How to use OpenSSL apart from generating SSL certificates.

Command line find/replace on files:

perl -p -i -e 's/old/new/g' `ack -l --html searchpattern`

sudo apt-get install ack-grep
For reference:

To jump to the beginning or end of a file (useful if it is really long as in an export of a SQL database) use the below shortcuts:

Beginning of file

ALT + \

End of file

ALT + /


In order to install an SSL certificate you need a couple of things.

To gzip a file while keeping a copy of the original file use the following command:

gzip -c -- file1.ext > file2.ext.gz

Also, you can define a shell function with the following code:

function gzipkeep {
if [ -f "$1" ] ; then
gzip -c -- "$1" > "$1.gz"
and then

gzipkeep file.txt

When binding custom classes for displaying in a datagridview the below link is quite helpful in providing sample code and details on setting up the column names and values.

When using VLCJ if you run into errors trying to play a media file you may need to use a playlist.

When any file gets played by VLC it is part of a playlist.  The playlist may have only one item in it, but the playlist is still kicking around in memory. 

If you get of the following errors when logging in via SSH you will likely also not be able to login with SFTP.  Read the full post for a fix.

id: cannot find name for user ID *** 
whoami: cannot find name for user ID *** 
grep: /var/cpanel/users/: Permission denied 
/usr/bin/whoami: cannot find name for user ID ***

To find the size of a specific directory use the following command.  If using / (root directory) you may need to run this using sudo.
du -chs /path/to/directory
-c - produces grand total
-h - human readable sizes (e.g. 1K, 25M, 3G)
-s - summarize (produces a total for each argument)
man du
for extra options

-- --
+ 3
-- xx