resolver.3: Mention that some functions set 'h_errno'

Reported-by: Wladimir Mutel <muwlgr@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man3/resolver.3 b/man3/resolver.3
index b50aa36118503c90b8181faf9d0aa315e11efa94..54c5d2f7e87e0215f8d104fe19d71e947a381cba 100644 (file)
--- a/man3/resolver.3
+++ b/man3/resolver.3
@@ -461,6 +461,20 @@ and
 .BR dn_expand ()
 functions return the length
 of the compressed name, or \-1 if an error occurs.
+.PP
+In the case of an error return from
+.BR res_nquery (),
+.BR res_query (),
+.BR res_nsearch (),
+.BR res_search (),
+.BR res_nquerydomain (),
+or
+.BR res_querydomain (),
+the global variable
+.I h_errno
+(see
+.BR gethostbyname (3))
+can be consulted to determine the cause of the error.
 .SH FILES
 .TP
 .I /etc/resolv.conf