Web Application Deployment - Shell Programming (bash)

Web Application Deployment module A167

Shell Programming (bash)

Exercises, examples and other material relating to training module A167. This topic is presented on public courses Deploying LAMP - Linux, Apache, MySQL, Perl/PHP, Linux Basics, Deploying Java Applications on Linux / Unix

Articles and tips on this subject		updated
4587	shell - bash. Writing conditional tests and statements - the options available Every language that I teach has conditionals and loops, and the bash shell is no exception. From the three day bash course given last week - an example including lots of alternative tests (but by no means all varlients! for tests in if if command ... ; then The command is run and its ...	2015-11-28
4586	Extending your bash shell with aliases, functions and extra commands Want a command to do some composite job, but it doesn't exist? You can add new commands into your bash script using functions ... see example [here] from last week's course. aliases ... here are the aliases that I'm using to provide my own extra / modified commands on our web server: -bash-4.1$ ...	2015-11-28
4584	Bash ... some new scripts to - handling user input I just completed a three day "bash shell programming" course and have uploaded a whole host of new examples, and updated some older ones too. Here are some examples that relate to inputting from STDIN ... further links to other groups of new examples to follow Asking a question and read from STDIN ...	2015-11-27
4487	Starting MySQL. ERROR! The server quit without updating PID file - how we fixed it. Our MySQL databases are backed up frequently, and I've arranged for our server to email me in the event of a failure. From our /bin/bash script which is run by crontab: /usr/local/mysql/bin/mysqldump -ufgw -psummat -h127.0.0.1 fgw > /home/backups/$HOUR/fgw.sql if [ "$?" -eq ...	2015-05-06
4400	Commenting out an echo killed my bash backup script "Commenting out an echo killed my bash script" - yes, really! Here (with password amended!) is part of my bash script which takes a database snapshot from time to time - and it's been running well over a 24 hour cycle, giving me checkpoints to return to. But it was getting a bit verbose, so I added ...	2015-01-19
3791	The Kernel, Shells and Daemons. Greek Gods in computing The Greek Gods didn't like washing up or ironing. So they employed mortals to to it. Problem was that those mortals didn't last for ever, and sometimes went on strike over one thing and another. So The Gods did a deal with some of the current batch of mortals, and it went like this: "We will make you ...	2012-07-14
1904	Ruby, Perl, Linux, MySQL - some training notes We have just come to the end of a solid 12 days of training ... and we are just getting ready for the next week, with delegates arriving this evening. There's a lot going on behind the scenes, even over this weekend, with the hotel to be prepared as well as the training course. (Picture - our clean ...	2008-11-24 (longest)
1527	Selecting file names in a shell - one word or another If you want to select all file names that include the words "cat" or "dog" in them with file name matching, you can do so using curly braces - that's supported by most modern shells as part of what is known as "globbing". Here's an example - I've just been copying images off my digital camera and I ...	2008-02-02
1468	Lexical v Arithemetic testing, Bash and Perl If you tell a story against someone, best to be telling it against yourself! One of our web servers (running standard, not our own software behind the scenes) has been having a problem with handling denial of service attacks which are coming in from time to time ... and I have a monitoring script running ...	2007-12-12
1345	Perl and Shell coding standards / costs of an IT project There are three major staff costs in the life of an IT project - the specification and development of the system, the maintainance and upgrading of the system though its life, and the investment that's made in data entry and integrity through the life of the system. And although there's a lot of thought ...	2007-09-11
1287	Work and play at Well House Manor - Football and Shell Shortcuts We're running a Linux and LAMP course this week - great group and I'm going to be sorry when it's the end of the course. Yesterday we had a cold buffet lunch for a change, and made the best of the lovely weather and spacious garden to relax for a while - we do a long day, and so a good break at lunch ...	2007-08-01
827	No news is good news with Unix and Linux No news is good news ... so says Linux and Unix. All processes return a status code, and you can expect that to be: 0 - success 1 - failure 2 - abject failure So, for example, the grep utility returns a status as follows: 0 - found what you were looking for! ...	2006-08-10 (short)
749	Cottage industry or production line data handling methods If you're running a cottage industry, for efficiency's sake you'll run the first process on each of your raw components first, and store the partially-completed elements in a basket as they're processed. When you've completed that first process, you'll then apply the second process to each element ...	2006-06-07
63	Almost like old times It felt almost like old times yesterday - now that we're doing a LAMP deployment course (with the "L" standing for Linux if anyone's new to that term), customers have started to ask for the on site Linux element tailored / with a few additions. I found myself writing new material to cover Linux Utilities ...	2006-06-05

Examples from our training material

another	Shell read from stdin up to next new line
askuser	select - choose from stdin
datcopy	Simple copy script to run from command line
dc4	Data copy, loop to copy files one by one, checking
dc5	Data copy, calculating statistics
dc_checked	Data copy with conditional check
dci	Data copy, use of shell variables
dcif	Data copy, use of shell if statement
dcj	Data copy, with command line parameter
eocl	Usage line and for loop - bash
fnk	function definition and use
help	Towards bash scripting - series of commands
lookup.sh	Bourne Again Shell script for CGI Web server
pex	textual manipulation of shell variables
shelc	Shell numric and string comparisons. Also backup script
skcount	Skill counter - sample script in alternative Perl language
skillcounter	Perl script - needs setting up to run as Linux command
wont	Stopping ^C in a shell using trap
yesterday	yesterday in a bash script

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from [here].

Topics covered in this module

What is shell programming?
Running a shell program from the command line
Conditional statements and variables.
Loops.
Shell comparisons and arithmentic.
Functions and other features.
Bourne Again Shell scripts on a web page.
Other Shells.

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