sed tutorial and help

A very nice turorial and help <a href="http://sed.sourceforge.net/grabbag/tutorials/">here.

Useful link for grep

<a href="http://lifehacker.com/398441/get-to-know-grep">http://lifehacker.com/398441/get-to-know-grep

Viewing log files without using vi or any other text editor

This is quite useful for viewing files without opening them.. Saves quite a lot of time in viewing the logs 🙂

Want to see the first 5 lines of the /etc/passwd file? Pretty easy, just use the "head" command:

head -5 /etc/passwd

Want to see the last 20 lines of the /etc/passwd file? Again, pretty easy, just use the "tail" command:

tail -20 /etc/passwd

But what if you only want to see lines 10-15 of a given file? Neither the "head" nor the "tail" commands alone will do. Instead, use the "sed" command to print the range of lines you want to see:

View information on all the rpms installed.

This post if applicable to all the distro&#8217;s which are based on rpm.

If you look at the number of rpms installed on your system, you will see it somewhere around 500-2000. Noe thats a pretty huge number. So sometimes I keep wondering what are these rpms for. Heres a command that can help you figure out what these rpms are for:

rpm -qa –info

And if you want to find info on all the files and put it in a file too:

Browser and OS stats on my blog

I have been thinking of posting this for some time, but here are some stats from my <a class="zem_slink freebase/en/website" title="Website" rel="wikipedia" href="http://en.wikipedia.org/wiki/Website">website:

OS Stats :

<a href="http://blog.amit-agarwal.co.in/wp-content/uploads/2010/08/OS.jpg"><img class="size-full wp-image-1516" title="OS stats for blog.amit-agarwal.co.in" src="http://blog.amit-agarwal.co.in/wp-content/uploads/2010/08/OS.jpg" alt="OS stats for blog.amit-agarwal.co.in" width="429" height="311" />

Remove Invalid characters in Filename.

Sometimes I end up having some invalid characters in filename like ? & and so on.

So simple bash script to get rid of them:

for i in `find . -type f`
do
echo $i
mv $i `echo $i |tr ? _|tr = _ |tr &#8217;&&#8217; &#8217;_&#8217;`
done <a name="more">

Sendmail host map failure issue with sendmail.

I was having this issue for long time with sendmail and not getting time to fix this. Finally today I found the solution.
<span style="font-weight: bold;">define(`confBIND_OPTS&#8217;, `WorkAroundBrokenAAAA&#8217;)dnl
Add the above line in the sendmail.mc file and rebuild sendmail.cf.

Done. Quite simple but really took some time for me to fix.<span style="font-weight: bold;">
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