Discussion

Linux Users Group: Bash Scripting For Buffoons - NoName Script - @ceri-shaw

Sun, 28 Feb 2016 04:34:54 +0000

NoName Script

⇦ Back to 'Bash Scripting For Buffoons'
This is an attempt to do the same thing as the earlier 'Bills' script utilizing the excellent ' dialog ' program which enables you to present a 'pseudo' GUI within the shell ( using the ncurses library ). You will need to install 'dialog' if you dont already have it and once again it is to be found in the Debian or Ubuntu repositories. This script is not complete but it does display the menu correctly. After that it's mostly downhill. You will need to create a folder called 'vault' in your home folder if you want to try and make this function. Best of luck!
#!/bin/bash
# Script for controlling access to encrypted directory.
#documents

while [ 0 ]; do
pwd > /tmp/pd
PD=" `cat /tmp/pd` "
dialog --title "Enter the Vault" \
--radiolist "Choose one of the following or press to exit" 11 40 6 \
   "1" "Open vault" off\
   "2" "Close vault" off\
   "3" "Append a file" ON 2>/tmp/ans
   if [ $? = 1 ]; then
   rm -f /tmp/ans
   clear
   exit 0
fi
R="`cat /tmp/ans`"
if [ $R = "1" ]; then
chmod 700 ~/vault ;
ccrypt -d ~/vault/* ;
nautilus ~/vault;
elif [ $R = "2" ]; then
chmod 700 ~/vault ;
ccrypt -e ~/vault/* ;
chmod 000 ~/vault ;
elif [ $R = "3" ]; then
dialog --inputbox "Enter the file name:" 8 40 2>/tmp/answer
F="`cat /tmp/answer`"
rm -f /tmp/answer
chmod 700 ~/vault ;
ccrypt -d ~/vault/*
for ea in $F; do mv $ea ~/vault; done
cd ~/vault
for i in $ea; do mv {,"`date`"}$ea ; done
ccrypt -e ~/vault/*
chmod 000 ~/vault ;
cd $PD
fi
rm -f /tmp/pd
done

Linux Users Group: Bash Scripting For Buffoons - Finder Script - @ceri-shaw

Sun, 28 Feb 2016 04:31:11 +0000

Finder Script

⇦ Back to 'Bash Scripting For Buffoons'
OK so this one is just plain dumb! It represents an attempt on my part to develop a basic desktop search script. However it relied upon a host of specific directory locations and worked very badly if at all in the majority of cases. Not recommended!

#!/bin/bash
menu () {
echo "==========================================================="
echo "Please enter search extension in the format *.:-"
read FIND
echo " "
echo "Please enter your search directory using the absolute path:-"
read PLACE
echo " "
echo "If you wish to copy the files to the view directory select 'a'."
echo "If you wish to locate the files select 'b'."
echo "If you wish to locate and copy the files select 'c'."
echo " "
echo "a copy" $FIND "in" $PLACE
echo "b locate" $FIND "in" $PLACE
echo "c locate and copy" $FIND "in" $PLACE
echo " "
read NAME
case "$NAME" in
a) find $PLACE -iname $FIND 2> /dev/null -exec cp -f --target-directory /home/userone/finder/view {} \; ;;
b) find $PLACE -iname $FIND -ls >> /home/userone/finder/location 2> /dev/null ;;
c) find $PLACE -iname $FIND -ls >> /home/userone/finder/location 2> /dev/null ; find $PLACE -iname $FIND 2> /dev/null -exec cp -f --target-directory /home/userone/finder/view {} \; ;;
*) echo "Not a valid option!"
esac
echo " "
echo "Done"
echo " "
}
menu
menu
exit 0

Linux Users Group: Quick Hide Script - Bash Scripting For Buffoons - @ceri-shaw

Sun, 28 Feb 2016 04:27:36 +0000

Quick Hide Script

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This program will whisk a collection of .jpg's from your desktop, tar and encrypt them and hide the encrypted file deep in the hidden folder hierarchy . It will also clear your '.thumbnails/normal' cache and your firefox cache all in one go. I cannot imagine why I wrote this script...it must have been a hypothetical exercise. Unless of course it has something to do with the subject of this post (sadly now defunct). It was all a long time ago. The script makes use of the ' tar ' and ' gpg ' commands. You will, of course, need to tweak it to meet your own requirements. Have fun!

#!/bin/bash
echo "" ;
echo "Enter Foldername" ;
read filename ;
mv *.jpg $filename 2> /dev/null ;
mv *.JPG $filename 2> /dev/null ;
mv *.jpeg $filename 2> /dev/null ;
mv *.JPEG $filename 2> /dev/null ;
tar cf $filename.tar $filename ;
gpg -c -a $filename.tar ;
rm -rf $filename.tar ;
rm -rf $filename ;
mv $filename.tar.asc .$filename.tar.asc ;
mv .*.tar.asc .kde/share/config/Tar2 ;
rm /home/userthree/.thumbnails/normal/*.png 2> /dev/null ;
rm /home/userthree/.mozilla/firefox/lrm26qna.default/Cache/*.png 2> /dev/null ;
echo "" ;
echo "Done" ;
echo "" ;

exit 0

Linux Users Group: Bash Scripting For Buffoons - Bills Script - @ceri-shaw

Sun, 28 Feb 2016 04:20:40 +0000

Bills Script

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If you are in the habit of paying bills online you will no doubt be familiar with the exhortation to print a copy of your payment confirmation for your records. Why? You have a computer. Why would you not screenshot your confirmation and store it on your hard drive rather than piling up bits of paper which you will inevitably lose? Of course any financial records kept on your hard drive need to be stored securely. The following script allows you to do precisely that. It encrypts and datestamps any .png in the folder in which it resides and moves it to the 'bills' folder.
You will need to create a bills folder in 'Documents' and install the ' ccrypt ' program before it will work. You will also need to develop the habit of storing paymentconfirmations as screenshots. Unfortunately the script is not selective and it will consign any and all .png's to the 'bills' folder whether you want them there or not. The menu offers 'Open', "Close', "Append' and "List' options all of which are self-explanatory. This script has a number of amusing quirks and deficiencies as a consequence of under-development.
I suppose it could be useful, it just needs a lot more work.

#!/bin/bash
space () {
echo " "
echo "Done"
echo " "
}
open () {
ccrypt -d ~/Documents/bills/*.cpt ;
nautilus ~/Documents/bills ;
space ;
}
close () {
ccrypt -e ~/Documents/bills/*.png ;
space ;
}
openadd () {
for png in *.png; do mv {,"`date`"}$png; done
mv *.png ~/Documents/bills ;
ccrypt -e ~/Documents/bills/*.png ;
space ;
}
list () {
ls /home/userone/Documents/bills
space ;
}
menu () {
echo "======================================="
echo "Please select from the following menu:-"
echo " "
echo "1 Open bills folder."
echo "2 Close bills folder."
echo "3 Append to bills folder."
echo "4 List bills folder."
echo " "
read NAME
case "$NAME" in
1)
open ;;
2)
close ;;
3)
openadd ;;
4)
list ;;
esac
}
menu

exit 0

Linux Users Group: Bash Scripting For Buffoons - Snapshot Script - @ceri-shaw

Sun, 28 Feb 2016 04:13:55 +0000

Snapshot Script

⇦ Back to 'Bash Scripting For Buffoons'
This script utilises the ' du ', ' ls ' and ' d f ' commands to provide a mass of information about the folder in which it is located. The 'df-h' command also gives you a measure of your current disk usage similar to the following:-
Filesystem Size Used Avail Use% Mounted on
/dev/hda1 46G 31G 108G 23% /
Note that the script is written in such a way that 'ls -lhSR' and 'du -ah/sh' only work with reference to the folder in which they are located. Do not be alarmed when your console shuts down after the script has run. The amazingly useful ' tee ' command has generated a file called 'snapshot' in your current working folder. You will find the output from the command in that file. This script is perhaps a prime candidate for further sophistication and development. At one time I wrote a version that would preserve the current and previous outputs and compare them with the diff command. If you go down that route you can have fun playing with the various output formats that 'diff' provides, for instance, obsessively generating and checking output every two seconds to see if it's somehow different ( which is unlikely ) . I stopped playing with this when I realised that it did nothing that I couldn't accomplish more easily in the GUI. On a 'headless' server though it might still be of some value.
#!/bin/bash
snap ()
{
date
echo " "
echo "Snapshot" ;
echo "---------" ;
echo " " ;
echo "ls -lhSR --authorship /home/userone [Showing permissions , size , authorship and last access times of all files and folders]" ;
echo "----------------------------------------------------" ;
echo " " ;
ls -lhSR --author ;
echo " " ;
echo "du -sh /home/userone [Directory size - Human readable]" ;
echo "----------------------------------------------------" ;
echo " " ;
du -sh ;
echo " " ;
echo "du -ah /home/userone [Showing sub-directory structure and file size inc. hidden files]" ;
echo "----------------------------------------------------" ;
echo " " ;
du -ah ;
echo " " ;
echo "df -h /home/userone [Showing amount of disk space on /home partition]" ;
echo "----------------------------------------------------" ;
echo " "
df -h /home ;
}

snap | tee /home/userone/snapshot

gedit /home/userone/snapshot

exit 0

NOTE: In the likely event that your username is not 'userone' you will need to amend the last two lines accordingly.

Linux Users Group: The Linux Command Line For Beginners Part 2 - @ceri-shaw

Thu, 17 Dec 2015 06:04:12 +0000

Navigation and More

⇦ Part 1 Here

ls, cd, mkdir, touch, cat

gedit

In Part 1 of this series we looked at the wide range of commands available in the Linux Terminal. Now its time to use some of them. Of course we will not be exploring their complete capabilities. For that you will need to consult the relevant 'man' pages but we will be looking at a small subset of commands and exploring basic usage. Let us suppose that we are embarking upon a project that involves the creation of a new sub-directory in the home folder. Let's suppose further that we want to use this folder to store a number of files pertaining to our project that we will need to edit from time to time in a text editor. How would we set this up?
First lets examine the contents of our home directory. To do this simply type 'ls'. The output of the 'ls' command will reveal something like the following on a pristine install of Ubuntu 7.10:-
Desktop Documents Music Pictures Public Templates Videos
Since we are essentially looking for a place to store documents the 'Documents' folder seems like a good place to start. To enter this folder simply type 'cd Documents'. This will take us to the 'Documents' folder where we can once again type 'ls' if we wish to see a list of the contents.
Now we make our sub-directory. We use the 'mkdir' command for this. Simply type 'mkdir project' and a quick 'ls' will reveal that we now have a sub-directory with that name in the 'Documents' folder. Supposing that we need four files to work on, the following commands will create them in the 'project' folder:-
1. cd project
2. touch proj1 proj2 proj3 proj4
If we run the 'ls' command now in the 'project' folder we see that the four files have been created. In order to open 'proj1' for editing, type 'gedit proj1'. The excellent 'gedit' text editor will appear on screen and we can start entering text.
Having entered text we save the file and close 'gedit'. If we wish to read the file in the terminal all we have to do is type 'cat proj1' and the text is displayed.
Of course we have covered a lot of ground in a short time. The above is intended as nothing more than a basic and somewhat superficial introduction to the cd, ls, mkdir, touch and cat commands. A detailed and comprehensive account of their capabilities is to be found in the relevant man pages. It might also be argued that the creation of a sub-directory containing a small number of text files can equally well be accomplished using the graphical file browser. This is true! But some tasks cannot be accomplished so easily, if at all, in the graphical interface and anyone wishing to master the command line should start with the basics.
The 'cd' and 'ls' commands in tandem allow you to explore the full contents of your Linux system. In order to enter the root directory type 'cd /'. Enter 'ls' and you will be presented with a list of all the folders on your drive which will look something like this:-
bin dev initrd lib mnt root sys var
boot etc initrd.img lost+found opt sbin tmp vmlinuz
cdrom home initrd.img.old media proc srv usr vmlinuz.old
From here you can 'cd' into any one of these directories and their sub-directories listing the contents as you go with the 'ls' command. To return to your home folder just typ 'cd ~'. To return to the folder above the one that you are currently in, type 'cd ..'. There are resources in the links section below which will help you understand the Linux Directory Structure. Have fun exploring!
NOTE: In the above example we used a graphical editor - gedit, to create and edit our text files. Some of you may be aware that it is possible to do this in the terminal using the 'vi' editor. Whilst this is perfectly true it is not recommended for beginners. However, for the more adventurous souls amongst you, here is a quick guide to editing with vi:-

1. Open or create a text file - 'vi filename' ( e.g. 'vi proj1' )
2. Vi will open in 'command mode'. All the things you would normally do in a graphical editor by 'pointing and clicking' with a mouse are accomplished in 'command mode' . If you want to enter text or edit the existing contents of a file youmust enter 'insert' mode. To do this simply press the 'i' key on your keyboard.
3. Enter your text.
4. When you have finished editing press the 'Esc' key to re-enter 'command mode'. In order to quit and save, enter the following rather ungainly combination of characters:-
':wq!'
The colon indicates to 'vi' that this is a command. The 'w' and 'q' stand for write and quit. The exclamation mark tells vi to disregard errors.
If all of this appals or unnerves you stick to 'gedit' or 'Leafpad'.

Linux Users Group: The Linux Command Line For Beginners: Part 1 - @ceri-shaw

Thu, 17 Dec 2015 05:48:27 +0000

Opening The Terminal For The First Time

⇦ Part 2 Here

Many people coming to Linux for the first time are wary of the command line. It has a fearsome reputation It is supposed to be difficult and hard to grasp. In fact it is a language which you can learn if you choose to, gradually increasing your vocabulary and mastery of the syntax at whatever pace you find comfortable. Of course you do not need to learn it at all in order to use modern user-friendly Linux distributions like Ubuntu but your experience with Linux will be vastly enriched if you take the time to master the basics.
First things first....lets open the terminal. To do this (on Ubuntu) navigate to Applications--> Accessories--> Terminal. The dreaded black box will open and you will be presented with a prompt. The simplest way to start exploring the massive capabilities of your Linux system is to hit the Tab key twice. You should be presented with something similar to the following:-
Display all 2594 possibilities? (y or n) (see graphic at the top of the page)
Your figure will vary according to the number of installed programs you have on your system but nevertheless if you hit the 'y' key you will be presented with a long list of all the available commands on your machine. Just keep hitting the space bar to scroll through it. When you tire of scrolling through a seemingly endless alphabetic list of meaningless names hit 'Ctrl-C' to return to the prompt.
This is all very well but it would be nice to know what these commands do. This is where the famed 'man' command makes its entrance! Almost all the programs on your system have an accompanying man or manual page. Lets suppose you noticed the 'cd' command in the earlier listing and you wanted to know what it does. You would simply type "man cd" at the prompt. The appropriate manual page will be presented in the terminal. Of course the terminal is not the best place to digest large quantities of text but never fear, almost all the Linux man pages are available online too. Just open your browser and, in this case, search for 'man cd'. Much easier to read! In order to close manual pages in the terminal hit the 'q' key.
Some of the programs on your system will open in the graphical interface and others will run in the terminal. In order to see the difference try typing 'firefox' which will open the Firefox browser and 'ls' which will list files and folders in the current directory in your terminal. Of course you can always open programs in the graphical interface by clicking on the appropriate icon in the Applications menu but command line programs will only run after being invoked in the terminal.
As a rule it is not a good idea to run commands in the terminal unless you have researched them and know exactly what they are going to do. Many commands can only be run as the root or administrative user. We will return to this subject later. (see note below)
So...what practical purpose might what we have learned so far possibly serve? Well let us suppose that you have installed a new program with Add/Remove Programs ( or Synaptic or Apt-get ) and no icon was added to the Applications menu ( this happens frequently ). Let us further suppose that you dont remember the full name of the package but do recall that it started with a 'v'. All you need do is open a terminal , type 'v' and press tab twice to be presented with a list of all the packages on your system whose names begin with 'v'. Having spotted a likely candidate in the list press 'Ctrl-C' to escape and then type the appropriate command. Always assuming you've got the right command your program should appear on the screen ( or in the terminal of course ).

NOTE: The superuser or root account on traditional unix/linux systems is god. It alone has the right to administer all particulars of a given system. Ubuntu is not traditional in this respect, allowing regular users to perform administrative tasks if they preface the commands with the sudo command. If you wish to revert to the traditional arrangement you could do worse than consult this article Rootin' For Root.

Linux Users Group: Quark, Strangeness & Welsh Charm - @ceri-shaw

Thu, 17 Dec 2015 05:43:15 +0000

Anyone who has attempted to make a linked Table of Contents in Scribus will know that the process is about as intuitive as quantum mechanics. Enter Dai!!!!! Not only is the following video 100% accurate in every detail but it is also entirely intelligible??? Looking forward to perusing some more of Dai's 131 videos on 'Show Me Do'

Linux Users Group: Bash Scripting for Buffoons - Eggtimer Script - @ceri-shaw

Wed, 16 Dec 2015 05:02:45 +0000

Eggtimer Script

⇦ Back to 'Bash Scripting For Buffoons'
Yes folks it's an eggtimer, or perhaps more accurately an interval timer. You can tweak it to measure any interval you like but as it stands, it does hard and soft-boiled eggs. It uses the 'case' menu format and a nested 'for' loop to achieve the desired effect. For some reason I decided to call 'menu' as a function. If you want it to beep at the end of the interval you need to have the system 'beep' program installed. For those of you running Ubuntu, it's in the repositories.
#!/bin/bash
# nested for loop
menu () {
echo "======================================="
echo "Please select from the following menu:-"
echo " "
echo "1 Soft boiled."
echo "2 Hard boiled."
echo " "
read NAME
case "$NAME" in
1)
for i in 1 2 3 4
do
echo -n "Min $i: "
for j in 5 10 15 20 25 30 35 40 45 50 55 60
do
sleep 5
echo -n "$j "
done
echo #output newline
done ;;
2)
for i in 1 2 3 4 5 6 7 8 9 10
do
echo -n "Min $i: "
for j in 5 10 15 20 25 30 35 40 45 50 55 60
do
sleep 5
echo -n "$j "
done
echo #output newline
done ;;
*) echo "Not a valid option!" ;;
esac
}
menu
beep
exit 0

An exhilarating screen shot of the Bash Eggtimer in action! Download the script here (.txt) Bash Eggtimer Script

Linux Users Group: Bash Scripting for Buffoons - @ceri-shaw

Wed, 16 Dec 2015 04:11:49 +0000

or How I Learned to Love The Command Line

Firstly let me say that I am a keen supporter of the 'Ubuntification' ( see footnote ) of Linux. I use Ubuntu both on the desktop and on the server and if Linux is ever to conquer the desktop a user-friendly GUI is an essential prerequisite. But recently I have become more irritated by proponents of the GUI versus the command line in computing. The GUI is a place of drudgery, where you go to perform routine tasks with the minimum of thought and concentration. The command line on the other hand is a place of enchantment where you go in order to master a new and powerful tongue which will ultimately allow you to accomplish much, much more . Anyone who dismisses it as an anachronism is either a fool or just plain computer illiterate.
The GUI inhibits creativity by encouraging over-reliance on software ( often proprietary ) which offers only a limited subset of the capabilities of the underlying markup or scripting languages. How often have you heard someone say "Oh I can only do that in Dreamweaver." But, of course, Dreamweaver is nothing more than a brightly colored box with gaudy labels all over it. Webpages are made out of html, css, javascript, flash etc. not GUI buttons. People talk about the irreplacability of productivity software like 'Excel' in which case they might be interested in the following comment from a recent article ( which can be found here )
“you probably don’t see a business user crunching their data in the terminal, do you?”
YES. Our organization use to do all of our monthly reports in Excel. It took nearly two weeks to compile, aggregate, format and print all of them. We now do everything from a BASH script. It’s scheduled as a Cron job that executes during the night when our offices are closed, takes about 15min. to run, and all of the reports are sitting on the printer when we open.

My point is that no matter how creative or productive you are or wish to be you cannot afford to ignore the Bash shell. Once mastered it vastly increases productivity and encourages a whole new way of thinking and self-expression.
Personally, I refuse to learn anything other than by example. My thought processes are far too erratic for logical exposition. But if Bash is a language then it is possible to look upon scripting as an art form. I havent composed any sonnets yet ( mostly limericks so far ) but I live in hope. Ultimately it doesn't matter how much of a disorganised shambles you are, you can still express yourself in Bash.
In conclusion, for the esoteric ones, I have included a link to some scripts of my own below. These scripts are provided for purposes of entertainment and perhaps edification. Beware...this way madness lies!
Footnote :- It seems that my employment of the term 'Ubuntification' occasioned some confusion. However, a public spirited contributor to the Dunedin Linux Users Group in new Zealand offers an interesting definition of the term in this post .

The scripts below are organised into three sub-categories:-
Marginally Useful
Eggtimer Script
Snapshot Script
Of Dubious Usefulness
Bills Script
Quick Hide
Completely Bloody Useless
Finder Script
NoName Script
My purpose in presenting them is twofold. Firstly it is hoped that they will amuse persons who have adequately mastered the art of shell-scripting. The sheer fumbling inelegance of some of the 'solutions' on offer is vaguely reminiscent of Rube Goldberg ( or Heath Robinson ). They are also offered as a resource for the novice shell scripter who may be able to cannibalise pieces of the code and put them to a truly useful purpose. There is a brief guide to making scripts executable on this page and a list of bash scripting resources here .