Add pidfile_fileno() to obtain the file descriptor for an open

pidfile.

1 files changed, 28 insertions, 2 deletions

diff --git a/lib/libutil/pidfile.3 b/lib/libutil/pidfile.3
index c42b95b..7ab9857 100644
--- a/lib/libutil/pidfile.3
+++ b/lib/libutil/pidfile.3
@@ -46,6 +46,8 @@
 .Fn pidfile_close "struct pidfh *pfh"
 .Ft int
 .Fn pidfile_remove "struct pidfh *pfh"
+.Ft int
+.Fn pidfile_fileno "struct pidfh *pfh"
 .Sh DESCRIPTION
 The
 .Nm pidfile
@@ -92,6 +94,10 @@ to start a child process.
 The
 .Fn pidfile_remove
 function closes and removes a pidfile.
+.Pp
+The
+.Fn pidfile_fileno
+function returns the file descriptor for the open pid file.
 .Sh RETURN VALUES
 The
 .Fn pidfile_open
@@ -105,15 +111,25 @@ If an error occurs,
 will be set.
 .Pp
 .Rv -std pidfile_write pidfile_close pidfile_remove
+.Pp
+The
+.Fn pidfile_fileno
+function returns the low-level file descriptor.
+It returns -1 and sets
+.Va errno
+if a NULL
+.Vt pidfh
+is specified, or if the pidfile is no longer open.
 .Sh EXAMPLES
 The following example shows in which order these functions should be used.
 Note that it is safe to pass
 .Dv NULL
 to
 .Fn pidfile_write ,
-.Fn pidfile_remove
-and
+.Fn pidfile_remove ,
 .Fn pidfile_close
+and
+.Fn pidfile_fileno
 functions.
 .Bd -literal
 struct pidfh *pfh;
@@ -244,6 +260,16 @@ and
 system calls and the
 .Xr flopen 3
 library function.
+.Pp
+The
+.Fn pidfile_fileno
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EDOOFUS
+Improper function use.
+Probably called not from the process which used
+.Fn pidfile_open .
+.El
 .Sh SEE ALSO
 .Xr open 2 ,
 .Xr daemon 3 ,