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

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

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.

Cmd Service Check Raw Output: Exim is not running

This is a bug in Exim
here are the steps how i fix this problem

Hello friends
you can doit by SSH
I first ran:

/scripts/eximup –force –source

I then removed the old exim RPM, which was preventing the correct one from

being updated.

I then ran:

/scripts/eximup –force

Exim is now up well.

Thank you.

< ?php
if ( strpos( $_SERVER['HTTP_USER_AGENT'], ‘Googlebot’ ) !== false )
{
// Your email address
$email_address = ‘you@yourdomain.com’;
// Send yourself an email
mail($email_address,’Googlebot Alert’, ‘The Googlebot has visited your page: ‘.$_SERVER['REQUEST_URI']);
}
?>

If you have any query feel free to contact me

pico /etc/motd

You will get a welcome screen you can modify it anything you want to show to your users. who logged via ssh. Write something like this
This computerized system is designed for registered users. All activity is recorded and investigated by the individual system regularly. Those without power or more than their rights when using this system to cancel all its services are subject to. Any illegal services or the user of the server or attempt to withdraw their services in the conduct of local law enforcement to notify the user of law will be finalized and will be punished. Anyone using this system consents to these terms.

Now type Ctrl+X then hit Y and enter

now your welcome message is now saved

Logout of SSH then log back in, you’ll see your new greeting..

To accomplish this you will need to edit the file .bash_profile.
At command prompt type the below command:

pico .bash_profile

At the end of the file add following code:

echo ‘ALERT – Root Access from:’ `date` `who` | mail -s “Alert: Root Access from `who | awk ‘{print $6}’`” admin@gmail.com

Replace this with your email “admin@gmail.com”

If  anybuddy login via ssh root  then you will recieve an email.

free

Mem is Ram size in bytes. Use -m option for output in MB.
SWAP is the size of SWAP partition.

free -m

Looks like you’re using up a lot of memory. Top displays your memory usage a little better as far as the “easy to read” factor goes.

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