This is really for my own benefit and quick reference. Here is the command to setup a local tunnel to a remote machine using ssh:
ssh -f -L [local-bind-address]:{local-port}:{endpoint-machine}:{endpoint-port} -N user@ssh-host
The options used:
-f – go into background before executing any commands
-L – For port forwarding [bind address:] local port : host : hostport
-N – Don’t run any commands on the remote SSH host, just set up the tunnel
The nice thing about this is that the endpoint machine can be different from the ssh host and the name used is in fact resolved by the remote ssh machine.
Ever accidentally change permissions on a filesystem and don’t know what it was before or how to get it back? Me too…
I was messing around with openSuSE the other day. I installed it on another partition on my hard drive. I mounted my Ubuntu partition and was just trying to copying some stuff over. In one of my dumbest moves I did something to the effect of chmod a+rwx /media/ubuntu, effectively screwing up all my permissions…I honestly don’t know what I was thinking.
Just recently I booted into my Ubuntu installation and noticed something weird when I logged it. It said that it couldn’t read some .dmrc file because of wrong permissions. I just fixed the problem and carried on. Then as I was trying to run a command with sudo it gave me the same error, that the permissions on /etc/sudoers was wrong. Good luck fixing that without a root password.
So I went back to openSuSE and wrote a little script that would fix the permissions as much as possible. I had another Ubuntu system that I mounted using sshfs and then basically searched for every file that existed locally on the remote machine and took the permissions from the remote machine’s files and copied them locally to fix the issue. Obviously it would not catch every file because I have different things installed on each but since they were both Ubuntu machines it came out close enough.
So here is the script I used, hopefully it will be of help:
#/usr/bin/env python
import os, stat, sys
def get_perms(path):
st = os.stat(path)
mode = st[stat.ST_MODE]
return mode & 07777
def set_perms(frompath, topath):
os.chmod(topath, get_perms(frompath))
if __name__ == "__main__":
print "copying perms to %s" % sys.argv[1]
print "looking for similar files in %s" % sys.argv[2]
if raw_input("do you wish to continue? ").lower() == "y":
for root, dirs, files in os.walk(sys.argv[1]):
for f in files+dirs:
topath = os.path.join(root, f)
frompath = topath.replace(sys.argv[1], sys.argv[2], 1)
print "doing %s -> %s" % (frompath, topath)
if os.path.islink(topath):
print "file %s is a link, skipping" % topath
continue
if not os.path.exists(frompath):
print "file %s does not exist to copy perms from" % frompath
continue
#print "frompath %s, perms %o" % (frompath, get_perms(frompath))
#print "topath before to %s, perms %o" % (topath, get_perms(topath))
set_perms(frompath, topath)
#print "frompath %s, perms %o" % (frompath, get_perms(frompath))
#print "topath after to %s, perms %o" % (topath, get_perms(topath))
I was just playing around with different feed readers lately. I enjoy Akregator because it gives me all the options I need and probably the feature that I like the most is that it displays the number of unread items in the system tray and can be minimized to the tray as well.
I have installed Akregator on my machine at work and everything was working great. I installed it on my laptop and was having a problem that showed a message ‘Unable to load storage backend plugin “metakit”. No feeds are archived’ and all feeds were marked as unread even though it had previously been read.
Found a fix that was pretty simple. Just run kbuildsyscocoa from the command line and start it up again. Works like a charm.
