Eli
Navigating to directories
To move to a directory within a directory, type: cd directory (type in the command line)
To move up to the directory containing the one you are in, type: cd ..
To move up two levels, type: cd ../..
You can move as many levels as you like. To move up three levels, type: cd ../../..
To move to a directory in the one up from where you are, type: cd ../directory
To move to the root directory, type: cd /
To move to a directory within the root directory, type: cd /directory
To navigate to the home directory, type: cd ~
To navigate to a directory within the home directory, type: cd ~/directory
Delete directories or files
To delete empty directory, type: rmdir directory
Delete all subdirectories and files inside documents directory, type: $ rm -rf documents/
Where,
-r : Attempt to remove the file hierarchy rooted in each file argument i.e. recursively removes subdirectories and files from the specified directory
-f : Attempt to remove the files without prompting for confirmation, regardless of the file's permissions
In this example, remove data, foo and bar if bar were empty, foo only contained bar and data only contained foo directories:
cd /home/directory
rmdir -p data/foo/bar
Where,
-p - Each directory argument is treated as a pathname of which all components will be removed, if they are empty, starting with the last most component.
Uninstalling software in ubuntu - delete / remove binary packages
Using GUI (Graphical User Interface) Package Management Tool
Click on System > Administration > Synaptic Package Manager and then mark for removal
or to start GUI tool from command line, press Ctrl+Alt+T to evoke terminal and enter: $ synaptic
Here you will start GUI package management tool without Administrative provilleges
To start GUI with administrative privilleges, enter: $ sudo synaptic
Command Line Package Management Tool
apt-get is the command-line tool for handling packages. It is used for adding, removing or updating packages.
To uninstall / delete / remove package, use the following syntax: sudo apt-get remove package-name
For example, to remove package called ffmpeg, enter: $ sudo apt-get remove ffmpeg
To remove package called linpack along with all configuration files, enter: $ sudo apt-get --purge remove linpack
To list all installed package, enter:
dpkg --list
dpkg --list | less
dpkg --list | grep -i 'http'
Concatenating pdf files under ubuntu - Ghostscript
1. Merge two pdf files, file1.pdf and file2.pdf: pdftk file1.pdf file2.pdf cat output mergedfile.pdf
or
2. you can merge files in alphabetical order: pdftk *.pdf cat output merged.pdf
Originally Posted here: http://www.newlinuxuser.com/merge-multi ... -one-file/
This process requires installation of two packages: Ghostscript and pdftk. These packages are available in the repositories of almost all linux-based distributions.
To install them using apt tool, use the following commands:
$ sudo apt-get install gs
$ sudo apt-get install pdftk
To merge two pdf files using gs, open a terminal and copy and paste the following command:
Code: Select all
gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=merged.pdf -dBATCH file1.pdf file2.pdf
Code: Select all
gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=merged.pdf file1.pdf file2.pdfUsing this command, you can merge more than two documents. To merge three or more PDF files, continue to append the file names to the above command, separated by a space.
You can however merge several .eps files into one pdf:
gs -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dSAFER -sOutputFile=single_file.pdf *.eps
Note:
At the first instance I failed to merge two pdf files using the command “pdftk file1.pdf file2.pdf cat output mergedfile.pdf”, the reason is that pdftk could not accommodate the nonstandard pdf files that were somewhat manipulated using xournal. Finally, I found the most powerful command which could take into account the nonstandard docs or ignoring some errors by simply scripting the piece of code: gs -dNOPAUSE -sDEVICE=pdfwrite-sOUTPUTFILE=merged.pdf -dBATCH file1.pdf file2.pdf
where file1.pdf and file2.pdf are input files and merged.pdf is the output
Splitting Large PDF file into many files
Execute the command:
1. pdftk largepdfile.pdf burst
or
2.
Code: Select all
gs -q -sPAPERSIZE=letter -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=output.pdf file1.pdf file2.pdf file3.pdf output.pdfGhostscript is a package which is available by default in Ubuntu that enables you to view or print PostScript and PDF files to other formats, to convert those files to other formats or to combine PDF files. Files don't even need to be PDF files, they can even be PostScript or EPS files, or any mixture of the three.
Here is a brief explanation of the command:
gs starts the Ghostscript program.
-dBATCH once Ghostscript processes the PDF files, it should exit.
If you don't include this option, Ghostscript will keep running.
-dNOPAUSE forces Ghostscript to process each page without pausing for user interaction.
-q stops Ghostscript from displaying messages while it works.
-sDEVICE=pdfwrite
tells Ghostscript to use its built-in PDF writer to process the files.
-sOutputFile=merged.pdf
tells Ghostscript to save the combined PDF file with the specified name.
Compress pdf files
Type:
Code: Select all
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdfinto the Terminal window, replacing "input.pdf" with the name of your PDF file and "setting" with the desired quality level, and then press "Enter."
Quality level settings are "/screen," the lowest resolution and lowest file size, but fine for viewing on a screen;
"/ebook," a mid-point in resolution and file size;
"/printer" and "/prepress," high-quality settings used for printing PDFs.
Converting between formats
To convert between formats, install ImageMagick
convert Desktop.png to Desktop.jpg
You can also specify a compression level for JPEG images. The number must be between 1 and 100. ImageMagick uses the quality level of the input image, if possible. If not, ImageMagick uses the default, 92.
convert Desktop.png -quality 95 Desktop.jpg
Resizing Images
The convert command can also be quickly used to resize an image. The following command asks ImageMagick to resize an image to 198 pixels in width and 155 pixels in height:
convert image.png -resize 198x155 newimage.png
ImageMagick tries to preserve the aspect ratio if you use this command. It will change the image to fit within a 198x155 area, but the image may not be exactly 198x155.
To force the image to become a specific size – even if it messes up the aspect ratio – add an exclamation point to the dimensions:
convert image.png -resize 198x155! newimage.png
You can also specify a specific width or height and ImageMagick will resize the image to that width or height while preserving the aspect ratio. The following command will resize an image to a width of 198:
convert image.png -resize 198 image.png
The following command will resize an image to a height of 155:
convert example.png -resize x155 image.png
Rotation
ImageMagick can be used to quickly rotate an image.
The following command takes an image named Desktop.jpg, rotates it by 90 degrees and saves the rotated image as NewDesktop.jpg:
convert Desktop.jpg -rotate 90 NewDesktop-rotated.jpg
Applying Effects
ImageMagick can apply a variety of effects to an image. For example, the following command applies the “charcoal” effect to an image:
convert image.jpg -charcoal 2 image-charcoal.jpg
The following command applies the “Implode” effect with a strength of 2:
convert image.jpg -implode 2 image-imploded.jpg
More: http://www.howtogeek.com/109369/how-to- ... -terminal/
Other Useful Ubuntu Stuffs
Burning Ubuntu ISO: https://help.ubuntu.com/community/Burni ... o#InUbuntu
Fuse ISO: https://help.ubuntu.com/community/FuseIso
Check MD5SUM and PGP: https://help.ubuntu.com/community/HowToMD5SUM
and
Compare with Ubuntu Hashes: https://help.ubuntu.com/community/UbuntuHashes
Install from USB Stick: https://help.ubuntu.com/community/Insta ... omUSBStick
Run LiveCD by adding Persistent image: https://help.ubuntu.com/community/LiveCD/Persistence
Ubuntu Upgrades: https://help.ubuntu.com/community/Upgrades
and
General Upgrade information: https://help.ubuntu.com/community/UpgradeNotes
Ubuntu Releases: http://releases.ubuntu.com/
Install Skype in Ubuntu 12.04 LTS:
To install Skype, firstly, add the Canonical Partner Repository:
sudo apt-add-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"
and then execute:
sudo apt-get update && sudo apt-get install skype
Install youtube-dl: http://www.tecmint.com/install-youtube- ... load-tool/
Install AIMS Desktop: https://launchpad.net/~aims/+archive/ub ... ms-desktop
Install Radio-Tray - a lightweight dedicated internet radio player for Ubuntu by executing the following:
sudo add-apt-repository ppa:eugenesan/ppa
sudo apt-get update
sudo apt-get install radiotray