fchownat.2: AT_EMPTY_PATH is Linux-specific and requires _GNU_SOURCE

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man2/fchownat.2 b/man2/fchownat.2
index 96510939a8f021e7069a45be29c5f1d3f4196a1b..6b0c50471268be42c58e16a799206b7b15e7b5a2 100644 (file)
--- a/man2/fchownat.2
+++ b/man2/fchownat.2
@@ -106,6 +106,10 @@ flag).
 In this case,
 .I dirfd
 can refer to any type of file, not just a directory.
+This flag is Linux-specific; define
+.B _GNU_SOURCE
+.\" Before glibc 2.16, defining _ATFILE_SOURCE sufficed
+to obtain its definition.
 
 .TP
 .B AT_SYMLINK_NOFOLLOW