open.2: NOTES: mention existence of proc/PID/fd and /proc/PID/fdinfo

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

1 files changed, 11 insertions, 0 deletions

diff --git a/man2/open.2 b/man2/open.2
index 8bd31e0ff6..5e87cc71f5 100644
--- a/man2/open.2
+++ b/man2/open.2
@@ -1143,6 +1143,17 @@ flag, its
 and
 .I st_mtime
 fields are set to the current time.
+
+The files in the
+.I /proc/[pid]/fd
+directory show the open file descriptors of the process with the PID
+.IR pid .
+The files in the
+.I /proc/[pid]/fdinfo
+directory show even more information about these files descriptors.
+See
+.BR proc (5)
+for further details of both of these directories.
 .\"
 .\"
 .SS Open file descriptions