How to run sh file in linux

Запуск скрипта sh в Linux

Вся сила Linux в использовании терминала. Это такая командная оболочка, где вы можете выполнять различные команды, которые будут быстро и эффективно выполнять различные действия. Ну впрочем, вы наверное это уже знаете. Для Linux было создано множество скриптов, которые выполняются в различных командных оболочках. Это очень удобно, вы просто объединяете несколько команд, которые выполняют определенное действие, а затем выполняете их одной командой или даже с помощью ярлыка.

Как работают скрипты

В Linux почти не используется расширение файла для опережения его типа на системном уровне. Это могут делать файловые менеджеры и то не всегда. Вместо этого, используются сигнатуры начала файла и специальные флаги. Система считает исполняемыми только те файлы, которым присвоен атрибут исполняемости.

Запуск скрипта sh в Linux

Сначала рассмотрим пример небольшого sh скрипта:

#!/bin/bash
echo «Hello world»

chmod ugo+x script.sh

Или полный путь от корня:

cp script.sh /usr/local/bin/script.sh

Теперь вы можете выполнить:

А если нам нужно запустить скрипт на php, то выполните:

Вот так все просто здесь работает. Так можно запустить скрипт как фоновый процесс, используйте символ &:

Даже запустить процесс linux не так сложно.

Выводы

how to run a script (.sh) file in linux from command line

Scripts are an integral part of any Linux or Unix systems. It refers to a piece of non-compiled programming code that requires an interpreter at run time to perform a task. The scripts can use any of the interpreted language such as Linux shell, Perl, Python, Ruby, JavaScript or any of the other hundreds of interpreted computer languages.

In linux shell environment, the script file usually have the .sh extension and is also referred to as the sh files. Sometimes, the files have extension specific to the shell that it is intended to run in, such as .bash, .csh or .ksh.

Scripts or Script files are used for a variety of purposes in Linux. Some Linux commands themselves are coded as scripts where as many of the compiled commands have several wrappers written around them to provide more convenience features. In addition, you can code your own custom script to automate many small tasks that needs to performed routinely. Also, many of the software have installer scripts that need to be run manually to install and configure products.

Shell scripts are Linux/Unix specific scripts that are designed and coded to run exclusively using the shell scripting languages available in Linux, such as sh, bash, csh, ksh etc. We will look at how to run these scripts, exclusively shell scripts (.sh files) from the command line.

In order to run the script file, you will need the appropriate permissions to execute it. If the execution bit is not set, then you should change the permissions on the script files using the chmod command.

chmod +x /path/to/scriptfile

The script files by convention have a .sh extension, but it is not necessary to have .sh extension or any extension for that matter. You can make any file (with any or no extension) executable by changing the permissions, and as long as the file content has the appropriate code that can be interpreted and executed by the shell, it should work just fine.

Run Script from Command Line

You can run the script by just typing in the name of the script, but that effectively depends on the PATH environment variable that set on the command shell. In order to make it independent of the variable settings, you can provide the path to the script file. You can provide either the relative path or the absolute path.

The generic syntax looks like this….

An example of relative path

and absolute path…

As mentioned, if the directory where the script file resides is in the PATH variable, then it is not necessary to provide the path to the file. You can just type in the script name and the shell will search all the directories in the path in order and execute the first one it finds.

A shell script can be executed in or using any of the supported shell environment in Linux. In a properly coded script, the first line or the shebang specifies exactly which shell to be used while executing the file. A Shebang or Shabang is usually the first line that looks something like…

The command line shell will fork a process/sub-shell with the specified value and execute the script in the sub-shell. This helps to keep the current shell clean. This is the ideal way to execute the script in most cases, such as when you are installing a product or executing a command.

But many times, you would want the script to execute in the command line shell without forking a sub-shell. This is especially useful, when the script modifies some environment values (such as path) that you want to continue to use even after the script exists.

Run Script using the Current Shell

Another advantage when executing the script this way, either using source or the dot operator is that you don’t need the executable permissions for the file, just the read permission will suffice. This can be quite handy if you cannot modify the permissions for file for some reason.

Run Script using Another Shell

Sometimes, you will want to run the script using another shell rather than the one you are using in the command window. This is also one way to override the value that is set in the shebang of the script file.

You type the shell you want to execute followed by the script file name to execute the script. For example, to run the script named myscript.sh using the sh shell, you will use the following command

or to use bash or ksh, just type

bash$ bash /path/to/myscript.sh

bash$ ksh /path/to/myscript.sh

Common mistakes and Troubleshooting

If you still cannot get a script to execute correctly, then you will need to troubleshoot. Most often, the error message should provide you with enough information to figure it out.

Check Permissions: If the script file or the user does not enough permissions to execute the file, the error message should be informative enough. You will see something like

You can modify the permissions of the script to give yourself the rights and you are good to go.

Check Path: The PATH variable is another cause for confusion especially if you are trying execute the script with out the full path. You can find the current PATH value by using the following command…

You should make sure that the directory that the script file resides in is in the path. Also, make sure that there is not another script with the same name in another directory that is getting picked up first. The shell executes the first script it finds in the path.

How do I open this file in the terminal?

16 Answers 16

Give execute permission to your script:

And to run your script:

You need to mark shell scripts as executable to run them from the file manager:

In the Permissions tab, check Allow executing file as program:

Close the Properties window and double-click the file. A dialog will pop up giving you the option to run the script in a terminal:

Prerequisite

Warning

Make sure you trust the source where you got the file from. It could be a virus.

The very simple way

This has problem. The terminal will close immediately and you will not be able to see the output.

The simple way

The way professionals do it

Once you can see for example script1.sh with ls run this:

Why do it the complicated way?

or you can run and redirect the output to a file:

or you can filter the output for keywords (e.g. «apples») an then redirect to a file:

There are thousands of things you can to to that file just by typing a few commands.

Another one, you can download a file from the Internet with one simple command:

And then open the file like this:

On Ubuntu 13.04 executable files opened in Nautilus are now opened in gedit by default rather than prompting the user to execute them. To enable the classic behavior you need to adjust the preferences:

Nautilus → Edit menu → Preferences → Behaviour tab → Click the radio button near Ask each time.

first do pwd to figure out where you are, and if it returns /home/username (where username is your real username), you can run

If you seem to be somewhere else, you can use the absolute path

these are all ways of describing the same place. Once you’ve made it to the location of your script, type

If your script has been written correctly it will run without errors.

Here’s a live example:

How To Run Bash Script In Linux?

The true power of a Bash script is utilized when it is run. But how to do that? Well, there are a plethora of ways to run a Bash script( shell script). Some of them may be useful in certain conditions, while it doesn’t matter how you run the script. Bash scripts are usually executed in the terminal or command-line interface.

To run a Bash script there are many ways. Some of them are given below:

For making some of these methods work, the script must have a shebang as the header to indicate it’s a shell script or bash script in this case. So, be sure to include the command below at the top of the file.

This command will make the script run under the bash interpreter. It is recommended to write the shebang header even if it works without them.

Using bash or sh

This is the most standard way of executing the bash script. You must have git bash installed if you are using Windows. For Linux and macOS, bash is installed by default. In this method, we type bash followed by the file name with extension i.e. sh in this case. In a terminal, run the following code by replacing the filename with your bash script filename.

Here, bash is a program that contains the shell environments necessary to run the script from the bash shell. So this will execute the script from the bash interpreter.

Using bash command to run the script.

We can also use sh to run the script as it will direct to the default shell in the setup environment.

Using the sh command to run the bash script.

From the above example, we were able to run a bash script using bash as well as the sh command. If you are not in the same folder/directory as the script, make sure you specify the relative path to the script.

Using source

This method is quite easy to run a bash script, and all of them are quite simple. We just need to type in “source” before the file/script name with an extension. In a terminal, run the following code by replacing the filename with your bash script filename.

The script will simply get executed after “sourcing” the file. The source command will execute the shell script as the default bash command provided you are in the bash shell. You need to be in the bash shell to execute the script using the source command.

Using Source to run a bash script

From the screenshot of the script running, we can see that the source works exactly like the bash or sh command. The above script is a very basic script, but that doesn’t matter as long as the script is errorless and bug-free. Also, you need to add the relative path here as well if you are not in the same directory as the bash script.

By specifying the path to the script and chmod

This is a standalone method to run a bash script. We have to execute the script as an executable, we can run the script anywhere provided we have a bash shell somewhere in the environment. To make it executable we need to make sure we have the rights to run the file as an executable. We will use chmod for changing the rights on the file/script. In a terminal, run the following code by replacing the filename with your bash script filename.

The above command will allow us to execute the file. So it changes the mode of the file, the file should be read-only, executable, or any other mode for files. If you are using Linux and are not the root user, simply use sudo before the command chmod. The +x command will make sure the file is executable by everyone in the environment.

After the permission of the file is taken care of, we can now simply execute the file as follows. The command below takes into consideration that you are in the same directory as the file/ bash script is in.

If you are not on the same path as the bash script, make sure you provide the relative path to the file or the bash script.

using chmod and executing the script.

Executing a script from a relative path.

The above snippets and screenshots show that we can run the scripts in a bash environment by changing the mode of the file using the chmod.

From the following guide, we were able to run scripts in Linux using various methods and programs. So, those were some methods to run a bash script on Linux or pretty much anywhere.

How to Run a Shell Script in Linux [Essentials Explained for Beginners]

There are two ways to run a shell script in Linux. You can use:

Or you can execute the shell script like this:

That maybe simple, but it doesn’t explain a lot. Don’t worry, I’ll do the necessary explaining with examples so that you understand why a particular syntax is used in the given format while running a shell script.

I am going to use this one line shell script to make things as uncomplicated as possible:

Method 1: Running a shell script by passing the file as argument to shell

The first method involves passing the script file name as an argument to the shell.

Considering that bash is the default shell, you can run a script like this:

Do you know the advantage of this approach? Your script doesn’t need to have the execute permission. Pretty handy for quick and simple tasks.

» data-medium-file=»https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux-300×133.png» data-large-file=»https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux.png» width=»741″ height=»329″ src=»https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux.png» alt=»Run A Shell Script Linux» data-lazy-srcset=»https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux.png 741w, https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux-300×133.png 300w, https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux-100×44.png 100w, https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux-150×67.png 150w» data-lazy-sizes=»(max-width: 741px) 100vw, 741px» data-lazy-src=»https://itsfoss.com/wp-content/uploads/2021/01/run-a-shell-script-linux.png?is-pending-load=1″ srcset=»data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7″> Running a Shell Script Linux

If you are not familiar already, I advise you to read my detailed guide on file permission in Linux.

Keep in mind that it needs to be a shell script that you pass as argument. A shell script is composed of commands. If you use a normal text file, it will complain about incorrect commands.

» data-medium-file=»https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script-300×133.png» data-large-file=»https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script.png» width=»741″ height=»329″ src=»https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script.png» alt=»Running Text File As Script in Linux» data-lazy-srcset=»https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script.png 741w, https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script-300×133.png 300w, https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script-100×44.png 100w, https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script-150×67.png 150w» data-lazy-sizes=»(max-width: 741px) 100vw, 741px» data-lazy-src=»https://itsfoss.com/wp-content/uploads/2021/01/running-text-file-as-script.png?is-pending-load=1″ srcset=»data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7″> Running a Text File As Script

In this approach, you explicitly specified that you want to use bash as the interpreter for the script.

Shell is just a program and bash is an implementation of that. There are other such shells program like ksh, zsh, etc. If you have other shells installed, you can use that as well instead of bash.

For example, I installed zsh and used it to run the same script:

» data-medium-file=»https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh-300×102.png» data-large-file=»https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh.png» width=»741″ height=»253″ src=»https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh.png» alt=»Execute Shell Script With Zsh» data-lazy-srcset=»https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh.png 741w, https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh-300×102.png 300w, https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh-100×34.png 100w, https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh-150×51.png 150w» data-lazy-sizes=»(max-width: 741px) 100vw, 741px» data-lazy-src=»https://itsfoss.com/wp-content/uploads/2021/01/execute-shell-script-with-zsh.png?is-pending-load=1″ srcset=»data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7″> Execute Shell Script With Zsh

Recommended Read:

How to Run Multiple Linux Commands at Once in Linux Terminal [Essential Beginners Tip]

Method 2: Execute shell script by specifying its path

The other method to run a shell script is by providing its path. But for that to be possible, your file must be executable. Otherwise, you’ll have “permission denied” error when you try to execute the script.

So first you need to make sure that your script has the execute permission. You can use the chmod command to give yourself this permission like this:

Once your script is executable, all you need to do is to type the file name along with its absolute or relative path. Most often you are in the same directory so you just use it like this:

If you are not in the same directory as your script, you can specify it the absolute or relative path to the script:

» data-medium-file=»https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory-300×103.png» data-large-file=»https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory.png» width=»795″ height=»272″ src=»https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory.png» alt=»Running Shell Script In Other Directory» data-lazy-srcset=»https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory.png 795w, https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory-300×103.png 300w, https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory-768×263.png 768w, https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory-100×34.png 100w, https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory-150×51.png 150w» data-lazy-sizes=»(max-width: 795px) 100vw, 795px» data-lazy-src=»https://itsfoss.com/wp-content/uploads/2021/01/running-shell-script-in-other-directory.png?is-pending-load=1″ srcset=»data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7″> Running Shell Script In Other Directory

» data-medium-file=»https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux-300×169.png» data-large-file=»https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux.png» width=»800″ height=»450″ src=»https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux.png» alt=»Executing Shell Scripts Linux» data-lazy-srcset=»https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux.png 800w, https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux-300×169.png 300w, https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux-768×432.png 768w, https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux-100×56.png 100w, https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux-150×84.png 150w» data-lazy-sizes=»(max-width: 800px) 100vw, 800px» data-lazy-src=»https://itsfoss.com/wp-content/uploads/2021/01/executing-shell-scripts-linux.png?is-pending-load=1″ srcset=»data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7″>

Why can you not use the script name when you are in the same directory? That is because your Linux systems looks for the executables to run in a few selected directories that are specified in the PATH variable.

Here’s the value of PATH variable for my system:

This means that any file with execute permissions in one of the following directories can be executed from anywhere in the system:

The binaries or executable files for Linux commands like ls, cat etc are located in one of those directories. This is why you are able to run these commands from anywhere on your system just by using their names. See, the ls command is located in /usr/bin directory.

» data-medium-file=»https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux-300×103.png» data-large-file=»https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux.png» width=»795″ height=»272″ src=»https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux.png» alt=»Locating Command Linux» data-lazy-srcset=»https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux.png 795w, https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux-300×103.png 300w, https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux-768×263.png 768w, https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux-100×34.png 100w, https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux-150×51.png 150w» data-lazy-sizes=»(max-width: 795px) 100vw, 795px» data-lazy-src=»https://itsfoss.com/wp-content/uploads/2021/01/locating-command-linux.png?is-pending-load=1″ srcset=»data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7″>

When you specify the script WITHOUT the absolute or relative path, it cannot find it in the directories mentioned in the PATH variable.

Why most shell scripts contain #! /bin/bash at the beginning of the shell scripts?

Remember how I mentioned that shell is just a program and there are different implementations of shells.

Does it matter? It could. See, most of the shell syntax is common in all kind of shell but some might differ.

For example, the array behavior is different in bash and zsh shells. In zsh, the array index starts at 1 instead of 0.

» data-medium-file=»https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh-300×146.png» data-large-file=»https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh.png» width=»795″ height=»386″ src=»https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh.png» alt=»Bash Vs Zsh» data-lazy-srcset=»https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh.png 795w, https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh-300×146.png 300w, https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh-768×373.png 768w, https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh-100×49.png 100w, https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh-150×73.png 150w» data-lazy-sizes=»(max-width: 795px) 100vw, 795px» data-lazy-src=»https://itsfoss.com/wp-content/uploads/2021/01/bash-vs-zsh.png?is-pending-load=1″ srcset=»data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7″> Bash Vs Zsh

Using #! /bin/bash indicates that the script is bash shell script and should be run with bash as interpreter irrespective of the shell which is being used on the system. If you are using zsh specific syntax, you can indicate that it is zsh script by adding #! /bin/zsh as the first line of the script.

The space between #! /bin/bash doesn’t matter. You can also use #!/bin/bash.

Was it helpful?

I hope this article added to your Linux knowledge. If you still have questions or suggestions, please leave a comment.

Expert users can still nitpick this article about things I missed out. But the problem with such beginner topics is that it is not easy to find the right balance of information and avoid having too much or too few details.

If you are interested in learning bash script, we have an entire Bash Beginner Series on our sysadmin focused website Linux Handbook. If you want, you may also purchase the ebook with additional exercises to support Linux Handbook.

Creator of It’s FOSS. An ardent Linux user & open source promoter. Huge fan of classic detective mysteries ranging from Agatha Christie and Sherlock Holmes to Detective Columbo & Ellery Queen. Also a movie buff with a soft corner for film noir.