From: Daniel Lezcano <daniel.lezcano@free.fr>
Date: Tue, 1 Feb 2011 10:42:29 +0000 (+0100)
Subject: lxc-attach gives a better error message
X-Git-Tag: lxc-0.7.4-rc1~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9f53d717c4fea7bb2a493d911da0abbe9c78aef5;p=thirdparty%2Flxc.git

lxc-attach gives a better error message

Don't assume the user knows the kernel internals :)

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
---

diff --git a/src/lxc/namespace.c b/src/lxc/namespace.c
index 3905a0333..3a6db795b 100644
--- a/src/lxc/namespace.c
+++ b/src/lxc/namespace.c
@@ -102,6 +102,12 @@ int lxc_attach(pid_t pid)
 	int fd[size];
 	int i;
 
+	sprintf(path, "/proc/%d/ns", pid);
+	if (access(path, R_OK)) {
+		ERROR("Does this kernel version support 'attach' ?");
+		return -1;
+	}
+
 	for (i = 0; i < size; i++) {
 		sprintf(path, "/proc/%d/ns/%s", pid, ns[i]);
 		fd[i] = open(path, O_RDONLY);