Add the ability to retrieve the exit code of the forked AGI process. If there

is an error executing the AGI script, or the AGI script itself returns a
non-zero value, the AGISTATUS variable will now be set to FAILURE instead of
SUCCESS.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@30328 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/app.h

@@ -119,6 +119,27 @@ int ast_app_messagecount(const char *context, const char *mailbox, const char *f
 */
 int ast_safe_system(const char *s);
 
+/*!
+ * \brief Replace the SIGCHLD handler
+ *
+ * Normally, Asterisk has a SIGCHLD handler that is cleaning up all zombie
+ * processes from forking elsewhere in Asterisk.  However, if you want to
+ * wait*() on the process to retrieve information about it's exit status,
+ * then this signal handler needs to be temporaraly replaced.
+ *
+ * Code that executes this function *must* call ast_unreplace_sigchld()
+ * after it is finished doing the wait*().
+ */
+void ast_replace_sigchld(void);
+
+/*!
+ * \brief Restore the SIGCHLD handler
+ *
+ * This function is called after a call to ast_replace_sigchld.  It restores
+ * the SIGCHLD handler that cleans up any zombie processes.
+ */
+void ast_unreplace_sigchld(void);
+
 /*!
   \brief Send DTMF to a channel