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.

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

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.

* Login to SSH as root using a program like putty.
* Type the following command,

/scripts/restartsrv_mysql

Hope you all enjoy this command.

<?php
$ip = getenv(“REMOTE_ADDR”) ;
Echo “Your IP is ” . $ip;
?>

and save it with any name like file.php

$ mysql -u root –p

Output:

Enter password:

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 16 to server version: 4.1.15-Debian_1-log
Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the buffer.

mysql>

Now setup cache size 32Mb:
mysql> SET GLOBAL query_cache_size = 33554432;    

Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE 'query_cache_size';

Output:

+——————+———-+

| Variable_name | Value |

+——————+———-+

| query_cache_size | 16777216 |

+——————+———-+

You can setup them in /etc/my.cnf (Red Hat) or /etc/mysql/my.cnf (Debian) file:
# vi /etc/my.cnf
Append config directives as follows:

query_cache_size = 33554432
query_cache_type=1
query_cache_limit=2096576

http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe

1. Download it on your pc.
2. Double-click on the putty.exe program to open.
3. Next fill in the appropriate SSH settings for your service:

Putty

Next fill in the appropriate SSH settings for your service:

Host Name:

1. • 

     Host name

     • (gs) Grid-Service – s#####.gridserver.com or mt-example.com
     • (dv) Dedicated-Virtual -mt-example.com or xxx.xxx.xxx.xxx
     • (ss) Shared-Server – mt-example.com or xxx.xxx.xxx.xxx
   • Port: 22
     

     port 22

   • Connection Type: SSH
     

     Connection Type

   • Next click Open to start the SSH Connection:
   

   putty open

   Once the SSH Connection is open you should see a terminal prompt saying login as: Please provide your full username:

Login Screen

1. • (gs) Grid-Service – The default should be serveradmin@mt-example.com, however you may also login as username@mt-example.com.

     NOTE:

     Please make sure SSH is enabled for the user. SSH can be enabled from within the (ac) AccountCenter.

   • (dv) Dedicated-Virtual – You may login as the root user, or as a domain’s FTP user which has SSH access enabled
   • Next provide your password. Please note that you will not see any typing such as *** when providing your password. Once you hit enter you should now be connected to your service.

   Common SSH Command

Install Skype API Plugin for Pidgin in Ubuntu

First you need to download the plugin using the following command

wget http://eion.robbmob.com/skype4pidgin.deb

Now you should have skype4pidgin.deb package.Install this .deb package using the following command

sudo dpkg -i skype4pidgin.deb

or you can download the following libskype.so file to the plugins directory, normally /usr/lib/purple-2/ or ~/.purple/plugins

For 32 bit users download this

wget http://eion.robbmob.com/libskype.so

For 64 bit users download this

wget http://eion.robbmob.com/libskype64.so

This will complete the installation.After installation you need to restart Pidgin! You will then have a skype option enabled.

corkscrew is a simple tool to tunnel TCP connections through an HTTP proxy supporting the CONNECT method. It reads stdin and writes to stdout during the connection, just like netcat.

It can be used for instance to connect to an SSH server running on a remote 443 port through a strict HTTPS proxy.

Install corkscrew in ubuntu using the following command

sudo aptitude install corkscrew

This will complete the installation.

Configue corkscrew

If your HTTP proxy uses authentication, then you’ll need to tell it about the username and password to use This is where the concept of ‘auth-file’ comes into play. All you have to do is put your username & password, separated by a colon, into a textfile. Once you’ve done this, you just have to tell corkscrew where to find the auth-file. Create a file called .corkscrew-auth in your home directory

$touch .corkscrew-auth

$gedit .corkscrew-auth

and place your username and password in the following format

username:password

Save and exit the file.

Configure ssh For Tunneling

Now we’ll tell ssh what to do when connecting to all or specific hosts. Open up ~/.ssh/config (that’s /home/yourusername/.ssh/config) in your favourite text editor (gedit,nano,vim etc)

$gedit /home/yourusername/.ssh/config

and add the following lines

Host *

ProxyCommand corkscrew proxyhostname proxyport %h %p /home/username/.corkscrew-auth

Save and exit the file

Note: replace proxyhostname and proxyport with the equivalents for your network.

Note: you won’t need to add the last section, ‘/home/username/.corkscrew-auth’, if your HTTP proxy doesn’t use authentication.

What we’ve just told ssh to do is for all hostnames (’Host *’), use the following proxy command to route the connection.If you want more secure connections you can also list of hosts.

Corkscrew Syntax

corkscrew proxy proxyport targethost targetport [ authfile ]

proxy – This is the name of the host running the HTTP proxy.

proxyport – This is the port on which to connect on the proxy.

target – This is the host to reach through the proxy.

targetport – This is the port to connect to on the target host.

Test your SSH connection

ssh serverip