Manual pages: unshare.1: clarify that --pid=<file> requires --fork

Attempting to create a persistent PID namespace with --pid=<file>
will result in an error if --fork is not also specified. Let's
warn people about that, so they don't get puzzled.

Signed-off-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/unshare.1 b/sys-utils/unshare.1
index 443aac658b7924c8d6ff060701a6efb3631ed9c3..5292880afbee85129a534661f2ae26e815e6db0a 100644 (file)
--- a/sys-utils/unshare.1
+++ b/sys-utils/unshare.1
@@ -114,8 +114,13 @@ Unshare the network namespace.  If \fIfile\fP is specified, then a persistent
 namespace is created by a bind mount.
 .TP
 .BR \-p , " \-\-pid" [ =\fIfile ]
-Unshare the PID namespace.  If \fIfile\fP is specified then persistent
-namespace is created by a bind mount.  See also the \fB\-\-fork\fP and
+Unshare the PID namespace.  If \fIfile\fP is specified, then a persistent
+namespace is created by a bind mount.
+(Creation of a persistent PID namespace will fail if the
+.B \-\-fork
+option is not also specified.)
+.IP
+See also the \fB\-\-fork\fP and
 \fB\-\-mount-proc\fP options.
 .TP
 .BR \-u , " \-\-uts" [ =\fIfile ]