catdoc (in C)

The first command line tool we are going to talk about is catdoc. The tool is written in C by V.B. Vagner.

1.1 How to install it:

Download the tool from here.  Go to your downloads directory and untar it. You can use the following commands (in case you are facing problem):

gunzip catdoc-0.94.2.tar.gz tar xvf catdoc-0.94.2.tar

Now we have a catdoc-0.94.2 directory. Go inside this directory and run the following commands to install it:

./configure 
make 
make install

The installation is an easy process and you should not face any problem here.

1.2 How to use it:

There are several option to run the command. I’ll tell the options that works best for the Microsoft Excel conversion:

xls2csv -x "Path_of_Your_XLS_File" -s cp1252 -d 8859-1 > "Path_of_Your_CSV_File"

Note the option “-s” and “-d” (stands for source and destination). These options are used to specify which character encoding is used in the source file and what would be the character encoding for the destination file. Here I have used cpl1252 which is Microsoft character encoding and 8859-1 which is used for Western European character encoding. You can use what other options are available by using the help command.

xls2csv --help

1.3 Pros and Cons:

Pros: Straight forward installation

Cons: No selective conversion in multiple sheet scenario, it coverts all the sheets present in the xls file (one workaround would be to explicitly specify a footer in each sheet and then use option -b in the command), problems with few European characters, problem with date fields (the date fields are messed up big times), messes with quotes.

xls2csv (in Perl)

The second tool we are going to talk about is a Perl script xls2csv written by Ken Prows in Perl.

2.1 How to install it:

Download the script here. Gunzip and tar it like we did in previous section and go the extracted directory and use the following commands to install it:

perl Makefile.PL 
make 
make test 
make install

Remember this Perl script uses a number of other Perl modules:

Locale::Recode Unicode::Map Spreadsheet::ParseExcel Text::CSV_XS

While installing xls2csv, it will give error that the mentioned perl modules have not been installed. It will ask you to download the modules. Download and install these modules when asked. All these module installation requires root privileges. If you do not have root access, then you should follow the instruction given here to install a Perl module.

2.2 How to use it:

The following command can be used to convert Microsoft excel to csv:

xls2csv -x "Path_of_Your_XLS_File" -b cp1252 -w WorkSheetName -c "Path_of_Your_CSV_File" -a 8859-1

Option x and c (means xls and csv) are used to specify the input and output files where as b and a (means before and after) are used to specify the respective character encoding. We have use the same character encoding as in previous tool.

2.3 Pros and cons:

Pros: Good with western European character conversion and date fields, supports selective multiple sheet conversion,

Cons: Several Perl modules need to be installed, first cell should not be empty (otherwise it skips the whole row), messes with quotes

There are couple of other ways as well. Some scripts in Python and Java are also available to use but they are not as good as these two discussed here. I hope the article solves your problem. Question and suggestions are always welcomed. Cheers :)

If you use OpenOffice.org or LibreOffice, then you can save a lot of time by letting a command line utility called JODConverter do the work for you. Don’t let the fact that it’s a command line tool scare you. JODConverter is easy to use and fast. It’s also very effective.

Let’s take a look at how to use it.

Getting Started

Before you go and grab a copy of JODConverter, you’ll need OpenOffice.org or LibreOffice and the Java Runtime Environment for your operating system installed on your computer. Because it’s written in Java, JODConverter runs on Linux, Mac OS, and Windows.

Once you’ve made sure all of that is installed, download a copy of JODConverter. There are two version available: 2.x and 3.0. The main difference between the two version is that version 3.0 supports both LibreOffice and OpenOffice.org. It also seems, from my unscientific observations, to be a bit faster than version 2.x.

Extract the contents of the archive you downloaded to somewhere on your hard drive. For example, if you’re using Linux and downloaded version 3.0 of JODConverter, you can extract the archive to the directory /opt. JODConverter will be installed in /opt/jodconverter-core-3.0-beta-4.

Supported Conversions

JODConverter is very flexible. It can convert between the following formats:

• Word (.doc) to or from Word OpenDocument Text (.odt)
• Excel (.xls) to or from OpenDocument Spreadsheet (.ods)
• PowerPoint (.ppt) to or from OpenDocument Presentation (.odp)

The utility can also handle conversions from RTF and WordPerfect, older OpenOffice.org files, and can even convert all supported formats to PDF.

Doing a Basic Conversion

Now that everything is installed, you’re ready to go. The first thing you need to do is start OpenOffice.org in the background. To do that, open a terminal window and then type the following command:

soffice -headless -accept="socket,host=127.0.0.1,port=8100;urp;" &

Stay in the terminal window and change to the directory containing the files that you want to convert. Then, run the following command:

java -jar [path to JODConverter]/lib/[.jar file] source_file output_file

The path and the name of the .jar file will be different depending on the version of JODConverter that you’re using. If, for example, you’re using version 3.0, here’s a sample path:

java -jar opt/jodconverter-core-3.0-beta-4/lib/jodconverter-core-3.0-beta-4.jar source_file output_file

Let’s say you have a Word file named Secure_Email_Report.doc that you want to convert to OpenDocument format. Just run the following command:

java -jar [path to JODConverter]/lib/[.jar file] Secure_Email_Report.doc Secure_Email_Report.odt

Doing Batch Conversions

Using JODConverter to convert a single file is a waste. You can just as easily do the deed in OpenOffice.org or LibreOffice. But converting large numbers of files is where JODConverter shines. And that’s easy to do.

How? Just run this command:

java -jar [path to JODConverter]/lib/[.jar file] *.input_type -o output_type

In the command above, input_type is the extension of the files that you want to convert and output_type is the extension of the target format. For example:

java -jar [path to JODConverter]/lib/[.jar file] *.doc -o pdf

This converts all Word files (*.doc) in a directory to PDF files. All you need to do is substitute the extensions of the files types that you want to convert from and to.

Scripting the Conversion

Typing that long string at the command line can be a chore. And if you only use JODConverter infrequently, it’s easy to forget the path and name of the .jar file that you need to include in the command.

To get around that problem, you can write a script or a batch file. If you’re running Linux, for example, here’s a good tutorial on shell scripting.

But you don’t even need to do that. If you have Python (a popular scripting language and interpreter) installed on your computer, you can download and use a script named DocumentConverter.py.

To use the script, just type:

python DocumentConverter.py input_file output_file

The script doesn’t seem to work with batch conversion, though.

Final Thoughts

If you’re looking for a fast and efficient way to convert multiple documents to another format, then JODConverter is definitely worth a look. It’s fast, it’s efficient, and it’s flexible. On top of that, it’s fairly easy to use. Even if you only convert documents once in a blue moon, JODConverter is a good addition to your toolkit.

Photo credit: 7rains

Get the app

Just about any Linux distribution with online repositories will have this package available, normally as just mpg123. Ubuntu users can find it in the Software Center or from the command line with

sudo apt-get install mpg123

In the event that your distribution does not have binaries available, you can download the source code here.

The Basics

A single track can be played in a simple and pretty obvious way, just mpg123 followed by the filename, as in:

mpg123 MySong.mp3

Which will play the single track from start to finish with output something like this:

Playlists

You can also use shell wildcards to send mpg123 several files at once. The simplest example is to use the above method, but replace the filename with a quick and easy *.mp3.

mpg123 *.mp3

To set your playlist to shuffle mode, just add a -Z in there

Optionally, you can use normal bash redirect characters to feed mpg123 a list of filenames.

ssh username@my-remote-machine-address
mpg123  -Z  -@  < myplaylistfile

The -@ flag tells mpg123 to treat the following input as a playlist (it’s the shortened form of –list), and the < is a standard bash redirect to pull the text out of the file and use it as mpg123‘s input.

Remote Play Control

This isn’t exactly a “feature” of mpg123, it’s more like a side effect, but for this author, it’s the most handy thing about this application. You see, regular readers or Linux pros probably already know about SSH, the fantastically useful remote shell application with 1001 uses. Since SSH gives you a shell on a remote machine, you can run programs on that remote machine. As mpg123 is just another shell application, the normal rules apply. If you SSH into a machine and run mpg123, it will play out that machine’s speakers.

This is great for me. If I’m sitting on the porch with my netbook on a fine summer day, I can SSH into my desktop (which is hooked up to a home theater) and run a mpg123 to start my music without ever leaving the chair, or being forced to deal with the low-quality underpowered netbook speakers. Just SSH into the machine and run mpg123 as if you were sitting at the keyboard, as in

ssh username@my-remote-machine-address
mpg123  -Z  --@  < myplaylistfile

Conclusion

If you like tag-based music libraries, album art, device synchronization, and other fancy features – mpg123 is clearly not a solution for you. In fact, I doubt there are many people who’d want to use this as their primary music player on a day-to-day basis, but there are certainly times when it comes in handy. We’ve explored just a few of them, and I’m sure our readers can come up with quite a few more. If you’ve found a great use for mpg123, please let us know in the comments.

1. Making a Temporary Filesystem (Ramdisk)

There are several reasons to make a temporary RAM-based filesystem such as fast read/write times or to guarantee that the files will not persist after reboot. Making such a “fake” filesystem is easy, and just requires one command.

mount -t tmpfs tmpfs /mytemppartition -o size=1024m

Where /mytemppartion is the location you wish to mount (it must already exist) and 1024m is the desired size of the ramdisk.

2. Quickly Scheduling Commands

Linux pros almost certainly know the at command, it lets you set a specific time for a job to be run. You simply say what to do and when to do it, and at takes care of the rest. Its usage can be confusing for some, so here’s one common way of scheduling a task with at.

at 12:30 #Enter key
somecommandtorun
anothercommand
#ctrl-D

If you want to verify that it worked, you can easily list the sceduled jobs with

at -l

3. Re-run Previous Commands

Perhaps you ran a long complicated command, but forgot to preface it with sudo, or maybe you didn’t add some necessary options to the end. Instead of retyping the whole thing or going back through your shell history, you can use “double bangs” to represent your last command.

mkdir /etc/myDir
#Permission denied
sudo !!
#Success!

If you’re the type who tracks your command history numbers, you can use the same approach to recall any previous command by referencing its number:

4. Find the PID of a Process

If you need to kill a particular process but don’t have its PID, there’s a simple shortcut to find it – the pgrep command. It doesn’t do anything that can’t be done with a combination of ps and grep, but every little bit helps.

5. Find the Fastest Apt Mirror

Most Debian-derived distributions (but not Ubuntu) have access to a great tool that seems to go largely unnoticed. It’s called apt-spy, and its purpose is to scan the list of known Debian mirrors to find the fastest one for you.

apt-spy update
#This example will scan stable branch of 20 american mirrors for 30 seconds each
apt-spy -d stable -a America -e 20 -t 30

6. Show Listening Ports and their Processes

If you need to see what’s listening for connections on your system, and the processes handling those connections, the old trusty netstat tool is up to the job. Try

netstat -tlnp

to see just such a list.

7. SSH Without Passwords

Many people, such as this author, use SSH on a nearly constant basis. It’s a great tool, there’s no denying that, but having to constantly retype your passwords can get annoying. Instead, you can simply copy your (public) SSH information to the remote machine, allowing it to authenticate you without requiring your password, and all you need is a single command.

ssh-copy-id username@remote-machine

Conclusion

Obviously we’ve only begun to scratch the surface when it comes to useful CLI tools, but the ones listed here are a few of those that we at MTE consider indispensable. If you’ve got any favorite utilities that we forgot to mention, let us know in the comments below.

Of the several command line to do applications out there in the Linux ecosystem, which one should you choose? That’s up to you to decide, but you might want to take a look at iKog. Short for it Keeps on growing, iKog is a Python script that helps you manage your tasks. If you’re into Getting Things Done (GTD for short, a popular method for personal organization), then it’s worth the time to check out iKog.

Installing

First off, make sure that you have Python installed on your computer. If you’re using Linux, then chances are that you do. To check, open a terminal window and type which python. The command should return something like /usr/bin/python. If not, install Python using your package manager or by downloading an installer or source package.

From there, download the script. For convenience, grab the file ikog.py.gz. Once it’s downloaded, open a terminal window and navigate to the directory in which the file was saved. Then, run the following commands:

gzip -d ikog.py.gz
chmod 700 ikog.py
mv ikog.py ikog

The commands extract the script from its archive, make it executable, and rename the script to ikog. The last command isn’t necessary; I just do that to save keystrokes.

From there, move the file to a location in your path, for example, /usr/local/bin.

Using iKog

Whenever you want to work with your task list, open a terminal window and run the command ikog (or ikog.py, if you didn’t rename the script). You’ll see a a program screen and not much else. The first thing that you want to do is add a task. To do that, type add [task] — for example, add Write iKog post for MTE. Then, press Enter.

Remember when I mentioned GTD a few paragraphs ago? Well, GTD has a concept called contexts. A context is a thing, place, or person that you need to complete a task. All contexts have an @ sign in front of them For example, @HomeOffice denotes a task that you need to do in your home office. Contexts also enable you to filter tasks; more on this soon. To include a context when adding a task, type add @Context — for example, add Research neighborhood history @Library.

Adding tasks is one thing, but how do you review them? By typing list, which displays all of your tasks.

If you want to filter by a particular context, just type list @Context — for example, list @HomeOffice.

Notice that in the list, each task has a number. That number comes in handy when you want to complete a task. To do that, type done [task number] — for example, done 1. You’ll be asked to confirm that you want to complete the task. Just type Yes and press Enter.

That’s great, but where is my data stored?

Believe it or not, it’s stored within the iKog script. That makes iKog very portable. If you need to access your to do list across multiple computers that have Python installed on them, you can get a Dropbox account and save the iKog script in a folder in Dropbox. Or save the script to a USB flash drive. Just run iKog from either location.

Of course, storing the data in the script opens you up to problems. What happens if you accidentally delete the script? In iKog, you can enter the command export to save your data in a text file called ikog.tasks.txt. If something happens to the script, you can install a fresh version and then enter the command import ikog.tasks.txt to pull in your data.

iKog is easy to use and is very flexible. It has a number of useful options – this post only took a look at a handful of them. If you want to make your to do list portable, then makes doing that very easy.

Photo credit: xololounge

For a variety of reasons, the Linux command line has a reputation for being difficult and unwieldy. In some cases, that’s true. But a script called ripit turns the command line into an excellent and deceptively simple environment for ripping CDs.

Let’s take a look at how ripit works.

ripit?

ripit isn’t a program. It’s a Perl script that acts as an interface to a number of command line CD utilities including dagrab, cdparanoia, and cdda2wav. The default is cdparanoia.

Instead of having to remember long string of options, ripit walks you through the steps required to rip a CD. You can include a number of command line options if you want or, if you frequently use certain options, save them to a configuration file. More on this later. You can also run ripit with no interaction.

Installation

Obviously, you’ll need to download and install the script. If you don’t have one of the CD utilities mentioned earlier, you can install it using your distro’s package manager. You’ll also need to install a Perl module called CDDB_get, which gets information about each track on the CD from an online database called CDDB.

1. Download ripit-3.9.0.tar.gz to your home folder.

2. Open a terminal and run the commands:

tar xvvfz ripit-3.9.0.tar.gz
cd ripit-3.9.0
sudo make install

Usage

Once ripit is installed, just pop a music CD into your computer’s CD-ROM drive, open a terminal, and type

ripit

You’ll be asked to pick a title from a list. Press 1 on your keyboard and then press Enter. Next, ripit will ask if you want to add or edit information from CDDB. With most CDs, you can just press Enter to skip this step.

If you want to skip those steps, type

ripit --nointeraction

.
In either case, ripit will rip all songs on the CD. Each song will be saved as an MP3 file in your /home directory.

Getting fancy

But what if you don’t want to rip every track on a CD? You can tell ripit to rip only certain tracks or a range of tracks. So, if you want to rip tracks 2, 5, and 9 on a CD, type

ripit 2,5,9

.
Or, if you want to rip tracks 4 to 8, type

ripit 4-8

By default, ripit will save files in a folder in your /home directory with the name of the CD — for example, Various Artists – Putumayo Presents… Turkish Groove. If you’d rather save the files to, say, the folder /home/(yourName)/music, use the command:

ripit --outputdir /home/(yourName)/music

Saving in other formats

So what if MP3s aren’t to your liking? ripit can output files in several other formats, including Ogg, FLAC, MP4, FAAC, and WAV.

Add the option --coder= followed by one of the following numbers to the command line:

• 1 (Ogg)
• 2 (FLAC)
• 3 (FAAC)
• 4 (MP4)
• 6 (WAV)

For example:

ripit --coder=1 #rip in Ogg format

Using a configuration file

Nobody wants to remember a bunch of command line options. Especially if you don’t use ripit all that often. You can get around that by specifying the options that you need along with the --config option. ripit will save a configuration file, called config, to the folder .ripit in your /home directory.

You only have to do this once. Whenever you run ripit, the script reads the configuration file.

Is that all?

Definitely not. This post only scratches the surface of ripit’s capabilities. Just type ripit --help to get a full list of options. Then, choose the ones that you use most and save them to a configuration file.

If you’re a command line junkie who rips a lot (or even a little) music, then you’ll find ripit to be an indispensable tool. It’s easy to use and gets the job done quickly and efficiently.

Photo credit: grz3gorz

There are several advantages to using th command line instead of the visual interface:

• We can check on individual item, and isolate those that are causing the problems.
• Command line tend to have more options so we can test the system deeply.
• We can use scripts to automate the process.

In this article, we will show you how to diagnose and fix network problems using the command line.

To get started, first make sure that you are running the command prompt with Administrator privilege.

How to know if your cable is connected

You can use the ipconfig tool to check if you are experiencing some problem with your cable. Windows will show up a list of the interfaces and if they are connected or not.

How to know if your gateway is working

A gateway is the device, usually a router, that connects your computer to other networks and Internet. If you cannot connect with your device, it is pretty sure you are not going to connect to the Internet. First you need to know the IP address of the device. You can use Ipconfig to give us the information about the default gateway:

Now you can use ping to test if the gateway respond. This tool informs if a device with a given IP is answering. In plain English, with this test, we know that our network adapter, the cable and the router are connected correctly.

How to know if your dns is working

A DNS server is capable of converting a site name, for example www.maketecheasier.com, to its IP address. To connect to a computer in Internet, Windows needs that number. If you cannot connect to your DNS , it is almost impossible that Internet works.

As you can see in this case I have the same router and DNS IP address.

To test the DNS you can use nslookup. This command make a query to that server. In the following image you can see how the server resolve Make Tech Easier address.

How to know if a process is opening too much connections

Every time a program needs to connect to Internet or other machine, it opens a new connection. A router can only handle a limited number of connection. If for any reason, a program opens many connections, you can end up with a block Internet.

We can do this with the command netstat and the parameters “a” and “b”

netstat -a -b

You can see what programs are using these connections. In this case, you can see that I have a program named “Filezilla Server” listening in port 21.

How to check firewall rules

Firewall misconfiguration can lead to Internet malfunctioning. A firewall configuration is no more than a set of rules deciding whether an application can access the Internet or not. By default, these rules appear in abundance and you cannot see all of them in one screen. Instead, we can insert this information on a text file using the following commands:

netsh advfirewall firewall show rule name=all > firewallrules.txt

notepad firewallrules.txt

The first command access the firewall configuration and write it to a text file. The second command open the text file in a new notepad window.

A basic use of the netsh utility can inform us if there is one or more blocking rules to that use the command:

netsh advfirewall firewall show rule name | find "Block"

Unfortunately it doesn’t show what is the program blocked by that rule.

What other tricks do you use to test your internet connections?

After installing the extension, the first thing to do is to press “g” to bring up the gleebox. This will be the main control center. There are several options you can do with the gleebox. You can type any phrase(s) and it will search the current page for links that match your query. You can then scroll through the links to find what you want. If no matching query is found, when you press Enter, it will perform a search with your phrase(s) or bring you to the page if the phrase is an URL.

You can also use the “?” prefix to perform a series of actions. For example, typing “?h” will highlight the H1, H2 and H3 headings and “?img” will highlight linked images. Available options include

• ?h: Select main (h1, h2 & h3) headings
• ?img: Select linked images
• ??: Select text input fields. Hit ENTER to give focus to the selected field.
• ?a: Select all links

More useful features

The best part about gleeBox is the ability to use the “!” prefix to access to plenty of external services. For example, at any page, you can press “g” to bring up the gleeBox and type “!read“. This will transform the existing page to reading mode.

A list of useful commands include:

• !read: Transform the page for a better reading experience using the Readability project
• !shorten: Shorten the URL of the current page using bit.ly
• !tweet: Redirect to twitter.com with the URL of the current page in the text field
• !rss: Open the current page’s RSS feed in Google Reader
• !snap: Take a screenshot of the current page in Chrome
• !share: Share the current page.
• and many more…

Running YubNub or a Quix command

Both YubNub and Quix are web tools that allow you to enter a command line and perform an action. These tools are built into gleeBox so you can work with command lines too. The command comes with a “:” prefix and a dollar sign ($) represents the current URL. Available commands include “:fbshare $” – Share the current page on Facebook, “:wp cricket” – Search Wikipedia for cricket etc. With Quix, you can even create your own command and use it in gleeBox.

Wrapping up

The above mentioned features are not conclusive of what gleeBox is capable of doing. There are more things such as jQuery commands, ESP mode that I did not mention. Will gleeBox replace the mouse completely? No, it won’t. But its usefulness and versatility can indeed speed things up and make you more productive. Try it out and you will know. Don’t forget to check out the user manual too.

gleeBox | gleeBox for Google Chrome | gleeBox for Firefox | gleeBox for Safari

The Basics

As noted above, wget is most commonly used to quickly grab a file from somewhere on the web.

wget http://mydomain.com/file.zip

Which would simply grab the file and save it to the current directory.

If you want to save to a different filename or different location, you use the -O flag.

#Remember it’s a capital "O" not zero or small "o"

wget http://download.maketecheasier.com/Firefox_shortcut_keys.pdf -O Documents/ffkeys.pdf

You may be downloading multiple files, in which case you may want to specify a location for all downloads. Just use the -P flag (or –directory-prefix=LOCATION) to specify where they go.

As you can see, that’s a lot of output. Let’s try the -q option to clean it up, making it more suitable for scripts.

wget -q http://mydomain.com/file.zip

Similarly, you can use the -nv option for just a little output, but not as much as the default.

Fancy stuff

What if your download failed, and you want to resume? What if the file already exists, and you don’t want to overwrite it? There are options to handle those as well as several other situations.

To resume a broken download, you’d use the -c flag (or –continue)

If you need to make sure your command (or script) doesn’t overwrite any existing files, use the -nc option (for no-clobber)

There are times when you can’t be certain if filenames will be case-sensitive on both ends, but the –ignore-case flag will negate that problem.

To limit the download rate, use the –limit-rate=RATE option, as demonstrated below.

wget –limit-rate=20000 http://ftp.us.debian.org/debian-cd/5.0.7/amd64/iso-cd/debian-507-amd64-netinst.iso

FTP Options

As noted earlier, wget supports FTP as well. If you just specify a FTP site, like

wget ftp://ftp.us.debian.org/debian-cd/5.0.7/amd64/iso-cd/debian-507-amd64-netinst.iso

wget will assume you want an anonymous login. If that’s not the case, you can manually specify things like username and password with the following flags:

• –ftp-user=USER Specifies the username for login
• –ftp-password=PASS Specifies password
• –no-passive-ftp Disables passive transfer mode.

As well as a few others for advanced use cases.

Timeouts, Retries, and Failed Downloads

Finally, wget comes with several options relating to server connection problems and timeouts. Not all failures can be dealt with of course, but the following flags are all intended to help deal with server issues:

• –tries=NUMBER Specify number of times to retry download
• –retry-connrefused Retry download even if connection is refused by server.
• –continue Resumes an incomplete download, used as -c above
• –timeout=SECONDS Global setting – how long to wait before timeouts
• –wait=SECONDS How long to wait between successful downloads (if repeating)

Conclusion

For such a simple, basic, built-in utility, wget has a surprising amount to offer. Next time you find yourself writing an internet-aware shell script, or needing to get that missing driver file on your broken computer, give wget a shot. If you’ve got any interesting stories about how wget has got you out of a jam, let us know in the comments below.

Regardless which camp you belong, as long as you are using Linux (doesn’t matter which distro), you are sure to hit the terminal and type some commands into it at some point of time. Why not embrace it and take the opportunity to learn something new?

Here are some websites, tools and tricks that you can make use of to learn Linux command line. This is in no way a comprehensive list, but will be a good start for those who wish to get started.

Note: The “command line” stated here can refer to the bash commands you type in the terminal, or writing your own bash scripts.

Website

1. Linux Command.org

LinuxCommand.org is a site on… you guess it, Linux command. If you know absolutely nothing about the command line, this is a good starting ground. LinuxCommand is more like a school, where it teaches you from the basic, such as “what is a shell?” to simple command usage and lastly, advanced techniques like “how to write your own shell scripts“.

http://linuxcommand.org

2. CommandLineFu

There are often cases when you want to get things done on the terminal, but can’t remember the exact code. When such cases occur, a good place to check out is CommandLineFu. Just think of a social network for command line and you get CommandLineFu. CommandlineFu is the place where people share the commonly used bash code so you just have to copy/paste the code to the terminal instead of writing your own. It is also a great way to discover the infinite possibilities that you can do on the terminal.

CommandlineFu

3. ShellFu

Similar to CommandlineFu, ShellFu is also a place where you can find plenty of codes, examples and uses of the command line. What makes it different is that ShellFu is more like a blog (rather than a social network), is moderated and there is no vote up/down feature.

ShellFu

4. O’Reilly Linux Command and SS64

O’Reilly Linux Command and SS64 bash are both a good place to go if you need just a quick reference of a particular command. All the commands are sorted in alphabetical order, so you can easily find the commands you want.

O’Reilly Linux Command
SS64

Tools

5. CLI Companion

CLI Companion is a replacement for your default terminal. It is divided into two panes. The upper pane is a library of the commonly used bash command and the lower pane is the actual terminal. You can scroll through the library to find the command you want, right click on it and select “Apply”. The command will get executed in the terminal below.

In Ubuntu, you can install via the command:

sudo add-apt-repository ppa:clicompanion-devs/clicompanion-nightlies

sudo apt-get update

sudo apt-get install clicompanion

6. Ebook – Bash Guide For Beginners

For beginners who like to learn bash command on the move, a good way is to download the free ebook – Bash Guide For Beginners and read it on your mobile devices. The ebook contains (almost) every single things you need to know about bash command. Even if you are experience with bash command, it never hurts to have a ebook by your side where you can refer from time to time.

Bash Guide For Beginners

Tricks

Here are some tricks that you can use to increase your productivity.

7. Bash Autocompletion

One easy way to get around bash is to use the autocompletion feature. When you are halfway through typing a command, you just have to press the “Tab” button on your keyboard and it will autocomplete your command for you. If it can’t understand your command, it will show a list of options for you to choose.

8. Creating alias

If you frequently use the same command over and over again, it is a good idea to add an alias for that command. An alias is just a short for a (long) command. You can use aliases for a variety of reasons, such as shortening a long command or making the Linux shell act more like a Windows/Mac/Solaris/BSD/Whatever shell.

Creating bash alias

9. Mastering the bash history

The bash history contains the list of the commands that you have used before. To access your bash history, the simplest way is to use the Up/Down arrow key in the terminal. More bash history tricks can be found at the link below.

Mastering bash history

10. Using of bash prompt

Bash prompt is the result that appears when you enter a bash command. Most people are using the default system setting (gray color), not knowing that they can change the prompt settings and get it to display additional information and colors.

bash prompt

As I said above, this is by no means the most comprehensive list around and I am sure there are plenty of other useful websites, tools and tricks that I have left out. Do tell us about it in the comments.

To add events/appointment to your Google Calendar, the most primitive way is to open your web browser, login to the Google Calendar site and add an event. What about the geekiest (and fastest) way? By the command line, of course.

Gcalcli is a Python application that allows you to access and manage your Google Calendar from a command line. You can use it to retrieve your agenda, event list, and quickly add new events. What’s more, it can also be used as a reminder service to help you remember the things that you need to do.

Installation

Gcalcli is included in the Ubuntu repository, which means you can easily install via the Ubuntu Software Center, Synaptic Package Manager, or simply with the command line:

sudo apt-get install gcalcli

Configuration

Before we start, we need to create the configuration file. Open a text editor. Paste the following lines:

[gcalcli]
user: yourusername
pw: yourpassword

Replace “yourusername” with your Google account login name, without the gmail.com.

Replace “yourpassword” with your Google login password.

Save the file in your home folder with the filename .gcalclirc (don’t forget the “.” in front of the galclirc and no file extension is required)

Usage

To test it, open a terminal and type

gcalcli agenda

It should show your agenda for the next 5 days.

To get a quick glance of your next 2 weeks agenda

gcalcli calw 2

Whole month agenda

gcalcli calm

You can also set gcalcli to show a reminder popup if the event is within 10 minutes from the current time.

gcalcli remind 10

One thing though, there is no automation for the reminder service, so you need to run the command everytime to remind you of your event. A good way to automate it is via crontab or using gnome-schedule

To add an event to Google calendar, use the command

gcalcli quick <event>

Replace the <event> with a brief description of the time, date and event detail. For example:

gcalcli quick '5pm 31/7/2010 Meeting with Advertisers'
# or
gcalcli quick 'Dinner with Eric 7pm tomorrow'

Display Google Calendar on your desktop

To get Google Calendar onto your desktop, we are going to use a combination of gcalcli and conky.

Install conky:

sudo apt-get install conky

Open a text editor and paste the following text:

alignment top_right
background no
border_width 0
cpu_avg_samples 2
default_color white
default_outline_color white
default_shade_color white
draw_borders no
draw_graph_borders yes
draw_outline no
draw_shades no
use_xft yes
xftfont DejaVu Sans Mono:size=12
gap_x 5
gap_y 60
minimum_size 5 5
net_avg_samples 2
double_buffer yes
out_to_console no
out_to_stderr no
extra_newline no
own_window yes
own_window_class Conky
own_window_type override
own_window_transparent yes
own_window_hints undecorated,below,sticky,skip_taskbar,skip_pager
stippled_borders 0
update_interval 1.0
uppercase no
use_spacer none
show_graph_scale no
show_graph_range no
text_buffer_size 8096
 
TEXT
${execi 300 gcalcli --nc --cals=owner calw 4}

Save the file in your Home directory with the filename .conkyrc

Press Alt + F2. Type in “conky” and press Enter.

Your agenda for the next 4 weeks will now appear on your desktop and it will refresh every 5 minutes.

Need more help on gcalcli? Check out their HowTo wiki.

Try it out and let us know if it works for you.

For those just starting out with Linux, or the command line specifically, the program that displays the command prompt and handles your commands is called bash, or the Bourne Again Shell. In this article we’ll be using the words command line and shell interchangeably to refer to interacting with Linux through bash.

Today we’ll be covering:

• Changing the shell startup routine
• Making a more useful command prompt
• Creating aliases for long or complex commands

.bashrc and .bash_profile

These two files are often the source of some confusion. At first appearance, they seem to do the exact same thing – running startup instructions every time you open a command prompt. In short, .bash_profile runs when you start a shell from a login screen (such as a console system login) and .bashrc runs for non-login shells (such as running Terminal from your system menu). The .bashrc file is the one you’ll be using the majority of the time so that’s the one we’ll use in our examples today.

As I said, .bashrc is loaded by bash whenever you open a new shell. Chances are you already have a .bashrc file that was created for you when you first installed your Linux system. To see what’s already in there, load up your preferred text editor and open

/home/YourUserName/.bashrc

(By default, the file is hidden from public view. You’ll have to right-click and select Show Hidden Files before it can show itself.)

You’ll probably see several lines of code, bash shell scripting to be precise, already in there. The default .bashrc in most distros has some code to do things like color prompts (which we’ll get into a little bit) and some handy aliases (which we’ll get into a lot).

Feel free to glance through the current contents of the file so you have an idea what’s already happening on each new shell session, but for the sake of this article we can safely ignore the current settings and just add what we want to the end.

Instead of putting our new items directly into the .bashrc file, we’re going to take a slightly different approach.  Each user on the system has their own .bashrc file in their home directory. If we wanted to make changes to the way bash runs, we’d have to place our changes in each of those files. If you later decide that what you did wasn’t quite what you wanted, you’d have to go through all of those files again and make your updates. Instead of all that hassle, we’re going to make a single file with all our custom settings, and just tell .bashrc to load from that file.  The diagram below demonstrates:

By placing the source command at the end of the .bashrc file, it will pull our commands in from the custom-shell.sh file and overwrite the default prompt and default aliases with the ones we’ve specified. This way, we can make a single file (/etc/custom-shell.sh or whatever else you’d like to name it) and just tell each user’s .bashrc file to load it. So if you’ve still got your .bashrc file loaded in your text editor, move all the way down to the bottom and add

source /etc/custom-shell.sh

Note – you can take this a step further and add the source line to the .bashrc file in /etc/skel. That way, all new users created on the system will already have our source line included!

Save the .bashrc file and then create a new, blank text file named custom-shell.sh.  This is where we’ll be putting all of the new settings in the following sections.

The Prompt

Every system has a default prompt. Usually, it’s a bland, default prompt with only a little bit of useful information.  It probably looks something like:

josh@roberts:~$

To test out exactly how prompt customisation is done, enter the following into the shell:

export PS1="Custom > "

This will turn your prompt into a simple arrow. No useful info of any kind, but it shows the basic idea of how you change the contents of your prompt.

Over the years, people have taken prompt customisation to the extreme, putting all kinds of info into it. I won’t go into a huge amount of detail on how to handle colors and multi-line prompts and adding live info, but I will give a nice looking, useful prompt that you could use as a base for your own. In the custom-shell.sh file we created earlier, paste in:

export PS1="\n\[\033[1;36m\]\u\[\033[1;37m\] \[\033[0;36m\]`date`\n\[\033[0m\][\[\033[1;33m\]\w\[\033[0m\]] "

Most of what you see there are color codes telling bash to switch back and forth between various colors for the text in the prompt. The end result of all this gibberish is a rather nice looking and easy to understand prompt.

Save the custom-shell.sh file after pasting in the code above. If you save it in /etc, you’ll probably need root privileges. You can save it anywhere you want, but make sure you point your .bashrc to the right place. To test out your new prompt, you can either close and re-open your shell, or just type

source .bashrc

into your current shell.

Your .bashrc file should read our new prompt info from the custom-shell.sh file and make your prompt nice and fancy with colors and all.

For an EXTREMELY detailed guide on prompt magic, see the Official Linux Prompt HOWTO.

Aliases

I might as well tell you up front – I love aliases. The first thing I do when I install a new system is set up my preferred aliases. As the name implies, an alias is just another name for a command. For example, my most used alias is one I call “gimme” which bash translates to “sudo apt-get install”. You can use aliases for a variety of reasons, such as shortening a long command or making the Linux shell act more like a Windows/Mac/Solaris/BSD/Whatever shell. I suggest pasting the following aliases into your custom-shell.sh file. Those who use distros other than Debian/Ubuntu style can translate the apt-get aliases into the appropriate yum command, or whatever package utility you prefer, and of course the same is true for aptitude and portage users.

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#
#Apt-related aliases
#
alias gimme="sudo apt-get install"            #Install new software
alias acs="apt-cache search"                    #Search available packages
alias purge="apt-get --purge remove"        #Removes package and its config files
alias update="sudo apt-get update"
alias debclean="sudo apt-get clean && sudo apt-get autoremove"  #Removes some unneeded files
#
#Misc useful aliases
#
alias ls="ls --color=auto"                           #Plain ls with color
alias ll="ls -l --color=auto"                         #Detailed list with color
alias config="dpkg-reconfigure"                #Re-run the configuration step for a package
alias cmi="./configure && make && sudo make install"    #Common steps to install package from source
alias numfiles="echo $(ls -1 | wc -l)"          #Count the number of files in current directory
alias dfree="df -h"                                       #See how much hard drive space is free in easy-to-read format
alias favdir="cd /directory/you/use/a/lot"   #Quickly switch to a directory you often need (music, documents, etc)

Add whatever else you think might be useful, or change the ones I’ve suggested to suit your needs. Instead of gimme and acs, you could use get and got. Some people transitioning from Windows like to make aliases to mimic Windows commands: copy to replace cp, move to replace mv, ipconfig to replace ifconfig, etc.

Your custom-shell.sh should now look something like this:

Once the custom-shell.sh file is saved, and .bashrc is set to point to it, re-open your command prompt and you should have a nice looking, useful prompt with several handy aliases to make things a little easier.

I would love to hear about you favorite aliases! Leave a comment and share some useful command shortcuts you’ve found, or maybe a nice prompt. The command line can be a very powerful tool, and I’d love to know ways you’ve found to make it even better.