new file mode 100644
--- /dev/null
+++ b/lib/sig2str.h
@@ -0,0 +1,49 @@
+/* sig2str.h -- convert between signal names and numbers
+
+   Copyright (C) 2002 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Written by Paul Eggert.  */
+
+/* Include <signal.h> before including this file.  */
+
+/* Don't override system declarations of SIG2STR_MAX, sig2str, str2sig.  */
+#ifndef SIG2STR_MAX
+
+/* Upper bound on the string length of an integer converted to string.
+   302 / 1000 is ceil (log10 (2.0)).  Subtract 1 for the sign bit;
+   add 1 for integer division truncation; add 1 more for a minus sign.  */
+# define INT_STRLEN_BOUND(t) ((sizeof (t) * CHAR_BIT - 1) * 302 / 1000 + 2)
+
+/* Size of a buffer needed to hold a signal name like "HUP".  */
+# define SIG2STR_MAX (sizeof "SIGRTMAX" + INT_STRLEN_BOUND (int) - 1)
+
+int sig2str (int, char *);
+int str2sig (char const *, int *);
+
+#endif
+
+/* An upper bound on signal numbers allowed by the system.  */
+
+#if defined _sys_nsig
+# define SIGNUM_BOUND (_sys_nsig - 1)
+#elif defined NSIG
+# define SIGNUM_BOUND (NSIG - 1)
+#elif defined WTERMSIG
+# define SIGNUM_BOUND WTERMSIG (~ 0)
+#else
+# define SIGNUM_BOUND 127
+#endif