Locating commands in linux

10 Useful ‘locate’ Command Practical Examples for Linux Newbies

One of most obnoxious experiences that most new users of the Linux platform usually face is the inability to find the simplest and yet more effective means of looking up files on their system.

Linux, like almost any other operating system, utilizes several mechanisms to answer search queries for users. Two of the most popular file searching utilities accessible to users are called find and locate.

Now, it is important to note that both search processes work extremely well but nonetheless, the center of this article will be more on the locate utility, which is the more convenient of the two as it uses more efficient ways to quickly process queries inputted by the users.

The locate utility works better and faster than it’s find counterpart because instead of searching the file system when a file search is initiated – Something find does – locate would look through a database. This database contains bits and parts of files and their corresponding paths on your system.

Here are ten simple locate commands to set you up in becoming more productive with your Linux machine.

1. Using locate Command

Firing locate command to look for a file is pretty easy and straightforward. All you need to do is type:

2. Limit Search Queries to a Specific Number

You can limit your search returns to a required number to avoid redundancy with your search results using the -n command.

For example, if you want just 20 results from your queries, you can type the following command:

The results will show the first 20 files that end with .html .

3. Display The Number of Matching Entries

If you want to display the count of all matching entries of file “tecmint“, use the locate -c command.

4. Ignore Case Sensitive Locate Outputs

By default, locate is configured to process queries in a case sensitive manner meaning TEXT.TXT will point you to a different result than text.txt .

To have locate command ignore case sensitivity and show results for both uppercase and lowercase queries, input commands with the -i option.

5. Refresh mlocate Database

Since locate command relies on a database called mlocate. The said database needs to be updated regularly for the command utility to work
efficiently.

To update the mlocate database, you use a utility called updatedb. It should be noted that you will need superuser privileges for this to work properly, is it needs to be executed as root or sudo privileges.

6. Display Only Files Present in Your System

When you have an updated mlocate database**, locate command still produces results of files whose physical copies are deleted from your system.

To avoid seeing results of files not present in your machine at the time of punching in the command, you will need to use the locate-e command. The process searches your system to verify the existence of the file you’re looking for even if it is still present in your mlocate.db.

7. Separate Output Entries Without New Line

locate command’s default separator is the newline (\\n) character. But if you prefer to use a different separator like the ASCII NUL, you can do so using the -0 command line option.

8. Review Your Locate Database

If you’re in doubt as to the current status of your mlocate.db, you can easily view the locate database statistics by using the -S command.

9. Suppress Error Messages in Locate

Constantly trying to access your locate database does sometimes yield unnecessary error messages stating that you do not have the required privileges to have root access to the mlocate.db, because you’re only a normal user and not the required Superuser.

To completely do away with these message, use the -q command.

10. Choose a Different mlocate Location

If you’re inputting queries looking for results not present in the default mlocate database and want answers from a different mlocate.db located somewhere else in your system, you can point the locate command to a different mlocate database at a different part of your system with the -d command.

locate command might seem like one of those utilities that does everything you asked it to do without much of a hustle but in truth, in order for the process to keep its efficiency, the mlocate.db needs to be fed with information every now and then. Failure to do so might render the program a bit useless.

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Linux / UNIX: Determine where a binary command is stored / located on file system

You can use “type” or “whereis” command to find out which command shell executes and to print binary (command) file location for specified command.

whereis command example

Display ls command location along with man page path:
whereis ls
Output:
ls: /bin/ls /usr/share/man/man1p/ls.1p.gz /usr/share/man/man1/ls.1.gz

type command example

Find out which command the shell executes:
type -a ls
Output:
ls is aliased to `ls –color=tty’
ls is /bin/ls

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Category	List of Unix and Linux commands
Documentation	help • mandb • man • pinfo
Disk space analyzers	df • duf • ncdu • pydf
File Management	cat • cp • less • mkdir • more • tree
Firewall	Alpine Awall • CentOS 8 • OpenSUSE • RHEL 8 • Ubuntu 16.04 • Ubuntu 18.04 • Ubuntu 20.04
Linux Desktop Apps	Skype • Spotify • VLC 3
Modern utilities	bat • exa
Network Utilities	NetHogs • dig • host • ip • nmap
OpenVPN	CentOS 7 • CentOS 8 • Debian 10 • Debian 8/9 • Ubuntu 18.04 • Ubuntu 20.04
Package Manager	apk • apt
Processes Management	bg • chroot • cron • disown • fg • glances • gtop • jobs • killall • kill • pidof • pstree • pwdx • time • vtop
Searching	ag • grep • whereis • which
Shell builtins	compgen • echo • printf
Text processing	cut • rev
User Information	groups • id • lastcomm • last • lid/libuser-lid • logname • members • users • whoami • who • w
WireGuard VPN	Alpine • CentOS 8 • Debian 10 • Firewall • Ubuntu 20.04

Comments on this entry are closed.

If for some reason the command you are looking for is not in your PATH you can try the locate command to find out where it might be located

i access my server through sshd using putty but after a certain period of time the port on which sshd is open is closed automatically.
i am not able to figure out this problem.
please help me thanks in advance

How to know the virsion of a binary file in UNIX?
Need unix command for the same.

Typically programs have a version command line option to print the version number. Try running ‘program -v’ or ‘program –version’. Some binary files on your system are actually a link to a specific version of that program. For example, on my system, /usr/bin/python is a link to python-2.7, so I know that I have python version 2.7. (to see if a file is a link run ‘ls -l /path/to/file’ and it will have a ‘l’ at the beginging of the line, and have an arrow at the end followed by the file that the link points to).

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35 Linux Basic Commands Every User Should Know

When hearing about Linux, most people think of a complicated operating system that is only used by programmers. But it’s not as scary as it seems.

Linux is an entire family of open-source Unix operating systems, that are based on the Linux Kernel. This includes all of the most popular Linux based systems like Ubuntu, Fedora, Mint, Debian, and others. More accurately, they’re called distributions or distros.

Since Linux was first released in 1991, it has continued to gain popularity due to its open-source nature. People can freely modify and redistribute it under their own name.

When operating a Linux OS, you need to use a shell — an interface that gives you access to the operating system’s services. Most Linux distributions use a graphic user interface (GUI) as their shell, mainly to provide ease of use for their users.

That being said, it’s recommended to use a command-line interface (CLI) because it’s more powerful and effective. Tasks that require a multi-step process through GUI can be done in a matter of seconds by typing commands into the CLI.

So if you’re considering using Linux, learning basic command lines will go a long way. In this article, you’ll learn 35 basic Linux commands that will undoubtedly help you navigate through Linux as a newbie.

Linux Basic Commands

Before we go on to the list of commands, you need to open the command line first. If you are still unsure about the command-line interface, check out this CLI tutorial.

Although the steps may differ depending on the distribution that you’re using, you can usually find the command line in the Utilities section.

Here is a list of basic Linux commands:

1. pwd command

Use the pwd command to find out the path of the current working directory (folder) you’re in. The command will return an absolute (full) path, which is basically a path of all the directories that starts with a forward slash (/). An example of an absolute path is /home/username.

2. cd command

To navigate through the Linux files and directories, use the cd command. It requires either the full path or the name of the directory, depending on the current working directory that you’re in.

Let’s say you’re in /home/username/Documents and you want to go to Photos, a subdirectory of Documents. To do so, simply type the following command: cd Photos.

Another scenario is if you want to switch to a completely new directory, for example,/home/username/Movies. In this case, you have to type cd followed by the directory’s absolute path: cd /home/username/Movies.

There are some shortcuts to help you navigate quickly:

• cd .. (with two dots) to move one directory up
• cd to go straight to the home folder
• cd- (with a hyphen) to move to your previous directory

On a side note, Linux’s shell is case sensitive. So, you have to type the name’s directory exactly as it is.

3. ls command

The ls command is used to view the contents of a directory. By default, this command will display the contents of your current working directory.

If you want to see the content of other directories, type ls and then the directory’s path. For example, enter ls /home/username/Documents to view the content of Documents.

There are variations you can use with the ls command:

• ls -R will list all the files in the sub-directories as well
• ls -a will show the hidden files
• ls -al will list the files and directories with detailed information like the permissions, size, owner, etc.

4. cat command

cat (short for concatenate) is one of the most frequently used commands in Linux. It is used to list the contents of a file on the standard output (sdout). To run this command, type cat followed by the file’s name and its extension. For instance: cat file.txt.

Here are other ways to use the cat command:

• cat > filename creates a new file
• cat filename1 filename2>filename3 joins two files (1 and 2) and stores the output of them in a new file (3)
• to convert a file to upper or lower case use, cat filename | tr a-z A-Z >output.txt

5. cp command

Use the cp command to copy files from the current directory to a different directory. For instance, the command cp scenery.jpg /home/username/Pictures would create a copy of scenery.jpg (from your current directory) into the Pictures directory.

6. mv command

The primary use of the mv command is to move files, although it can also be used to rename files.

The arguments in mv are similar to the cp command. You need to type mv, the file’s name, and the destination’s directory. For example: mv file.txt /home/username/Documents.

To rename files, the Linux command is mv oldname.ext newname.ext

7. mkdir command

Use mkdir command to make a new directory — if you type mkdir Music it will create a directory called Music.

There are extra mkdir commands as well:

• To generate a new directory inside another directory, use this Linux basic command mkdir Music/Newfile
• use the p (parents) option to create a directory in between two existing directories. For example, mkdir -p Music/2020/Newfile will create the new “2020” file.

8. rmdir command

If you need to delete a directory, use the rmdir command. However, rmdir only allows you to delete empty directories.

9. rm command

The rm command is used to delete directories and the contents within them. If you only want to delete the directory — as an alternative to rmdir — use rm -r.

Note: Be very careful with this command and double-check which directory you are in. This will delete everything and there is no undo.

10. touch command

The touch command allows you to create a blank new file through the Linux command line. As an example, enter touch /home/username/Documents/Web.html to create an HTML file entitled Web under the Documents directory.

11. locate command

You can use this command to locate a file, just like the search command in Windows. What’s more, using the -i argument along with this command will make it case-insensitive, so you can search for a file even if you don’t remember its exact name.

To search for a file that contains two or more words, use an asterisk (*). For example, locate -i school*note command will search for any file that contains the word “school” and “note”, whether it is uppercase or lowercase.

12. find command

Similar to the locate command, using find also searches for files and directories. The difference is, you use the find command to locate files within a given directory.

As an example, find /home/ -name notes.txt command will search for a file called notes.txt within the home directory and its subdirectories.

Other variations when using the find are:

• To find files in the current directory use, find . -name notes.txt
• To look for directories use, / -type d -name notes. txt

13. grep command

Another basic Linux command that is undoubtedly helpful for everyday use is grep. It lets you search through all the text in a given file.

To illustrate, grep blue notepad.txt will search for the word blue in the notepad file. Lines that contain the searched word will be displayed fully.

14. sudo command

Short for “SuperUser Do”, this command enables you to perform tasks that require administrative or root permissions. However, it is not advisable to use this command for daily use because it might be easy for an error to occur if you did something wrong.

15. df command

Use df command to get a report on the system’s disk space usage, shown in percentage and KBs. If you want to see the report in megabytes, type df -m.

16. du command

If you want to check how much space a file or a directory takes, the du (Disk Usage) command is the answer. However, the disk usage summary will show disk block numbers instead of the usual size format. If you want to see it in bytes, kilobytes, and megabytes, add the -h argument to the command line.

17. head command

The head command is used to view the first lines of any text file. By default, it will show the first ten lines, but you can change this number to your liking. For example, if you only want to show the first five lines, type head -n 5 filename.ext.

18. tail command

This one has a similar function to the head command, but instead of showing the first lines, the tail command will display the last ten lines of a text file. For example, tail -n filename.ext.

19. diff command

Short for difference, the diff command compares the contents of two files line by line. After analyzing the files, it will output the lines that do not match. Programmers often use this command when they need to make program alterations instead of rewriting the entire source code.

The simplest form of this command is diff file1.ext file2.ext

20. tar command

The tar command is the most used command to archive multiple files into a tarball — a common Linux file format that is similar to zip format, with compression being optional.

This command is quite complex with a long list of functions such as adding new files into an existing archive, listing the content of an archive, extracting the content from an archive, and many more. Check out some practical examples to know more about other functions.

21. chmod command

chmod is another Linux command, used to change the read, write, and execute permissions of files and directories. As this command is rather complicated, you can read the full tutorial in order to execute it properly.

22. chown command

In Linux, all files are owned by a specific user. The chown command enables you to change or transfer the ownership of a file to the specified username. For instance, chown linuxuser2 file.ext will make linuxuser2 as the owner of the file.ext.

23. jobs command

jobs command will display all current jobs along with their statuses. A job is basically a process that is started by the shell.

24. kill command

If you have an unresponsive program, you can terminate it manually by using the kill command. It will send a certain signal to the misbehaving app and instructs the app to terminate itself.

There is a total of sixty-four signals that you can use, but people usually only use two signals:

• SIGTERM (15) — requests a program to stop running and gives it some time to save all of its progress. If you don’t specify the signal when entering the kill command, this signal will be used.
• SIGKILL (9) — forces programs to stop immediately. Unsaved progress will be lost.

Besides knowing the signals, you also need to know the process identification number (PID) of the program you want to kill. If you don’t know the PID, simply run the command ps ux.

After knowing what signal you want to use and the PID of the program, enter the following syntax:

kill [signal option] PID.

25. ping command

Use the ping command to check your connectivity status to a server. For example, by simply entering ping google.com, the command will check whether you’re able to connect to Google and also measure the response time.

26. wget command

The Linux command line is super useful — you can even download files from the internet with the help of the wget command. To do so, simply type wget followed by the download link.

27. uname command

The uname command, short for Unix Name, will print detailed information about your Linux system like the machine name, operating system, kernel, and so on.

28. top command

As a terminal equivalent to Task Manager in Windows, the top command will display a list of running processes and how much CPU each process uses. It’s very useful to monitor system resource usage, especially knowing which process needs to be terminated because it consumes too many resources.

29. history command

When you’ve been using Linux for a certain period of time, you’ll quickly notice that you can run hundreds of commands every day. As such, running history command is particularly useful if you want to review the commands you’ve entered before.

30. man command

Confused about the function of certain Linux commands? Don’t worry, you can easily learn how to use them right from Linux’s shell by using the man command. For instance, entering man tail will show the manual instruction of the tail command.

31. echo command

This command is used to move some data into a file. For example, if you want to add the text, “Hello, my name is John” into a file called name.txt, you would type echo Hello, my name is John >> name.txt

32. zip, unzip command

Use the zip command to compress your files into a zip archive, and use the unzip command to extract the zipped files from a zip archive.

33. hostname command

If you want to know the name of your host/network simply type hostname. Adding a -i to the end will display the IP address of your network.

34. useradd, userdel command

Since Linux is a multi-user system, this means more than one person can interact with the same system at the same time. useradd is used to create a new user, while passwd is adding a password to that user’s account. To add a new person named John type, useradd John and then to add his password type, passwd 123456789.

To remove a user is very similar to adding a new user. To delete the users account type, userdel UserName

Bonus Tips and Tricks

Use the clear command to clean out the terminal if it is getting cluttered with too many past commands.

Try the TAB button to autofill what you are typing. For example, if you need to type Documents, begin to type a command (let’s go with cd Docu, then hit the TAB key) and the terminal will fill in the rest, showing you cd Documents.

Ctrl+C and Ctrl+Z are used to stop any command that is currently working. Ctrl+C will stop and terminate the command, while Ctrl+Z will simply pause the command.

If you accidental freeze your terminal by using Ctrl+S, simply undo this with the unfreeze Ctrl+Q.

Ctrl+A moves you to the beginning of the line while Ctrl+E moves you to the end.

You can run multiple commands in one single command by using the “;” to separate them. For example Command1; Command2; Command3. Or use && if you only want the next command to run when the first one is successful.

To Sum Up

Basic Linux commands help users execute tasks easily and effectively. It might take a while to remember some of the basic commands, but nothing is impossible with lots of practice.

In the end, knowing and mastering these basic Linux commands will be undoubtedly beneficial for you. Good luck!

Artūras is an experienced technical content writer. Bringing in a lot of knowledge about WordPress and web hosting to the team, he strives to write pristine content about any IT related subject. He also loves dogs.

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