THREAD_UNLOCK();
+
+	return p;
+}
+
+/*
+ * pio_pchkpid() - Check exit status of child programs
+ *
+ * @pids = return tagPIOPID structures of exited programs, 
+ * 		if !=NULL must call array_Destroy()
+ * return: -1 error or >-1 exited programs
+ */
+int
+pio_pchkpid(array_t ** __restrict pids)
+{
+	register int ret = 0;
+	struct tagPIOPID *p;
+	array_t *pa;
+
+	if (pids) {
+		if (!(pa = array_Init(0)))
+			return -1;
+		else
+			*pids = pa;
+	}
+
+	THREAD_LOCK();
+	SLIST_FOREACH(p, &pio_pidlist, next)
+		if (p->fp && waitpid(p->pid, &p->stat, WNOHANG) > 0) {
+			if (pids)
+				array_Push(pa, p, 0);
+			ret++;
+		}
+	THREAD_UNLOCK();
+
+	return ret;
 }