• Mac OS X,  Unix

    Mac OS X: lsof

    lsof is a command that can be used to list all the open files.  You can use grep to narrow down the listing to only those that match a certain string.

  • Active Directory,  Mac OS X Server,  Mac Security

    Managing the Keytab with ktutil

    clear_list – Clears the current keylist  read_kt or rkt – Reads a krb5 keytab into the current keylist  read_st or rst – Reads a krb4 srvtab into the current keylist  write_kt or wkt – Writes the current key listing into a krb5 keytab  write_st or wst – Writes the current key listing to a krb4 srvtab  add_entry or addent – Adds an entry to the current key listing  delete_entry, delent – Deletes an entry from the current key listing  list – Lists the current key listing  list_requests or lr – Lists available keys 

  • Mac OS X Server

    Kerberos Keys

    Kerberos uses keys to transmit information between hosts.  There are  session keys and service keys kept in the keytab file on the KDC.  The KDC (Key Distribution Center) then does out keys as needed.  To see the service keys: klist -k /etc/krb5.keytab

  • Mac OS X,  Mac OS X Server,  Ubuntu,  Unix

    Mac OS X: tail

    I was on the phone with someone earlier today and they didn’t realize that they could dynamically watch new lines come into log files in Mac OS X.  In order to do this you can use the tail command with the -f switch.  So if you want to watch your system.log file and run some processes you think will cause errors you can use the following command: tail -f system.log When you’re done watching the log file use the Control-C keystroke to stop.

  • Mac OS X,  Mac OS X Server,  Ubuntu,  Unix

    Pipes

    A pipe’s command redirection used in Mac OS X and other *nix operating systems to send the output of a program to another for further processing (known as redirection).  Redirection means transferring of a program to another destination, such as another program, file, or the monitor.  Standard output is sometimes abbreviated stdout.

  • Mac OS X,  Mac OS X Server,  Mac Security,  Ubuntu,  Unix

    ps

    Limit process listing to those belonging to a given user by piping the output through grep. For example, processes belonging to a user with a username charles can be displayed with the following: ps -ef | grep charles The -l option generates a long listing, and when used together with the -e and -f options creates a table with 15 columns, which can also be piped for the user name: ps -efl | grep charles