Linux Shortcuts and Tricks
The Linux command line offers a much easier, and cross-distribution, method of completing common tasks. Certain commands and syntaxes may be cumbersome to memorize, there are several helpful command line tips and cool tricks to make your work in the terminal much easier. They’ll definitely get you more productive than before and make you enjoy using the terminal. Here are a few tricks and shortcuts that will save you a lot of time while working with Linux command line.
Todays, I’ll show you some pro Linux command tricks that will save yours a lot of time.
-
Switch back to the last working directory:
Suppose you end up in a long directory path and then you move to another directory in a totally different path. And then you realize that you have to go back to the previous directory you were in. In this case, all you need to do is to type this command:
cd -
This will put you back in the last working directory. You don’t need to type the long directory path or copy paste it anymore.
2. Go back to home directory
This is way too obvious. You can use the command below to move to your home directory from anywhere in Linux command-line:
cd ~
However, you can also use just cd to go back to home directory:
cd
Most modern Linux distributions have the shell pre-configured for this command. Saves you at least two keystrokes here.
3. List the contents of a directory
You must be guessing what’s the trick in the command for listing the contents of a directory. Everyone knows to use the ls -l for this purpose.
And that’s the thing. Most people use ls -l to list the contents of the directory, whereas the same can be done with the following command:
ll
Again, this depends on the Linux distributions and shell configuration, but chances are that you’ll be able to use it in most Linux distributions.
4. Running multiple commands in one single command
Suppose, you have to run several commands one after another. Do you wait for the first command to finish running and then execute the next one? You can use the ‘;’ separator for this purpose. This way, you can run a number of commands in one line. No need to wait for the previous commands to finish their business.
command_1; command_2; command_3
5. Running multiple commands in one single command only if the previous command was successful
In the previous command, you saw how to run several commands in one single command to save time. But what if you have to make sure that commands don’t fail?
You can use && separator for this case. && makes sure that the next command will only run when the previous command was successful.
command_1 && command_2
A good example of this command is when you use sudo apt update && sudo apt upgrade to upgrade your system.
6. Easily search and use the commands that you had used in the past
Imagine a situation where you used a long command couple of minutes/hours ago and you have to use it again. Problem is that you cannot remember the exact command anymore.
Reverse search is your savior here. You can search for the command in the history using a search term.
Just use the keys ctrl+r to initiate reverse search and type some part of the command. It will look up into the history and will show you the commands that matches the search term.
ctrl+r search_term
By default, it will show just one result. To see more results matching your search term, you will have to use ctrl+r again and again. To quit reverse search, just use Ctrl+C.
Note that in some Bash shells, you can also use Page Up and Down key with your search term and it will autocomplete the command.
7. Unfreeze your Linux terminal from accidental Ctrl+S
You probably are habitual of using Ctrl+S for saving. But if you use that in Linux terminal, you’ll have a frozen terminal.
Don’t worry, you don’t have to close the terminal, not anymore. Just use Ctrl+Q and you can use the terminal again.
ctrl+Q
8. Move to beginning or end of line
Suppose you are typing a long command and midway you realize that you had to change something at the beginning. You would use several left arrow keystrokes to move to the start of the line. And similarly for going to the end of the line.
You can use Home and End keys here of course but alternatively, you can use Ctrl+A to go to the beginning of the line and Ctrl+E to go to the end.
9. Reading a log file in real time
In situations where you need to analyze the logs while the application is running, you can use the tail command with -f option.
tail -f path_to_Log
You can also use the regular grep options to display only those lines that are meaningful to you:
tail -f path_to_log | grep search_term
You can also use the option F here. This will keep the tail running even if the log file is deleted. So if the log file is created again, tail will continue logging.
10. Reading compressed logs without extracting
Server logs are usually gzip compressed to save disk space. It creates an issue for the developer or sysadmin analyzing the logs. You might have to scp it to your local and then extract it to access the files because, at times, you don’t have write permission to extract the logs.
Thankfully, z commands save you in such situations. z commands provide alternatives of the regular commands that you use to deal with log files such as less, cat, grep etc.
So you get zless, zcat, zgrep etc and you don’t even have to explicitly extract the compressed files. Please refer to my earlier article about using z commands to real compressed logs in detail.
This was one of the secret finds that won me a coffee from my colleague.
11. Use less to read files
To see the contents of a file, cat is not the best option especially if it is a big file. cat command will display the entire file on your screen.
You can use Vi, Vim or other terminal based text editors but if you just want to read a file, less command is a far better choice.
less path_to_file
You can search for terms inside less, move by page, display with line numbers etc.
Using the argument of the previous command comes handy in many situations.
Say you have to create a directory and then go into the newly created directory. There you can use the !$ options.
12. Using alias to fix typos
You probably already know what is an alias command in Linux. What you can do is, to use them to fix typos.
For example, you might often mistype grep as gerp. If you put an alias in your bashrc in this fashion:
alias gerp=grep
This way you won’t have to retype the command again.
13. Copy Paste in Linux terminal
This one is slightly ambiguous because it depends on Linux distributions and terminal applications. But in general, you should be able to copy paste commands with these shortcuts:
- Select the text for copying and right click for paste (works in Putty and other Windows SSH clients)
- Select the text for copying and middle click (scroll button on the mouse) for paste
- Ctrl+Shift+C for copy and Ctrl+Shift+V for paste
14. Kill a running command/process
This one is perhaps way too obvious. If there is a command running in the foreground and you want to exit it, you can press Ctrl+C to stop that running command.
15. Run your program after session killing
When you run any program in the background and close your shell, definitely it will be killed, what about if it continues running after closing the shell.
This can be done using the nohup command, which stands for no hangup.
nohup wget site.com/file.zip
This command is one of the most useful Linux command line tricks for most webmasters.
A file will be generated in the same directory with the name nohup.out contains the output of the running program.
16. Using yes command for commands or scripts that need interactive response
If there are some commands or scripts that need user interaction and you know that you have to enter Y each time it requires an input, you can use Yes command.
Just use it in the below fashion:
yes | command_or_script
17. Empty a file without deleting it
If you just want to empty the contents of a text file without deleting the file itself, you can use a command similar to this:
> filename
18. Find if there are files containing a particular text
There are multiple ways to search and find in Linux command line. But in the case when you just want to see if there are files that contain a particular text, you can use this command:
grep -Pri Search_Term path_to_directory
I highly advise mastering find command though.
19. Using help with any command
I’ll conclude this article with one more obvious and yet very important ‘trick’, using help with a command or a command line tool.
Almost all command and command line tool come with a help page that shows how to use the command. Often using help will tell you the basic usage of the tool/command.
Just use it in this fashion:
command_tool --help
20. Count number of files within a directory in Linux (not using wc)
ls -l . | egrep -c ‘^-’
21. Take top n files in a folder/directory and then next m files into a new directory
ls dir1 | head -n 10 | xargs -I X cp dir1/X dir2 ls dir1 |tail -n +11 | head -n 5 | xargs -I X cp dir1/X dir2
22. Move files from one location to another
mv -v ~/dir1/* ~/dir2/
23. Move a random shuffled sample subset of files to another location
shuf -zen200 source/* | xargs -0 mv -t dest
24. Save files list to a text file
ls > filenames.txt
25. Find specific files based on filenames list and move them
xargs -a file_list.txt mv -t /path/to/dest
26. Find files common to two directories
comm -12 <(ls dir1) <(ls dir2)
The output will be differentiated by 0, 1, or 2 leading tabs as:
files only in dir1
files only in dir2
files in both dirs
27. Using Screen
screen -S <any name> # To create a screen screen -ls # To see a list of the ones you created screen -d -r <name of a detached screen> # To restore detached screen -X -S [session # you want to kill] quit # To kill a screen
28. Finding the biggest files
ls -lSrh ls -lSrh *.<file format extension like txt or mp3>
29. Look for the largest directories
du -kx | egrep -v "\./.+/" | sort -n
30. man page descriptions for a particular keyword
man -k <insert keyword> # use / and search for a term by typing it
31. Listing today’s files only
ls -al --time-style=+%D | grep `date +%D`
32. Merging columns in files
#!/bin/sh
length=`wc -l $1 | awk '{print $1}'`
count=1
[ -f $3 ] && echo "Optionally removing $3" && rm -i $3
while [ "$count" -le "$length" ] ; do
a=`head -$count $1 | tail -1`
b=`head -$count $2 | tail -1`
echo "$a $b" >> $3
count=`expr $count + 1`
done
chmod u+x merge.sh # to make the file executable
/path/to/merge.sh file1 file2 file3
33. Find and execute
find . -name '*.gz' # locate all the gzip archives in the pwd find . -name '*.gz' | xargs gunzip -vt
34. Rename and resize images
#!/bin/sh
counter=1
root=mypict
resolution=400x300
for i in `ls -1 $1/*.jpg`; do
echo "Now working on $i"
convert -resize $resolution $i ${root}_${counter}.jpg
counter=`expr $counter + 1`
done
chmod u+x picturename.sh # to make it executable
picturename.sh /path/to/pictdir
35. htop
Once htop is installed, you can run it by typing htop on the command line. When you do, you’ll get a full overview of all the processes running on your system along with details like process IDs, CPU and RAM usage, and how long they’ve been running.
36. ranger
Once installed, type ranger in the command line and your terminal will transform into an interface that makes it easy to navigate your entire filesystem using just a keyboard (though you can use your mouse too, if you want).
37. tmux
To split screens either vertically or horizontally
Ctrl+B and then Shift + 5 # Vertical split Ctrl+B and then Shift + " # Horizontal split Ctrl+B and then direction keys # To navigate screens Ctrl+B and then X # To kill Ctrl+B and then [ # To get scroll mode, hit q to exit
38. Apropos
apropos <keyword>
This will match the “keyword” string with said command’s help string and display a list of such commands
39. Transferring files without ftp or scp
# Run on destination server
nc -l -p 1234 | uncompress -c | tar xvfp - # Run on sending server tar cfp - /some/dir | compress -c | nc -w 3 [destination] 1234
40. Create Aliases for SSH logins
vim ~/.bash_aliasesType your list of aliases in the format │alias <name>='ssh user@hostaddress'source ~/.bash_aliases
# If you get a Bad owner or permissions on /Users/username/.ssh/config error, then type
chmod 600 ~/.ssh/config
now just type ssh <alias-name>
41. SSH login without password
ssh-keygen ssh-copy-id -i root@ip_address # enter login password when prompted
Then just type ssh root@ip_address and you’ll be logged in automatically
42. cmatrix
Once cmatrix is installed, you can run it by typing cmatrix on the command line. When you do, you’ll get a screen like this. It’s just a cool effect. You can use this as a screensaver for your terminal when you leave it idle.
43. Command history
export HISTTIMEFORMAT="%d/%m/%y %T " # Add this to ~/.bashrc source ~/.bashrchistory
44. Check the top n files that are eating out your space
du -hsx * | sort -rh | head -<insert number n> du -hsx * | sort -rh | head -11
45. Get Statistics related to a file
stat filename.extension
46. Learn a random Linux command
man $(ls /bin | shuf | head -1)
47. Conditional Execution
To run two commands, one after successfully completing the other, put both commands on the same line, separated by a &&, or double ampersand
You can use the sleep command with does a countdown from the number of seconds given to complete ,as a time delay for a second command
sleep 100 && <insert second command>
48. Dealing with jobs and processes
Let’s assume you have a process that takes time to complete and doesn’t allow you to do anything else in the terminal. You can hit Ctrl+z and temporarily suspend it.
bg # This will make the suspended process run in background fg # To bring it back to the foreground jobs # This will give a list of processes with an integer id fg %<number> # if you want to foreground an older process bg %<number> # if you want an older process in the background
49. Repeat previous argument
!$ or "Esc + ."
50. Run Commands At a Specific Time
With the at command, you can specify a date and time. Doing so will open up an input prompt where you can enter a sequence of commands to be run at the date and time you gave. When you’re done, type Ctrl + D to quit the input prompt.
at 10:30 PM 15/07/20
If you this error when attempting to set new at jobs:
Can’t open /var/run/atd.pid to signal atd. No atd running?
sudo service atd start
51. xargs
xargs is an essential tool which enhances functionality of front line commands like find, grep or cut and gives more power to your shell script
This command can be used with any command which generates a long list of inputs. It was initially use to avoid “Argument list too long” errors and by using xargs you send sub-list to any command which is shorter than “ARG_MAX” and that’s how xargs avoid “Argument list too long” error
- It doesn’t handle files which has newlines or white space in its name and to avoid this problem one should always use “xargs -0”. xargs -0(Zero) changes separator to null character so its important that input feed to xargs is also use null as separator.
- The default command executed by xargs is /bin/echo and it will simply display file names.
- By default end of file string is “_” and if this string occurs in input the rest of input is ignored by xargs. Though you can change end of file string by using option “-eof”.
- We can force xargs to use at most max-args arguments per command line with -n <number> after xargs
<previous command> | xargs -0 -I X <another command> X
52. Downloading youtube playlist using youtube-dl
pip install -upgrade youtube-dl youtube-dl -i --yes-playlist --playlist-start 1 --write-thumbnail --write-auto-sub --sub-format srt --format mp4 -o "%(playlist_index)s-%(title)s.%(ext)s" <insert playlist link>
53. Split Folder with many files into small sub folders in order
Let’s say your you have a directory with 101,834 files and you want them in smaller sets of 20,000 each so that you don’t run into memory errors when you use the data for some algorithm.
You can use the following to batch it and run on small subsets
In this example the main directory is called dir and the batches are going to be named subdir1, subdir2,…,subdir5.
ls dir|head -n 20000 | xargs -I X cp dir/X subdir1 ls dir|tail -n +20001 | head -n 20000 | xargs -I X cp dir/X subdir2 ls dir|tail -n +40001 | head -n 20000 | xargs -I X cp dir/X subdir3 ls dir|tail -n +60001 | head -n 20000 | xargs -I X cp dir/X subdir4 ls dir|tail -n +80001 | head -n 20834 | xargs -I X cp dir/X subdir5
54. Untar a file
tar xvzf file.tar.gz
x: This tells tar to extract the files.
v: This option will list all of the files one by one in the archive. The “v” stands for “verbose.”
z: The z option is very important and tells the tar command to uncompress the file (gzip).
f: This options tells tar that you are going to give it a file name to work with.
sudo apt-get install dtrx dtrx file.tar.gz dtrx file.tar.bz2
55. Check your architecture
Using the following command, you can get your PC architecture.
getconf LONG_BIT
56. Answer bot using yes & no commands
It’s like an answer bot for those commands which require the user to say yes.
Y using the yes command:
yes | apt-get update
Or maybe you want to automate saying no; this can be done using the following command:
yes no | command
57. Create a file with a specific size
Use the dd command to create a file with a specific size:
dd if=/dev/zero of=out.txt bs=1M count=10
This will create a file with a 10-megabyte size filled with zeros.
58. Run the last command as root
Sometimes you forget to type sudo before your command that requires root privileges to run, you don’t have to rewrite it, just type:
sudo !!
59. Record your command-line session
If you want to record what you’ve typed in your shell screen, you can use the script command, which will save all of your typing to a file named typescript.
script
Once you type exit, all of your commands will be written to that file so you can review them later.
60. Replacing spaces with tabs
You can replace any character with any other character using the tr command, which is very handy.
cat education.txt | tr ':[space]:' '\t' > out.txt
This command will replace the spaces with tabs.
61. Convert character case
cat my_file | tr a-z A-Z > output.txt
This command converts the content of the file to upper case using the tr command.
62. Powerful xargs command
We can say that xargs command is one of the most essential Linux command line tricks, you can use this command to pass outputs between commands as arguments, for example, you may search for png files and compress them or do anything with them.
find . -name "*.png" -type f -print | xargs tar -cvzf pics.tar.gz
Or maybe you have a list of URLs in a file, and you want to download them or process them differently:
cat links.txt | xargs wget
The cat command result is passed to the end of the xargs command.
What if your command needs the output in the middle?
Just use {} combined with –i parameter to replace the arguments in the place where the result should go like this:
ls /etc/*.conf | xargs -i cp {} /home/edunews/Desktop/out
63. Keep executing a command until it succeeds
To keep executing a command until it finally succeeds, use the exit code of the command directly: while ! [command]; do sleep 1; done
$ while ! ./run.sh; do sleep 1; done cat: run.sh: No such file or directory cat: run.sh: No such file or directory linoxide.com
The command kept running until it found run.sh and printed out its content.
64. View progress of file transfers
In Linux, you cannot really know the rate of a file transfer progress until it’s done. Using the pv command, you can monitor the progress of file transfers.
$ pv access.log | gzip > access.log.gz 611MB 0:00:11 [58.3MB/s] [=> ] 15% ETA 0:00:59
65. Easily schedule events
Using the at command, you can easily schedule events at anytime.
echo wget https://sample.site/test.mp4 | at 2:00 PM
To view the queued jobs, type atq.
66. Compress, split and encrypt files
Trying to transfer large files across computers is a tedious task. We can easily do this by compressing the files and creating a multi-part archive if the files are extremely large. To encrypt, we add the -e switch.
$ zip -re test.zip AdbeRdr11010_en_US.exe run.sh Smart_Switch_pc_setup.exe Enter password: Verify password: adding: AdbeRdr11010_en_US.exe (deflated 0%) adding: run.sh (stored 0%) adding: Smart_Switch_pc_setup.exe (deflated 2%)
67. Stress test your battery
Do you want to check how long your battery can last under 100% CPU usage? Try this command:
$ cat /dev/urandom > /dev/null
68. Renaming/moving files with suffixes
If you want to quickly rename or move a bunch of files with suffix, try this command.
$ cp /home/sample.txt{,-old}
This will translate to:
$ cp /home/sample.txt /home/sample.txt-old
To rename files of a particular extension in batch, try this:
$ ls text_comes_here_1.txt text_comes_here_2.txt text_comes_here_3.txt text_comes_here_4.txt $ rename 's/comes_here_/goes_there/' *.txt $ls text_goes_there_1.txt text_goes_there_2.txt text_goes_there_3.txt
69. Replacement for id command
You can use awk in /proc/self/status to filter same results that id command gives
foo@localhost:/root$ awk -F: 'END {print "uid:"u" gid:"g" groups:"gg}{if($1=="Uid"){split($2,a," ");u=a[1]}if($1=="Gid"){split($2,a," ");g=a[1]}if($1=="Groups"){gg=$2}}' /proc/self/statusuid:1000 gid:1000 groups: 1000
70. Lock or Hide a File or Directory in Linux
The simplest way of locking a file or directory is by using Linux file permissions. In case your the owner of a file or directory, you can block (remove read, write and execute privileges) other users and groups from accessing it as follows:
To hide the file/directory from other system users, rename it with a (.) at the start of the file or directory:
71. Translate rwx Permissions into Octal Format in Linux
By default, when you run the ls command, it displays file permissions in rwx format, but to understand the equivalence of this format and the octal format, you can learn how to translate rwx permissions into Octal format in Linux.
72. How to Use ‘su’ When ‘sudo’ Fails
Although sudo command is used to execute commands with superuser privileges, there are moments when it fails to work as in the example below.
Here, I want to empty the contents of a large file named uptime.log but the operation has failed even when I used sudo.
In such as case, you need to switch to the root user account using su command to perform the operation like so:
73. Delete File Permanently in Linux
Normally, we use the rm command to delete files from a Linux system, however, these files do not completely get deleted, they are simply stored and hidden on the hard disk and can still be recovered these files in Linux and viewed by another person.
To prevent this, we can use the shred command which overwrites the file content and optionally deletes the file as well.
The options used in the above command:
- -z– adds a final overwrite with zeros to hide shredding.
- -u– helps to truncate and remove file after overwriting.
- -v– shows progress.
Read through shred man page for additional usage instructions:
74. Check for Spelling of Words in Linux
The look command displays lines beginning with a given string, it can help you to check for the spelling of word from within the command line. Although it is not so effective and reliable, look is still a useful alternative to other powerful spelling-checkers:
75. Search for Description of Keyword in Manual Page
The man command is used to display manual entry pages of commands, when used with the -k switch, it searches the short descriptions and manual page names for the keyword printf (such as adjust, apache and php in the commands below) as regular expression.
76. Watch Logs in Real-Time in Linux
With watch command, you can run another Linux command periodically while displaying its output on fullscreen and alongside tail command which is used to view the last parts of a file, it is possible to watch the recording of log entries in a logfile.
In the example below, you will watch the system authentication logfile. Open two terminal windows, display the log file for watching in real-time in the first window like so:
You can also use tail command which shows the last parts of a file. Its -f flag enables watching changes in a file in real-time, therefore it is possible to watch the recording of log entries in a log file.
And run the commands below in the second terminal as you observe the logfile content from the first window:
77. Find the right command
Executing the right command can be vital for your system. However in Linux there are so many different command lines that they are often hard to remember. So how do you search for the right command you need? The answer is apropos. All you need to run is:
# apropos <description>
Where you should change the “description” with the actual description of the command you are looking for. Here is a good example:
# apropos "list directory" dir (1) - list directory contents ls (1) - list directory contentsnt fsls (8) - list directory contents on an NTFS filesystem vdir (1) - list directory contents
78. Use midnight Commander
If you are not used to using commands such cd, cp, mv, rm than you can use the midnight command. It is an easy to use visual shell in which you can also use mouse:
F1 – F12 keys, you can easy perform different tasks. Simply check the legend at the bottom. To select a file or folder click the “Insert” button.
In short the midnight command is called “mc“. To install mc on your system simply run:
$ sudo apt-get install mc [On Debian based systems] # yum install mc [On Fedora based systems]
Here is a simple example of using midnight commander. Open mc by simply typing:
# mc
Now use the TAB button to switch between windows – left and right. I have a LibreOffice file that I will move to “Software” folder:
To move the file in the new directory press F6 button on your keyboard. MC will now ask you for confirmation:
Once confirmed, the file will be moved in the new destination directory.
79. Shutdown Computer at Specific Time
Sometimes you will need to shutdown your computer some hours after your work hours have ended. You can configure your computer to shut down at specific time by using:
$ sudo shutdown 21:00
This will tell your computer to shut down at the specific time you have provided. You can also tell the system to shutdown after specific amount of minutes:
$ sudo shutdown +15
That way the system will shut down in 15 minutes.
80. Show Information about Known Users
You can use a simple command to list your Linux system users and some basic information about them. Simply use:
# lslogins
81. Build Directory Trees with one Command
You probably know that you can create new directories by using the mkdir command. So if you want to create a new folder you will run something like this:
# mkdir new_folder
But what, if you want to create 5 subfolders within that folder? Running mkdir 5 times in a row is not a good solution. Instead you can use -p option like that:
# mkdir -p new_folder/{folder_1,folder_2,folder_3,folder_4,folder_5}
In the end you should have 5 folders located in new_folder:
# ls new_folder/ folder_1 folder_2 folder_3 folder_4 folder_5
82. Deleting Larger Files
Sometimes files can grow extremely large. I have seen cases where a single log file went over 250 GB large due to poor administrating skills. Removing the file with rm utility might not be sufficient in such cases due to the fact that there is extremely large amount of data that needs to be removed. The operation will be a “heavy” one and should be avoided. Instead, you can go with a really simple solution:
# > /path-to-file/huge_file.log
Where of course you will need to change the path and the file names with the exact ones to match your case. The above command will simply write an empty output to the file. In more simpler words it will empty the file without causing high I/O on your system.
Useful Command Line Keyboard Shortcuts
The following keyboard shortcuts are useful and will save you time:
- CTRL+U: Cuts text up until the cursor.
- CTRL+K: Cuts text from the cursor until the end of the line.
- CTRL+Y: Pastes text.
- CTRL+E: Moves the cursor to the end of the line.
- CTRL+A: Moves the cursor to the beginning of the line.
- ALT+F: Jumps forward to the next space.
- ALT+B: Skips back to the previous space.
- ALT+Backspace: Deletes the previous word.
- CTRL+W: Cuts the word behind the cursor.
- Shift+Insert: Pastes text into a terminal.
So that the commands above make sense, look at the next line of text.
sudo apt-get intall programname
There’s a spelling error in the command, and for the command to work, intall needs to be changed to install.
Imagine the cursor is at the end of the line. There are several ways to get back to the word install to change it.
You could press ALT+B twice, which would put the cursor in the following position (denoted by the ^ symbol):
sudo apt-get^install programname
Then, press the cursor key and insert the s into install.
Another useful command is Shift+Insert, especially if you need to copy text from a browser into the terminal.
| Shorcut | Description |
| Long press on Super (Windows key) | Opens up help for the most common keyboard shortcuts |
| Alt+Left Mouse Click | Allows to moves the current window |
Using the console
To open a console open the ‘Dash’ and type in ‘Terminal’. Alternatively you can use the shortcut Ctrl+Alt+T.
This opens a console window which allows you to issue commands.
Using the vim command line editor
Ubuntu offers several editors which are installed by default. The most common command line editor is vim.
To install vim on your Ubuntu machine use the following command.
sudo apt-get install vim
Start vim from the command line. vim has two modes, one editing mode and other mode in which you can move within the file.
Here is a minimal command reference for vim:
- i– Enter interactive mode to edit the file
- Escape– Leave interactive mode
- /– Search in file
- :wq– Saves the file and exists vim
- :q!– Exists vim without saving
Find files
The following demonstrates the usage of the find command.
| Command | Description |
| find dir -name “pattern” 2>/dev/null | Finds all files which recursively apply to the pattern “pattern” starting from the directory “dir”. The 2> sends all error messages to the null device. |
| find . -name ‘*.java’ -newer build.xml -print | Search for all java files newer than the file build.xml |
| find . -name ‘*.java’ -mtime +7 -print | Search for all java files newer than 7 dates |
| find . -name ‘*.java’ -mtime +7 -print0 | xargs -0 grep ‘swt’ |
The find command can also be combined with the grep command
Change owner of files and directories
| Command | Description |
| chown -R www-data:www-data mydir | Change recursively the owner and the group of the directory “mydir” and its subdirectories. |
Creating links
You can create a soft link to a file or directory using the following command.
# Create a new soft link via # ln -s target link # For example ln -s ~/workspace/e4-dev e4tools
Environment Variables
| Command | Description |
| echo $VARIABLE | Prints the content of the environment variable |
| sudo /etc/init.d/tomcat5 start/stop | Starts / stops the tomcat server |
| sudo -i | Switches to root |
Important files
| File | Description |
| /etc/issue | Contains the Ubuntu version you are running |
| lsb_release -a | Prints out the Ubuntu version you are running |
| /etc/apt/sources.list | Contains the available sources for software installation |
| /usr/share/tomcat | Installation directory for tomcat |
| /var/www/vhosts/domain1 | Contains on my v-server the user directory for a specific domain which is hosted on this server |
Package management
On the command line Ubuntu allows to install / remove and search for packages via the following commands.
| Command | Description |
| sudo apt-get install paketname | Installs a package |
| apt-cache search openjdk | Search for all packages which contain openjdk. The found package can get installed via the “apt-get install” command. |
| apt-cache show eclipse | Write down the meta-data of a package, e.g., the package description and the package maintainer |
| sudo apt-get remove package | Removes a package but leave the configuration data active |
| sudo apt-get purge package | Removes a package and orphaned dependencies and its configuration files |
| sudo apt-get update | Update the local package list |
| sudo apt-get upgrade | Updates any installed packages for which an update is available. Will not install new packages or remove packages to satisfy dependencies. |
| sudo apt-get dist-upgrade | Install available updates for the Ubuntu release you already have installed. Also installs new packages or removes existing packages to satisfy dependencies. |
| dpkg -L packagename | Lists all files and their location in a package |
| sudo updatedb; locate javac | Updates the installation database and locates the javac command. |
To search for the installed packages use the following command.
cat /var/log/dpkg.log | grep "\ install\ "
I hope this post helps you to understand all the “Linux Shortcuts and Tricks”. Any that you use in Linux and i forget in this post please do comment in the below comment section.
Keep learning 🙂
