This is a useful packet grabber using tcpdump.
You don’t get as many details as wireshark or ethereal but running this on a remote server is easier.
First find out what network interface you want to capture.
$ ifconfigThen start capturing and write to a file with -w
$ tcpdump -i eth0 -w eth0-dump.log
You can then read the file with the -r switch
$ tcpdump -r eth0-dump.log
To change the system date/time in Linux create a symlink to /etc/localtime for the correct time zone.
Verify the new time with “date” then update the hardware clock with “hwclock”
$ ln -sf /usr/share/zoneinfo/America/Denver /etc/localtime $ date $ hwclock --systohc
You can also use ntpdate for NTP (Network Time Protocol)
$ ntpdate pool.ntp.org
$ hwclock --systohcYou will need to restart httpd to see this change reflected in your webserver.
Other Time Links
http://www.time.gov
Network Time Protocol
It is always useful to be able to automate backups. I found some of this out there in the ether and use it often.
#!/bin/bash dir="/var/www"; # what directory or file to back up cd ${dir} if [[ $? != 0 ]]; then #cd failed, we'll exit with an error message echo "Error: could not cd to ${dir}. No backup was created." exit 1; fi; # path to back up folder tar -zcf /var/www/backups/backup-$(date +%Y%m%d).tar.gz .
Go To: http://ftp.gnu.org/pub/gnu/
Browse for the app you are in need of, say wget, since this did not come on Mac OSX.
Download the tarball then unzip and install
1 2 3 4 5 | tar -xvzf wget-1.11.4.tar.gz cd wget-1.11.4 ./configure make sudo make install |
p.s. you may need tar also, if not, Stuffit will unzip, and make is included in the Apple XCode (~1.1GB)
I found this very useful, thanks to David Jameson and others.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | #!/bin/sh # create ssh connections without giving a password - found on the net # Modified by DHJ to correct several bugs and missing commands if [ $# -lt 1 ]; then echo Usage: $0 username@remotehost exit fi remote="$1" # 1st command-line argument is the user@remotehost address this=$HOST # name of client host # first check if we need to run ssh-keygen for generating # $HOME/.ssh with public and private keys: if [ ! -d $HOME/.ssh ]; then echo "just type RETURN for each question:" # no passphrase - unsecure!! # generate DSA keys only: echo; echo; echo #This will generate the .ssh directory and put the keys in it ssh-keygen -t dsa else # we have $HOME/.ssh, but check that we have # key (DSA): if [ ! -f $HOME/.ssh/id_dsa ]; then # generate DSA keys: echo "just type RETURN for each question:" # no passphrase - unsecure!! ssh-keygen -t dsa fi fi echo "You will be asked for your remote password several times during this phase" cd $HOME/.ssh if [ ! -f config ]; then # make ssh try ssh -2 (DSA keys) echo "Protocol 2" > config chmod 600 config fi #Make sure private key cannot be read by anyone else chmod 600 $HOME/.ssh/id_dsa # copy public keys to the destination host: echo; echo; echo # create .ssh on remote host if it's not there: echo "Connecting to remote host to create .ssh directory…" ssh $remote 'if [ ! -d .ssh ]; then mkdir .ssh; fi' # copy DSA key: echo "Copying public DSA key to remote host…" scp id_dsa.pub ${remote}:.ssh/${this}_dsa.pub # make authorized_keys(2) files on remote host: echo; echo; echo # this one copies DSA key: echo "Configuring authorized_keys2 file on remote host…" ssh $remote "cd .ssh; touch authorized_keys2; cat ${this}_dsa.pub >> authorized_keys2;" echo "Configuring directory permissions on remote host…" ssh $remote "cd .ssh; rm ${this}_dsa.pub; chmod 600 *; cd ..; chmod go-rwx .ssh;" echo; echo; echo echo "You should now be able to ssh to the remote host without a password" echo "try ssh $remote" |
Slashdot