Frequently Asked Questions About Linux / UNIX » Intermediate

OpenBSD: Mount An ISO Image Command

nixCraft — Thu, 16 May 2013 18:42:21 +0000

How do I mount an ISO image in OpenBSD operating systems using command line options?

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Ubuntu Linux: Install Latest Oracle Java 7

nixCraft — Thu, 16 May 2013 16:35:38 +0000

I am a network admin who recently made the switch from MS-Windows to Ubuntu Linux. I need to use Java and Firefox web browser plugin to run java applet. I am unable to access many devices such as Firewall appliance, LBS/VPX, and network equipments due to Ubuntu's incompatible openjdk and icedtea plugin. I also searched software center but unable to find Oracle Java 7. How do I install Oracle Java 7 and get rid of this incompatibility problems on Ubuntu Linux amd64 v12.04 LTS or v13.04+?

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Linux: Dell Laptop Fan Control And Get CPU Temperature

nixCraft — Thu, 16 May 2013 09:12:04 +0000

I have installed Debian or Ubuntu Linux on Dell Inspiron / Latitude / Precision / Vostro laptop. How do I see the current CPU temperature? How do I control and see fan status on Dell laptop?

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Ubuntu Linux: Install Google Chrome Browser Command

nixCraft — Fri, 10 May 2013 18:03:36 +0000

I am unable to find Google Chrome Browser in Ubuntu software center. How do I install Google Chrome in Ubuntu version 12.04 LTS or v13.04 using command line options?

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Debian / Ubuntu: Install gem The FrontEnd To Rubygems

nixCraft — Wed, 01 May 2013 16:55:18 +0000

How do I install rubygems package manager for Ruby on rails (RoR) under Debian or Ubuntu Linux operating systems?

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Debian Linux Install Eclipse Java / C / C++ IDE

nixCraft — Wed, 24 Apr 2013 10:00:42 +0000

How do I install Java and C/C++ integrated development environment called Eclipse under Debian GNU/Linux squeeze v6.xx?

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Linux: Turn On TCP SYN Cookie Protection

nixCraft — Sun, 14 Apr 2013 08:15:01 +0000

I am under DoS attack. My cloud based server hosting company asked me to enable TCP SYN cookie protection to save my domain from SYN Attack. How do I turn on TCP Syn cookie protection under Ubuntu or CentOS Linux based server?

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Apache / Nginx / Lighttpd: PHP Disable File Upload

nixCraft — Sun, 14 Apr 2013 07:31:55 +0000

I am in the process of setting Apache and PHP for my small business server. I'm not utilizing file upload functionality in any of my PHP scripts. How do I disallow uploading files under CentOS or Ubuntu Linux based LAMP server?

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Linux / Unix: Use rsync Command Over FTP

nixCraft — Tue, 09 Apr 2013 20:04:03 +0000

How do I use rsync command to sync files to a remote host called web-42.vps running VSFTPD ftp server? Can you give me rsync ftp example for Unix like operating systems?

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Linux: Force Close A Socket / Port On Server In a TIME_WAIT State

nixCraft — Tue, 09 Apr 2013 19:24:31 +0000

I run a BT client and few other server program on Linux. Sometime these programs get overloaded with too many connections and crashes. If I restart my apps, I see lots of old IPs in a TIME_WAIT state. How do I force and and close everything in a TIME_WAIT state under Linux operating systems?

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FreeBSD: Install sudo Command To Execute A Command As The Root

nixCraft — Tue, 19 Mar 2013 18:42:16 +0000

I have recently started to managing FreeBSD server along with Ubuntu Linux. However, sudo command, always shows me the following error:

zsh: command not found: sudo

How do I solve this problem and use sudo under FreeBSD 9.x system?

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Python Command Line Arguments Examples

nixCraft — Wed, 13 Mar 2013 22:47:18 +0000

I am a new Python programming user. I am working on user-friendly command-line interfaces, and I want to pass input via the shell args as follows: ./myscript.py filename ./myscript.py in.file output.file ./myscript.py -i in.file -o output.file How do I pass and parse command-line options and arguments using Python under Unix like operating systems?

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RHEL / CentOS: SELinux Is Preventing /sbin/iptables-multi-1.4.7 From Read Access On The File/rawip_socket

nixCraft — Sun, 10 Mar 2013 09:31:48 +0000

I upgraded my system to RHEL/CentOS v6.4 and I am getting the following error for 3rd party packages such as Shorewall and fail2ban:

Mar 10 03:43:56 b2 setroubleshoot: SELinux is preventing /sbin/iptables-multi-1.4.7 from read access on the file . For complete SELinux messages. run sealert -l dea027a2-81dd-4394-96d4-f0d1160c9307 Mar 10 03:43:56 b2 setroubleshoot: SELinux is preventing /sbin/iptables-multi-1.4.7 from create access on the rawip_socket . For complete SELinux messages. run sealert -l 08757ff1-a08d-4c06-a08b-ff5d53712305 Mar 10 03:43:56 b2 setroubleshoot: SELinux is preventing /sbin/iptables-multi-1.4.7 from read access on the file . For complete SELinux messages. run sealert -l dea027a2-81dd-4394-96d4-f0d1160c9307 Mar 10 03:43:56 b2 setroubleshoot: SELinux is preventing /sbin/iptables-multi-1.4.7 from create access on the rawip_socket . For complete SELinux messages. run sealert -l 08757ff1-a08d-4c06-a08b-ff5d53712305 Mar 10 03:43:56 b2 setroubleshoot: SELinux is preventing /sbin/iptables-multi-1.4.7 from read access on the file . For complete SELinux messages. run sealert -l dea027a2-81dd-4394-96d4-f0d1160c9307

How do I fix this problem?

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CentOS / RHEL v6.x: Install And Configure Serial Console

nixCraft — Mon, 25 Feb 2013 14:13:03 +0000

How do I configure serial console under CentOS Linux or Red Hat Enterprise Linux 6.x running on HP or Dell server?

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Linux: Find Out What Process Are Using Swap Space

nixCraft — Tue, 15 Jan 2013 19:59:19 +0000

The top and free command display the total amount of free and used physical and swap memory in the server. How do I determine which process is using swap space under Linux operating systems? How do I find out swap space usage of particular process such as memcached?

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Squid Proxy Server Change Outgoing IP Address

nixCraft — Tue, 15 Jan 2013 08:04:55 +0000

I have Squid caching proxy server deployed on Rackspace based server in UK. This server has four IP address. I would like to change outgoing IP addresses from default 1.2.3.1 to 1.2.3.4. How do I change proxy server outgoing IP address under Linux or Unix operating systems?

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OpenBSD: Configure Network Interface As A Bridge / Network Switch

nixCraft — Sun, 13 Jan 2013 13:00:17 +0000

I have Soekris single board communication embedded computers which is optimized for low power and network usage. The server has four Ethernet ports. How do I setup IPv4 software bridge using OpenBSD operating systems so that the rest of four ports act as a network switch?

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RHEL / Centos 6: Install Nginx Using Yum Command

nixCraft — Mon, 07 Jan 2013 07:26:19 +0000

How can I install Nginx web server On CentOS Linux 6 or Red Hat Enterprise Linux 6 using yum command?

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Linux Rename Eth0 Network Interface Card Name [ Udev ]

nixCraft — Tue, 01 Jan 2013 16:21:11 +0000

A wireless NIC is showing as wlan0 but I need to be appear as eth1. How can I rename wlan0 devices through udev as eth1? How do I change or rename eth0 as wan0 under Linux operating systems?

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Debian Linux: Configure Network Interfaces As A Bridge / Network Switch

nixCraft — Tue, 01 Jan 2013 15:52:50 +0000

My server has five Ethernet ports and one ADSL port. How do I setup IPv4 software bridge using Debian Linux operating systems so that the rest of five ports act as a network switch?

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