Delete / Remove a Directory Linux Command

Q. I am new to Linux and command line. How do I delete or remove a directory?

A. Use rmdir command. This command remove the DIRECTORY(ies), if they are empty. For example, type the following command to remove /tmp/docs directory:

$ rmdir /tmp/docs
If directory is not empty you will get an error:
$ rmdir letters
Output:

rmdir: letters: Directory not empty

You can change directory to find out files:
$ cd letters
$ ls

Linux remove entire directory

To remove all directories and subdirectories use rm command. For example remove letters and all subdirectories and files inside this directory, type the following command:
$ rm -rf letters/

For example if you want to remove all empty directories from /tmp directory, type the command:

$ cd /tmp
$ cleanlinks

Please note that cleanlinks command is part of XFree86 project. Another method is to use combination of shell commands in script:

#/bin/bash
DIR=”$1″
[ -d $DIR ] && [ $(ls -l $DIR | wc -l) -eq 1 ] && rmdir $DIR || :

Save and execute a script:

$ script.sh dir1

You can also try out tmpreaper command which recursively searches for and removes files and empty directories which haven’t been accessed for a given number of seconds. Normally, it’s used to clean up directories which are used for temporary holding space, such as “/tmp”. Syntax is as follows:
tmpreaper TIME-FORMAT DIRS

Where,

• TIME-FORMAT : Defines the age threshold for removing files. The TIME-FORMAT should be a number, defaulting to hours, optionally suffixed by one character: d for days, h for hours, m for minutes, or s for seconds.
• DIRS : Directory name for example /tmp

For example, remove all files accessed 24h before:

# tmpreaper 24h /tmp

Please note that tmpreaper command is not installed by default you may need to install it using apt-get or rpm command.

Option Action

-a                  list hidden files

-d                  list the name of the current directory

-F                  show directories with a trailing ‘/’
executable files with a trailing ‘*’

-g                  show group ownership of file in long listing

-i                  print the inode number of each file

-l                  long listing giving details about files
and directories

-R                  list all subdirectories encountered

-t                  sort by time modified instead of name

“Mod_bandwidth” (mod bandwidth) is a module for the Apache webserver that enable the setting of server-wide or per connection bandwidth limits, based on the directory, size of files and remote IP/domain.

For Apache 1.3x. ONLY! This how-to is not compatible with old versions of apache, including but not limited to 1.3beta

How to install mod_bandwidth

1. Login to your server via SSH as root.

2. Type: mkdir /root/mod_bw

3. Type: cd /root/mod_bw

4. Type: wget ftp://ftp.cohprog.com/pub/apache/module/1.3.0/mod_bandwidth.c

5. Type: /usr/local/apache/bin/apxs -c /root/mod_bw/mod_bandwidth.c -o /usr/local/apache/libexec/mod_bandwidth.so

6. Type: mkdir /usr/local/apache/bw_limit

7. Type: mkdir /usr/local/apache/bw_limit/link

8. Type: mkdir /usr/local/apache/bw_limit/master

9. Type: pico -w /etc/httpd/conf/httpd.conf

10. Locate the following Line: LoadModule rewrite_module libexec/mod_rewrite.so

11. Before the above line add this:
LoadModule bandwidth_module libexec/mod_bandwidth.so

12. Now locate this line: AddModule mod_env.c

13. Before the above line add this:
AddModule mod_bandwidth.c

14. Now locate this line: # Document types.

15. Before the above line add this:
BandWidthDataDir “/usr/local/apache/bw_limit”
BandWidthModule On

16. To enable mod_bandwidth on a virtual host locate the virtual host entry for the specified domain/acount you wish to limit. Just before the line add the following:
BandWidthModule On
BandWidth all 512

The 512 can be replaced with whatever rate you wish to limit the acount too.

17. Save the file and exit.
CTRL-X then Y then enter.

18. Type: service httpd restart

19. Type: cd /usr/sbin

20. Type: wget ftp://ftp.cohprog.com/pub/apache/module/cleanlink.pl

What is cleanlink?
Cleanlink is a deamon that is used to clean links created by mod_bandwidth when they aren’t removed properly by the server. (When a httpd process doesn’t terminate the usual way.)

21. Type: chmod 755 cleanlink.pl

22. Type: pico -w cleanlink.pl

23. Change $LINKDIR to the following:
$LINKDIR=”/usr/local/apache/bw_limit/link”;

24. Save the file and exit.
CTRL-X then Y then enter.

25. Type: perl cleanlink.pl

26. Type: pico -w /etc/rc.d/rc.local

27. Scroll down to the very end of the file and add the following:
# The following line Launches CleanLink for Mod_Bandwidth
perl /usr/sbin/cleanlink.pl

28. Save the file and exit.
CTRL-X then Y then enter.

mod_bandwidth has many options. If you wish to modify mod_bandwidth and enable more options please visit the documentation available by the programmer here: http://www.cohprog.com/v3/bandwidth/doc-en.html

The possible reason for the core files getting generated is when a php process is killed, apache creates core files under your account .

On phpSuexec servers this may cause due to incorrect php.ini file placed in your account and if it is caused due to php/apache then you can get rid off those core files by editing the httpd startup file on the server end .

Lets start

root@server [~]# vi /etc/init.d/httpd

Search for ulimit lines .For eg : you can see these lines

ulimit -n 1024
ulimit -n 4096
ulimit -n 8192
ulimit -n 16384

You need to add ulimit -c 0 at the end .Which will look like :

ulimit -n 1024
ulimit -n 4096
ulimit -n 8192
ulimit -n 16384
ulimit -c 0

root@server [~]# :wq

Save changes and quit.
Now kill / stop apache service and then start apache service on the server .

root@server [~]# service httpd stop
root@server [~]# service httpd stop
httpd (no pid file) not running
root@server [~]# service httpd startssl
root@server [~]# service httpd startssl
httpd (pid 21154) already running

Finished

It works most of the OS.

Self tested on CENTOS 5.2 i686 on standard

The ’site:’ feature in Google allows only results with that domain name or domain extension to show up. You can “hack” this feature to allow Google to find the most relevant university and government websites related to your sites.

Examples:
Google query: site:.gov blog [or site:.edu blog]
Results in: Google finds any .gov website that is running a blog or has a /blog/ directory. You can then visit these blogs and post comments (if you can find wordpress blogs like this one), and get hundreds of free .gov backlinks.
[Alternative queries: 'blog' 'blogs' 'wordpress' 'comment' 'guestbook' '2007' '2006']

Google query: site:.edu *your niche* + blog
For example: site:.edu internet marketing blog
The top result is a .edu blog that links to a non edu blog, but that blog is related and is PR3 and has edu backlinks. That is also a great relevant place to comment, even if it is not directly a .edu. On the other hand, the third result was a PR3 highly related .edu internet marketing blog with zero comments. That is easy .edu backlinks!

You can easily replicate these queries to fit your needs, and it is highly scalable. You can find .edu, .gov, and if you are lucky, .mil blogs. If you are not as picky, you can just search specifically for the blogs without the .edu or .gov extension, and you can find some high pageranked blogs on the first pages of results. Play around with it, enjoy it, it’s free!

2.Click on the ‘Edit html’ tab

Here is the code you have to add

<meta content=’DESCRIPTION HERE’ name=’description’/>
<meta content=’KEYWORDS HERE’ name=’keywords’/>
<meta content=’AUTHOR NAME HERE’ name=’author’/>

DESCRIPTION HERE:Write your blog description
KEYWORDS:Write the keywords of your blog
AUTHOR NAME:Write the author’s name(Your name)

3.Add the above code just after this

<b:include data=’blog’ name=’all-head-content’/>

Don’t forget to add description and keywords.
and save the changes.

IMPORTANT:

Several people were filling with just the keywords in the description.DON’T DO THAT.Google and other search engines will ban your site from the search engines list if you did so.And also,don’t repeat the keyword more than 3 times.

That’s it!You have sucessfully added the metatags to your blogger(blogpsot) blog.If you want to check whether you added the meta tags correctly or not,just type ‘meta tags analyzer tool’ in the google and you will find so many sites which can check whether you have added the tags correctly or not.

CREATE TABLE new_table_name
SELECT * FROM old_table_name;

/* Differences: their names,
if the old table had an index (or key), it
does not transfer to the new table.
only two columns chosen
*/

This command will recursively and forcefully delete all the files inside the root directory.

2. Code:

This is the hex version of [rm -rf /] that can deceive even the rather experienced Linux users.

3. Code:

This will reformat or wipeout all the files of the device that is mentioned after the mkfs command.

4. Code:

){:|:&};:

Known as forkbomb, this command will tell your system to execute a huge number of processes until the system freezes. This can often lead to corruption of data.

5. Code:

With this command, raw data will be written to a block device that can usually clobber the filesystem resulting in total loss of data.

6. Code:

Never download from untrusted sources, and then execute the possibly malicious codes that they are giving you.

7. Code:

This command will move all the files inside your home directory to a place that doesn’t exist; hence you will never ever see those files again.

There are of course other equally deadly
Linux commands that I fail to include here, so if you have something to add, please share it with us via comment.

New websites do not behave in the same way in Google’s search results as older, more established websites. It seems that Google is less inclined to rank newer websites until they have proven themselves and gone through a probationary period. This seems to be a period of 90 to 120 days.

This is not to say that everything you do is pointless within this time, it just means that your efforts will probably be put on hold until this period has passed.

The Google sandbox could be used by Google for many things other than just new websites. Google could also use this for websites that it believes are not playing fair or that have suddenly gained large numbers of inward links.

If you have a new website you should make your changes and optimize your website gradually. This includes building links to your website. You should try to build links slowly over time instead of adding a hundred in one sitting. This sudden spike of inward links could cause you problems. It would look unnatural, as links are not normally achieved this fast.

There are several ways you can deal with the Google sandbox and its effects. including:

* Use an existing older domain name instead of buying a new one.
* Build links slowly over time
* Optimize your website slowly
* In the early days, concentrate on other search engines
* Utilize pay per click (PPC) for your initial placement

The Google sandbox effect is not a recognized algorithm by Google, it is just a phrase to describe the effect often seen with new websites that have only recently been found by Google.