sighold, sigrelse, sigignore, sigset were available in XPG4.2.

diff --git a/signal/signal.h b/signal/signal.h
index 8263d3a..ded9a81 100644 (file)
--- a/signal/signal.h
+++ b/signal/signal.h
@@ -356,7 +356,7 @@ extern int sigaltstack (__const struct sigaltstack *__restrict __ss,
 
 #endif /* use BSD or X/Open Unix.  */
 
-#ifdef __USE_UNIX98
+#ifdef __USE_XOPEN_EXTENDED
 /* Simplified interface for signal management.  */
 
 /* Add SIG to the calling process' signal mask.  */