Path linux all users

Переменная PATH в Linux

Когда вы запускаете программу из терминала или скрипта, то обычно пишете только имя файла программы. Однако, ОС Linux спроектирована так, что исполняемые и связанные с ними файлы программ распределяются по различным специализированным каталогам. Например, библиотеки устанавливаются в /lib или /usr/lib, конфигурационные файлы в /etc, а исполняемые файлы в /sbin/, /usr/bin или /bin.

Таких местоположений несколько. Откуда операционная система знает где искать требуемую программу или её компонент? Всё просто — для этого используется переменная PATH. Эта переменная позволяет существенно сократить длину набираемых команд в терминале или в скрипте, освобождая от необходимости каждый раз указывать полные пути к требуемым файлам. В этой статье мы разберёмся зачем нужна переменная PATH Linux, а также как добавить к её значению имена своих пользовательских каталогов.

Переменная PATH в Linux

Для того, чтобы посмотреть содержимое переменной PATH в Linux, выполните в терминале команду:

На экране появится перечень папок, разделённых двоеточием. Алгоритм поиска пути к требуемой программе при её запуске довольно прост. Сначала ОС ищет исполняемый файл с заданным именем в текущей папке. Если находит, запускает на выполнение, если нет, проверяет каталоги, перечисленные в переменной PATH, в установленном там порядке. Таким образом, добавив свои папки к содержимому этой переменной, вы добавляете новые места размещения исполняемых и связанных с ними файлов.

Для того, чтобы добавить новый путь к переменной PATH, можно воспользоваться командой export. Например, давайте добавим к значению переменной PATH папку/opt/local/bin. Для того, чтобы не перезаписать имеющееся значение переменной PATH новым, нужно именно добавить (дописать) это новое значение к уже имеющемуся, не забыв о разделителе-двоеточии:

Теперь мы можем убедиться, что в переменной PATH содержится также и имя этой, добавленной нами, папки:

Вы уже знаете как в Linux добавить имя требуемой папки в переменную PATH, но есть одна проблема — после перезагрузки компьютера или открытия нового сеанса терминала все изменения пропадут, ваша переменная PATH будет иметь то же значение, что и раньше. Для того, чтобы этого не произошло, нужно закрепить новое текущее значение переменной PATH в конфигурационном системном файле.

В ОС Ubuntu значение переменной PATH содержится в файле /etc/environment, в некоторых других дистрибутивах её также можно найти и в файле /etc/profile. Вы можете открыть файл /etc/environment и вручную дописать туда нужное значение:

sudo vi /etc/environment

Можно поступить и иначе. Содержимое файла .bashrc выполняется при каждом запуске оболочки Bash. Если добавить в конец файла команду export, то для каждой загружаемой оболочки будет автоматически выполняться добавление имени требуемой папки в переменную PATH, но только для текущего пользователя:

Выводы

В этой статье мы рассмотрели вопрос о том, зачем нужна переменная окружения PATH в Linux и как добавлять к её значению новые пути поиска исполняемых и связанных с ними файлов. Как видите, всё делается достаточно просто. Таким образом вы можете добавить столько папок для поиска и хранения исполняемых файлов, сколько вам требуется.

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How to Permanently Set $PATH in Linux

Understanding the $PATH Variable

In this tutorial, we will show you how to permanently set your PATH on Linux.

First off, why should you care?

The $PATH variable, or just PATH, without the $ indicating variables, specifies a list of directories that impacts your computing platform’s functionality in a critical way. This is because the $PATH is the list of directories in which the system searches for executable programs, scripts, or files.

Imagine trying to run the ssh command, for example, to connect to a server. What happens if the system cannot find the ssh program? You are unable to connect to servers and run computations. You have a plethora of useful programs, examples like python , javac , npm , make , chmod , apt-get and so on, that your computer needs to be able to find when you invoke them at the command line.

The $PATH variable is the key that makes it possible to find the correct program and execute it at your command without needing the executable’s full directory path. When your PATH is set incorrectly, your shell will be unable to find programs, and certain commands will fail.

Using bash_profile to Set your PATH

A common mistake with the $PATH variable is to set it in the current shell only, without persisting the change. When you open a new shell, the changes are lost, and you are once again unable to execute certain commands because those programs are not found in the PATH.

The first way of setting your $PATH permanently is to modify the $PATH variable in your Bash profile file, located at /home/ /.bash_profile .

For example, let’s say I want to add a new directory /home/tomahawk/tools/jdk1.8.0_92/bin to my PATH. You might recognize this as a Java Development Kit installation. However, that is beside the point. Whatever the directory contains, I can add it to our path and make the programs that this bin directory contains accessible from the command line by adding the following line to the end of the file

A good way to edit the file is to use nano , vi , vim or emacs . You can use the command sudo

/.bash_profile , and enter your admin password when prompted, then add that line to the end and save the file.

To activate the changes in the current shell, you have to «source» the updated bash_profile file. You do this with the command:

This simply imports the file’s settings into the current shell. Now every time you open your shell, your bash_profile will automatically be «sourced» and you won’t need to run this command every time.

Now we can invoke commands or programs in the new directory /home/tomahawk/tools/jdk1.8.0_92/bin , such as javac , located at /home/tomahawk/tools/jdk1.8.0_92/bin/javac by just typing at the command prompt the name of the program. We can do this now from any directory, because the PATH has been updated to look for executable programs in our new directory.

Now runs the correct javac program, printing out something like the following:

bash_profile is appropriate when you want to set a PATH variable customized for a single user of the system. If you wanted to set PATH for all users of a system, there are better ways to do so, which we cover further on in this guide.

Using bashrc to Set your PATH

Instead of setting the PATH in

/.bash_profile , we can also add the directories we want to the PATH in

/.bashrc instead. Setting the PATH in bashrc looks identical to how we set it in bash_profile .

For example, to include the directory /home/tomahawk/.rbenv/bin in my path, I edit or create the file /home/tomahawk/.bashrc , adding the following line:

Notice that, like last time, the first thing in our new PATH export is the inclusion of the existing $PATH variable. This ensures that we preserve the current value of PATH, and just add any additional directories on to the PATH, after the $PATH variable. If you do not do this, you will overwrite the PATH variable entirely, and miss critical directories the system needs to be on the PATH. As a result, your system can become unusable.

The difference between using bashrc and bash_profile is that bash_profile is used for login shells. These run when you login via the console, or log in using ssh . In contrast, once you are logged in, and you open a command shell or run the bash command, the bashrc file will run. Your PATH settings from bashrc will then be available.

The effect of setting the PATH is similar. In addition, we must activate any changes in the bashrc file into the current shell the first time we make this change, just as we did for the bash_profile file. This time, we run source

/.bashrc . We can now access the new PATH at the command line. It has been set permanently and will stay the same between multiple logins into the system.

Using a Profile File to Set your PATH

We can also set the PATH permanently using a user’s profile file. This is different from

/.bash_profile in that it is set not for shells only, but for all programs.

User profiles are loaded at login. The PATH variable can be set in the

To set my PATH to include everything already in $PATH, as well as a new directory /home/tomahawk/.exenv/bin , I edit the file at

/.profile and set the PATH as follows

As in all prior examples, we will need to source these changes to make them active for the current shell, but subsequent logins will persist the changes.

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Once that’s done, I can run the exenv command, which is one of the programs available in the folder I just added to the PATH, and I get back the output of my exenv version:

You can read more about the exenv program here, but you can use this process to set PATH permanently to include any program or directory you want.

Permanently Setting your PATH for Other Shells like ZSH and KSH

If you use alternative shells such as zsh, ksh and others, you can set the PATH permanently using those shells’ configuration.

Like bash, both zsh and ksh use a zshrc and khsrc file, respectively, to set the path for non-login shells. For login shells, they use the analogous shell profile files zprofile and kprofile.

You can therefore set the PATH permanently for these shells in a similar way to what we did for Bash. For zsh, you can find these files, or create them if they do not exist, at

Similarly, you can set PATH permanently for ksh in the configuration files located at

There are plenty of other shells you can use, such as the C Shell and the tcsh shell. Setting the PATH permanently for them will generally follow the pattern we have seen here.

Permanently Setting System-Wide PATH for all Users

System-wide settings for all users can be set in /etc/profile . There is considerable flexibility and multiple options for setting the PATH permanently system-wide.

Your Linux system will execute all script files ending in .sh in /etc/profile.d whenever a bash shell is entered, as well as when the desktop session loads.

You can therefore add a new file, such as env.sh inside the directory /etc/profile.d . In this file, we can export the PATH variable, setting it permanently to our choice of path directories, for example:

Files in /etc/profile.d are sourced by /etc/profile, thus activating our system-wide PATH whenever a user logs in.

We can also set PATH for all users in /etc/environment , which takes key-value pairs of the form:

Troubleshooting PATH Problems

As we saw, setting the PATH permanently in Linux has many options. You can set the PATH for only a certain user, for all users, or for only certain types of command shells. However, it’s a good idea to not fiddle with system-wide PATH settings unless you really know what you are doing.

If you encounter problems, a good starting point is to find out the current value of $PATH, by running the command:

For more troubleshooting tips, check out this resource.

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How can I change the PATH for all users and all shells?

I’m on a Linux Mint system and I use bash and zsh as shells. I’ve just manually installed Texlive and I want it to be in my path.

I thought adding the following lines to .profile would be fine, but zsh does not load .profile.

Obviously, everything that mentions «add it to .zshrc / .bashrc» cannot be correct, as this will only affect me (only one user) and only those two shells.

(I have administrative rights on my machine.)

3 Answers 3

ZSH reads /etc/zsh/zprofile. So change that file.

You can change /etc/profile & /etc/bash_bashrc , those apply for all users.

bash , ksh , dash , sh , and other shells related to sh all start by reading /etc/profile .

For zsh , I would recommend putting the change in /etc/zshenv . On the plus side, this file is guaranteed to be sourced, and sourced first, by any interactive zsh . On the minus side, it’s guaranteed :), so don’t put anything time-consuming here. Adding a few directories to PATH shouldn’t be time-consuming, though.

Any of the other zsh startup files may or may not be read, depending on the settings in the user’s private .zshenv file, which is the second file to be sourced.

For csh and its derivatives, /etc/csh.cshrc is probably the best bet.

For any shells I may have missed, you’ll have to consult their documentation.

For any shell, be sure to check the documentation on your system to verify the location of the shells’ files; they may be different depending on how the shell was compiled.

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Setting the PATH so it applies to all users, including root/sudo

The instructions in How do I set PATH variables for all users on a server? work to set the PATH for all ‘normal’ users. However, if I do sudo -s and then printenv PATH the updated path is not shown. I’ve taken a look at for example Setting TeX Live path for root, but this does not seem to make sense to me, perhaps as I’m from a Windows background. Is there any way to set the truly system-wide path, such that the entries are inherited by absolutely every process running on the system?

2 Answers 2

Update:

Setting global environment variables should still be performed in /etc/environment , but as you pointed out, using sudo -s has the effect of these variables are «vanished».

The reason for that is sudo has a policy of resetting the Environment and setting a secure path. It is enabled by default:

Thus whatever is set in the /etc/environment for the path is overridden by sudo .

The manual page for sudoers states:

As a workaround, you can use sudo su that will provide a shell with root privileges but containing the right PATH.

Original Answer

You should set it in /etc/environment .

Try sudo YOUR_TEXT_EDITOR /etc/environment (make sure to create a backup first).

System-wide environment variables

Environment variable settings that affect the system as a whole (rather then just a particular user) should not be placed in any of the many system-level scripts that get executed when the system or the desktop session are loaded, but into

/etc/environment — This file is specifically meant for system-wide environment variable settings. It is not a script file, but rather consists of assignment expressions, one per line. Specifically, this file stores the system-wide locale and path settings.

/etc/profile — This file gets executed whenever a bash login shell is entered (e.g. when logging in from the console or over ssh), as well as by the DisplayManager when the desktop session loads. This is probably the file you will get referred to when asking veteran UNIX system administrators about environment variables. In Ubuntu, however, this file does little more then invoke the /etc/bash.bashrc file.

/etc/bash.bashrc — This is the system-wide version of the

/.bashrc file. Ubuntu is configured by default to execute this file whenever a user enters a shell or the desktop environment.

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