nixCraft » Shell scripting http://www.cyberciti.biz/tips This is a Linux sys admin journal by Vivek about sys admin work, Linux tips & tricks, hacks, news and more. Wed, 24 Apr 2013 18:50:55 +0000 en-US hourly 1 http://wordpress.org/?v=3.5.1 Shell Script Wrapper Examples: Enhance the Ping and Host Commandshttp://www.cyberciti.biz/tips/unix-linux-bash-shell-script-wrapper-examples.html http://www.cyberciti.biz/tips/unix-linux-bash-shell-script-wrapper-examples.html#comments Tue, 19 Jun 2012 13:20:08 +0000 nixCraft http://www.cyberciti.biz/tips/?p=9155 Shell script wrappers can make the *nix command more transparent to the user. The most common shell scripts are simple wrappers around third party or system binaries. A wrapper is nothing but a shell script that includes a system command or utility. Linux and Unix like operating system can run both 32bit and 64bit specific versions of applications. You can write a wrapper script that can select and execute correct version on a 32bit or 64bit hardware platform. In cluster environment and High-Performance computing environment you may find 100s of wrapper scripts written in Perl, Shell, and Python to get cluster usage, setting up shared storage, submitting and managing jobs, backups, troubleshooting, invokes commands with specified arguments, sending stdout to stdout and stderr to stderr and much more. In this post, I will explains how to create a shell wrapper to enhance the basic troubleshooting tool such as ping and host.]]> http://www.cyberciti.biz/tips/unix-linux-bash-shell-script-wrapper-examples.html/feed 11 30 Handy Bash Shell Aliases For Linux / Unix / Mac OS Xhttp://www.cyberciti.biz/tips/bash-aliases-mac-centos-linux-unix.html http://www.cyberciti.biz/tips/bash-aliases-mac-centos-linux-unix.html#comments Mon, 11 Jun 2012 05:58:51 +0000 nixCraft http://www.cyberciti.biz/tips/?p=9063 An alias is nothing but shortcut to commands. The alias command allows user to launch any command or group of commands (including options and filenames) by entering a single word. Use alias command to display list of all defined aliases. You can add user defined aliases to ~/.bashrc file. You can cut down typing time with these aliases, work smartly, and increase productivity at the command prompt. ]]> http://www.cyberciti.biz/tips/bash-aliases-mac-centos-linux-unix.html/feed 73 HowTo: Use Bash Parameter Substitution Like A Prohttp://www.cyberciti.biz/tips/bash-shell-parameter-substitution-2.html http://www.cyberciti.biz/tips/bash-shell-parameter-substitution-2.html#comments Wed, 13 Oct 2010 22:32:02 +0000 nixCraft http://www.cyberciti.biz/tips/?p=7409 The $ character is used for parameter expansion, and command substitution. You can use it for manipulating and/or expanding variables on demands without using external commands such as sed or awk. ]]> http://www.cyberciti.biz/tips/bash-shell-parameter-substitution-2.html/feed 17 10 Tools To Add Some Spice To Your UNIX Shell Scriptshttp://www.cyberciti.biz/tips/spice-up-your-unix-linux-shell-scripts.html http://www.cyberciti.biz/tips/spice-up-your-unix-linux-shell-scripts.html#comments Mon, 19 Apr 2010 20:47:43 +0000 nixCraft http://www.cyberciti.biz/tips/?p=6787 There are some misconceptions that shell scripts are only for a CLI environment. You can easily use various tools to write GUI and/or network (socket) scripts under KDE or Gnome desktops. Shell scripts can make use of some of the GUI widget (menus, warning boxs, progress bars etc). You can always control the final output, cursor position on screen, various output effects, and so on. With the following tools you can build powerful, interactive, user friendly UNIX / Linux bash shell scripts.]]> http://www.cyberciti.biz/tips/spice-up-your-unix-linux-shell-scripts.html/feed 95 Linux x86_64: Detecting Hardware Errorshttp://www.cyberciti.biz/tips/linux-server-predicting-hardware-failure.html http://www.cyberciti.biz/tips/linux-server-predicting-hardware-failure.html#comments Tue, 02 Jun 2009 21:54:58 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4951 The Blue Screen of Death (BSoD) is used for the error screen displayed by Microsoft Windows, after encountering a critical system. Linux / UNIX like operating system may get a kernel panic. It is just like BSoD. The BSoD and a kernel panic generated using a Machine Check Exception (MCE). MCE is nothing but feature of AMD / Intel 64 bit systems which is used to detect an unrecoverable hardware problem.

Program such mcelog decodes machine check events (hardware errors) on x86-64 machines running a 64-bit Linux kernel. It should be run regularly as a cron job on any x86-64 Linux system. This is useful for predicting server hardware failure before actual server crash.]]> http://www.cyberciti.biz/tips/linux-server-predicting-hardware-failure.html/feed 7 Poll: Your Favorite Scripting Language?http://www.cyberciti.biz/tips/poll-your-favorite-scripting-language.html http://www.cyberciti.biz/tips/poll-your-favorite-scripting-language.html#comments Tue, 17 Mar 2009 18:40:23 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4552 Like most sys admin, I'm lazy. I try to automate almost all things in order to save time. Inexperienced sys admin and help desk staff working under me finds all these tools useful. It saves their time and avoids security issues. Automation allows help desk staff to do things that they don't have enough direct system knowledge to do themselves. However, selecting correct tool and applying correct methodology is very important.

Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.]]> http://www.cyberciti.biz/tips/poll-your-favorite-scripting-language.html/feed 36 Debunking the "Linux is virus free" Mythhttp://www.cyberciti.biz/tips/debunking-the-linux-is-virus-free-myth.html http://www.cyberciti.biz/tips/debunking-the-linux-is-virus-free-myth.html#comments Wed, 11 Feb 2009 20:46:10 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4420 Is Linux is virus free? The author of foobar blog provides some insight about the same. Linux users can't just catch a virus by email or downloading malware from the Internet, contrary to "those Windows users". From the foobar blog post:
Then you save an email attachment under Linux, the execute flag is normally NOT set and thus, the file can't be executed just by clicking on it. So, no luck?
]]> http://www.cyberciti.biz/tips/debunking-the-linux-is-virus-free-myth.html/feed 21 How To Write Object-Oriented Shell scripts For Multiple Platformshttp://www.cyberciti.biz/tips/squirrel-portable-shell-and-scripting-language.html http://www.cyberciti.biz/tips/squirrel-portable-shell-and-scripting-language.html#comments Mon, 19 Jan 2009 06:42:27 +0000 nixCraft http://www.cyberciti.biz/tips/?p=4559 This may come handy while writing cross-platform scripts.

If you don't want to commit to the idiosyncrasies of a specific shell running on a particular platform, try the Squirrel Shell. The Squirrel Shell provides an advanced, object-oriented scripting language that works equally well on UNIX, Linux, Mac OS X, and Windows systems. Write a script once, and run it anywhere.

Squirrel is a high level imperative/OO programming language, designed to be a light-weight scripting language that fits in the size, memory bandwidth, and real-time requirements of applications like video games.

=> Speaking UNIX: The Squirrel portable shell and scripting language]]> http://www.cyberciti.biz/tips/squirrel-portable-shell-and-scripting-language.html/feed 0 Upgrade WordPress 2.7 in 3 Simple Stepshttp://www.cyberciti.biz/tips/howto-upgrade-wordpress-27-using-shellprompt.html http://www.cyberciti.biz/tips/howto-upgrade-wordpress-27-using-shellprompt.html#comments Thu, 11 Dec 2008 09:48:04 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3927 Wordpress version 2.7 has been released and can be upgraded easily using UNIX / Linux shell prompt. A few assumptions:
  1. Wordpress database name: wptheosblog
  2. Wordpress directory name: /var/www/html/theos.in
  3. Wordpress domain name: theos.in
  4. Operating system: Linux
WARNING! If you are not comfortable with UNIX shell prompt (IF YOU ARE new to a UNIX/Linux os), please follow traditional way of upgrading wordpress and DO NOT use the three Steps described here.
]]> http://www.cyberciti.biz/tips/howto-upgrade-wordpress-27-using-shellprompt.html/feed 3 Linux / UNIX: Find Out If a Directory Exists or Nothttp://www.cyberciti.biz/tips/find-out-if-directory-exists.html http://www.cyberciti.biz/tips/find-out-if-directory-exists.html#comments Sun, 16 Nov 2008 17:13:15 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3560 I've already written a small tutorial about finding out if a file exists or not under Linux / UNIX bash shell. However, couple of our regular readers like to know more about a directory checking using if and test shell command. ]]> http://www.cyberciti.biz/tips/find-out-if-directory-exists.html/feed 4 How To Use vi as Default Editor and Viewer in Midnight Commanderhttp://www.cyberciti.biz/tips/midnightcommander-set-vi-as-default-editor-viewer.html http://www.cyberciti.biz/tips/midnightcommander-set-vi-as-default-editor-viewer.html#comments Mon, 03 Nov 2008 05:01:50 +0000 nixCraft http://www.cyberciti.biz/tips/?p=3361 Midnight Commander (mc) is an user-friendly text-based file manager UI for Unix. Using mc, you can browse the filesystem easily and manipulate the files and directories quickly. You will not miss the standard command line prompt, which is also available within the mc itself. If you are new to mc, Midnight Commander (mc) Guide: Powerful Text based File Manager for Unix article will give you a quick jumpstart. In this article, let us review how to solve couple of common annoyance about viewing a file in mc.]]> http://www.cyberciti.biz/tips/midnightcommander-set-vi-as-default-editor-viewer.html/feed 9 UNIX Korn Shell Scripting Tutorial / Guidehttp://www.cyberciti.biz/tips/unix-korn-shell-scripting-tutorial.html http://www.cyberciti.biz/tips/unix-korn-shell-scripting-tutorial.html#comments Tue, 09 Sep 2008 12:11:47 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2857 Korn shell scripting is something all UNIX users should learn how to use. This article will teach you to write your own Korn shells scripts.]]> http://www.cyberciti.biz/tips/unix-korn-shell-scripting-tutorial.html/feed 0 How To Configuring Urchin 6 Tracking To Analyze Website Logshttp://www.cyberciti.biz/tips/analyze-website-logs-with-urchin6.html http://www.cyberciti.biz/tips/analyze-website-logs-with-urchin6.html#comments Wed, 20 Aug 2008 18:37:02 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2738 This is 3rd and the final installment for Urchin 6 web analytics software series. Once Urchin is installed, you need to configure tracking on your website. You need to install Urchin sensors - a small piece of javascript tracking code on each of your website's pages.]]> http://www.cyberciti.biz/tips/analyze-website-logs-with-urchin6.html/feed 6 Windows PowerShell vs UNIX BASH Shellhttp://www.cyberciti.biz/tips/windows-powershell-vs-unix-bash-shell.html http://www.cyberciti.biz/tips/windows-powershell-vs-unix-bash-shell.html#comments Wed, 16 Jul 2008 21:10:34 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2472 http://www.cyberciti.biz/tips/windows-powershell-vs-unix-bash-shell.html/feed 1 UNIX Command Line And The History Of The Shellhttp://www.cyberciti.biz/tips/command-line-interface.html http://www.cyberciti.biz/tips/command-line-interface.html#comments Fri, 04 Jul 2008 13:13:25 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2441 http://www.cyberciti.biz/tips/command-line-interface.html/feed 1 How To Avoid Sudden Outburst Of Backup Shell Script / Program Disk I/Ohttp://www.cyberciti.biz/tips/linux-set-io-scheduling-class-priority.html http://www.cyberciti.biz/tips/linux-set-io-scheduling-class-priority.html#comments Tue, 03 Jun 2008 13:13:44 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2339 Describes how to deal with high disk I/O generating scripts or programs using ionice and CFQ scheduling class under Linux.]]> http://www.cyberciti.biz/tips/linux-set-io-scheduling-class-priority.html/feed 11 Goosh.org Unix-like Shell For Googlehttp://www.cyberciti.biz/tips/gooshorg-2.html http://www.cyberciti.biz/tips/gooshorg-2.html#comments Tue, 03 Jun 2008 11:57:59 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2341 http://www.cyberciti.biz/tips/gooshorg-2.html/feed 3 An Interview With Chet Ramey – Maintainer Of Bash Shellhttp://www.cyberciti.biz/tips/when-the-bourne-shell-found-its-identity.html http://www.cyberciti.biz/tips/when-the-bourne-shell-found-its-identity.html#comments Fri, 30 May 2008 12:30:00 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2330 http://www.cyberciti.biz/tips/when-the-bourne-shell-found-its-identity.html/feed 0 How To Become a UNIX command-line Wizardhttp://www.cyberciti.biz/tips/unix-command-line-2.html http://www.cyberciti.biz/tips/unix-command-line-2.html#comments Tue, 27 May 2008 21:55:35 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2325 http://www.cyberciti.biz/tips/unix-command-line-2.html/feed 1 mplayer: Play All Mp3 Files In Reverse Orderhttp://www.cyberciti.biz/tips/reverse-play-mp3-files-in-directory.html http://www.cyberciti.biz/tips/reverse-play-mp3-files-in-directory.html#comments Tue, 06 May 2008 19:23:19 +0000 nixCraft http://www.cyberciti.biz/tips/?p=2269 http://www.cyberciti.biz/tips/reverse-play-mp3-files-in-directory.html/feed 4