If you have a large text file and want to quickly delete any duplicate lines, you can use the following option of sort in *nix..
sort -u filename > newfilename
If you want to get even funkier :), like only checking duplicates on a particular column, feel free to check out this link http://www.gnu.org/software/coreutils/manual/html_node/sort-invocation.html#sort-invocation.
Good link with information on configuring a custom transport link in Postfix. A transport link in a SMTP server is a way to define a communiction/delivery channel with particular settings. Example, you want all e-mails for a particular domain to be sent to a particular server at a particular time.
http://linuxnet.ca/postfix/dedicated_transport.html
In this particular link, the author shows the steps to configure a transport link for sending e-mails to servers/domains with high latency.
Simple and elegant script by a Bulgarian author (name unknown) for managing queues in Postfix.
If you need to edit documents, create spreadsheets and presentations… and don’t want to spend $$$ for Microsoft Office, download the latest version of OpenOffice for free and give it a try. You might be pleasantly surprised.
I wrote a post earlier about using OpenOffice as a free PDF Editor.. And that is just the tip of the iceberg of what you can do with OpenOffice.
Most of the people that use Microsoft Office, only use the basic functionality. As my old boss used to say, “95% of the people use 5% of the functionality in Office”. And switching to OpenOffice would be a breeze for then. OpenOffice is available for Microsoft Windows, Linux and Apple Mac OS X.
Since OpenOffice 3.0 was released back in October, the software has been downloaded more than 10 million times. And we are close to hitting 20 million downloads..Here’s a live counter from the OpenOffice website
If you ever wanted to search for a particular text in certain types of files in Linux, you can use the following combo of find and grep
find / -name \*.xml -type f | xargs grep -i “text_to_search”
I used *.xml (note the \ before *) as the mask in the filename to look for all XML files.. then I piped this to grep using xargs.
A colleague pointed out that I can do the same by using
grep -r o-i “text_to_speech”
Jboss, in addition to being an application server also serves static content. We recently ran into an issue where some static content was not displayed when users hit the link. The JBoss server kept spewing 404 errors, stating that the content was not found. On some hair pulling research, we figured out that JBoss, like Apache, does not follow/allow content mapped to a symbolic link.
So for example in your web app, you added a sym link to another directory, where most of your content is stored, Jboss would not show the content, when you go to the link.
Here’s a quick guide to fix this.
org.jboss.web.tomcat.security.RunAsListener
More information on options for the context.xml can be found here
http://www.jboss.org/file-access/default/members/jbossweb/freezone/docs/2.1.0/config/context.html
For the record, Jboss configuration and accompanying documentation is what I call black magic :).. Too many options, too many ways to do the same thing.
Simple how to for installing Wireshark, open source network capture/analysis tool on default install of Fedora 9.
Enjoy :)..
We recently launched a new product at work and had to optimize a Java web application hosted in a JBoss application server for performance. The following tools came in rather handy to troubleshoot and analyze the application.
<context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext*.xml,classpath:applicationContext*.xml</param-value> </context-param> <filter> <!-- MessAdmin Servlet Filter --> <filter-name>MessAdminFilter</filter-name> <filter-class>clime.messadmin.filter.MessAdminFilter</filter-class> </filter> <filter-mapping> <filter-name>MessAdminFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <listener> <!-- MessAdmin listener --> <listener-class>clime.messadmin.core.MessAdminListener</listener-class> </listener>
I recently came across a corrupted table in MySQL and was getting the following error, when I was trying to access a table.
“mysql ERROR 145 (HY000): Table ‘xxxxxxx’ is marked as crashed and should be repaired”
I repaired the table by
Love the simplicity of MySQL :).
If you want to search a file and show all the lines that don’t match a particular pattern, you an use the following option in grep
grep -v "PATTERN" fileName