diff -Nru a2ps-4.15.6_copy/src/main.c a2ps-4.15.6/src/main.c
--- a2ps-4.15.6_copy/src/main.c	2025-02-28 17:57:05.292192000 +0800
+++ a2ps-4.15.6/src/main.c	2025-02-28 18:15:36.335386679 +0800
@@ -22,6 +22,7 @@
 /*                      I n c l u d e   f i l e s                       */
 /*                                                                      */
 /************************************************************************/
+#define _GNU_SOURCE 1
 #include <config.h>
 
 #include <signal.h>