I am using a boot script from a network vendor, I am using this on RedHat 7.2 The start script sets up the environment with several variables, however I don't think these variables are set-up correctly.
I have added the start-up script to /etc/environment and I can see that the variables are defined and available to all users.
This is an example of how the variables are defined in the script:
export V1=/opt/nameofsupplier/sdk/CentOS-RHEL-7-x86_64
export V2=${V1}/lib/cam
There are many more, if I try this from a terminal:
cd $V1
It works fine, however if I try:
cd $V2
I get:
base: cd $V1/lib/cam: No such file or directory
The path is valid, and if I do this in the shell:
export V2=${V1}/lib/cam
cd $V2
It works without any error, how do I fix the script?
You may be right in suspecting an ill-definition of these variables.
/etc/environment can only contain variable definitions - it is not executed like a normal script (see its documentation here, which says Variable expansion does not work in /etc/environment.), so no variable expansion of V1 in the definition of V2 takes place. Therefore V2 is not correctly defined.
Try to source /etc/environment lines in the system-wide /etc/profile (or its equivalent, depending on the shells of your users) or in specific users' ~/.profiles.As the last resort you can just plain copy the respective lines of /etc/environment to the above mentioned scripts (but this will make it harder to maintain).
You could also correct the definitions in /etc/environment not to rely on expansion, i.e. like this:
export V2=/opt/nameofsupplier/sdk/CentOS-RHEL-7-x86_64/lib/cam
(assuming there are not too much of them to be corrected). But this will also be hard to maintain.
I know I can just type
$ vi .bashrc
export JAVA_HOME=/usr/lib/jvm/java-7-oracle
export PATH=$JAVA_HOME/bin:$PATH
However how to use shell script to do it? I prefer to write shell script because I need to configure multiple servers, if type one by one I would take me a long time to go.
Can someone guide me how to do this? Thanks a lot!
EDIT: I just realized that you wanted a script to automate the process of adding environment variables. These commands may work for you:
echo "export JAVA_HOME=/usr/lib/jvm/java-7-oracle" >>~/.bashrc
echo "export PATH=$JAVA_HOME/bin:$PATH" >>~/.bashrc
What this does is append the given text to .bashrc. Instead of copying .bashrc files from server to server, run these commands (you could probably write a script for these) on each server. This preserves the contents of the original rc files on each server, which I find is a better idea than completely overwriting the file.
Original answer
Your .bashrc file is actually written as a shell script. You would place the exact same lines in the shell script, possibly with a hashbang at the beginning of the file. For example:
#!/bin/bash
export JAVA_HOME=/usr/lib/jvm/java-7-oracle
export PATH=$JAVA_HOME/bin:$PATH
# do java stuff here...
If you were to "do java stuff" in this script, this would work fine. However, if these variables are going to be used outside of the script, you would have to "source" this file. That is what happens with .bashrc. Before the first prompt is given, Bash runs source ~/.bashrc to publish the variables defined in .bashrc.
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On Linux, how can I add a directory to the $PATH so it remains persistent across different sessions?
Background
I'm trying to add a directory to my path so it will always be in my Linux path. I've tried:
export PATH=$PATH:/path/to/dir
This works, however each time I exit the terminal and start a new terminal instance, this path is lost, and I need to run the export command again.
How can I do it so this will be set permanently?
You need to add it to your ~/.profile or ~/.bashrc file.
export PATH="$PATH:/path/to/dir"
Depending on what you're doing, you also may want to symlink to binaries:
cd /usr/bin
sudo ln -s /path/to/binary binary-name
Note that this will not automatically update your path for the remainder of the session. To do this, you should run:
source ~/.profile
or
source ~/.bashrc
There are multiple ways to do it. The actual solution depends on the purpose.
The variable values are usually stored in either a list of assignments or a shell script that is run at the start of the system or user session. In case of the shell script you must use a specific shell syntax and export or set commands.
System wide
/etc/environment List of unique assignments. Allows references. Perfect for adding system-wide directories like /usr/local/something/bin to PATH variable or defining JAVA_HOME. Used by PAM and systemd.
/etc/environment.d/*.conf List of unique assignments. Allows references. Perfect for adding system-wide directories like /usr/local/something/bin to PATH variable or defining JAVA_HOME. The configuration can be split into multiple files, usually one per each tool (Java, Go, and Node.js). Used by systemd that by design do not pass those values to user login shells.
/etc/xprofile Shell script executed while starting X Window System session. This is run for every user that logs into X Window System. It is a good choice for PATH entries that are valid for every user like /usr/local/something/bin. The file is included by other script so use POSIX shell syntax not the syntax of your user shell.
/etc/profile and /etc/profile.d/* Shell script. This is a good choice for shell-only systems. Those files are read only by shells in login mode.
/etc/<shell>.<shell>rc. Shell script. This is a poor choice because it is single shell specific. Used in non-login mode.
User session
~/.pam_environment. List of unique assignments, no references allowed. Loaded by PAM at the start of every user session irrelevant if it is an X Window System session or shell. You cannot reference other variables including HOME or PATH so it has limited use. Used by PAM.
~/.xprofile Shell script. This is executed when the user logs into X Window System system. The variables defined here are visible to every X application. Perfect choice for extending PATH with values such as ~/bin or ~/go/bin or defining user specific GOPATH or NPM_HOME. The file is included by other script so use POSIX shell syntax not the syntax of your user shell. Your graphical text editor or IDE started by shortcut will see those values.
~/.profile, ~/.<shell>_profile, ~/.<shell>_login Shell script. It will be visible only for programs started from terminal or terminal emulator. It is a good choice for shell-only systems. Used by shells in login mode.
~/.<shell>rc. Shell script. This is a poor choice because it is single shell specific. Used by shells in non-login mode.
Notes
GNOME on Wayland starts a user login shell to get the environment. It effectively uses the login shell configurations ~/.profile, ~/.<shell>_profile, ~/.<shell>_login files.
Man pages
environment
environment.d https://linux.die.net/man/1/environment.d
bash
dash
Distribution-specific documentation
Ubuntu
Arch Linux
Related
Difference between Login Shell and Non-Login Shell?
In Ubuntu, edit /etc/environment. Its sole purpose is to store environment variables. Originally the $PATH variable is defined here.
This is a paste from my /etc/environment file:
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
So you can just open up this file as root and add whatever you want.
For immediate results,
Run (try as normal user and root):
source /etc/environment && export PATH
If you use Z shell (zsh), add this line right after the comments in /etc/zsh/zshenv file:
source /etc/environment
I encountered this little quirk on Ubuntu 15.10 (Wily Werewolf), but if your zsh is not getting the correct PATH, this could be why.
For Bash, you can put the export declaration in ~/.bashrc. For example, my .bashrc contains this line:
export PATH=/var/lib/gems/1.8/bin:/home/ash/.bin:$PATH
You may set $PATH permanently in two ways.
To set the path for a particular user:
You may need to make the entry in file .bash_profile in the home directory for the user.
E.g, in my case I will set the java path in the Tomcat user profile*
echo "export PATH=$PATH:/path/to/dir" >> /home/tomcat/.bash_profile
To set a common path for all system users, you may need to set the path like this:
echo "export PATH=$PATH:/path/to/dir" >> /etc/profile
You can use on CentOS or Red Hat Linux (RHEL) for the local user:
echo $"export PATH=\$PATH:$(pwd)" >> ~/.bash_profile
This adds the current directory (or you can use another directory) to the PATH. This makes it permanent, but it takes effect at the next user logon.
If you don't want do a re-logon, then you can use:
source ~/.bash_profile
That reloads the # User specific environment and startup programs. This comment is present in file .bash_profile.
You can also set it permanently, editing one of these files:
/etc/profile (for all users)
~/.bash_profile (for current user)
~/.bash_login (for current user)
~/.profile (for current user)
You can also use /etc/environment to set a permanent PATH environment variable, but it does not support variable expansion.
Extracted from: Linux: Añadir ruta al PATH
I think the most elegant way is:
Add this in the ~/.bashrc file.
Run this command:
gedit ~/.bashrc
Add your path inside it:
export PATH=$PATH:/opt/node/bin
source ~/.bashrc
(Ubuntu)
Modify the "/etc/profile" file:
vi /etc/profile
Press the I key to enter editing mode and move the cursor to the end of the file. Additional entries：
export PATH=$PATH:/path/to/dir;
Press the Esc key to exit edit mode, and :wq to save the file.
Make the configuration effective
source /etc/profile
Explanation：
The profile file works for all users. If you want it to be valid only for the active user, change the ".bashrc" file.
I stumbled across this question yesterday when searching for a way to add a folder containing my own scripts to the PATH - and was surprised to find out that my own ~/.profile file (on Linux Mint 18.1) already contained this:
# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
PATH="$HOME/bin:$PATH"
fi
Thus, all I had to do was create the folder ~/bin and put my scripts there.
You can add that line to your console configuration files (e.g., .bashrc, or to .profile).
After so much research, I found a simple solution for this (I am using Elementary OS), inspired by Flutter – Step by Step Installation on Linux – Ubuntu.
Run the following command to open the .bashrc file in edit mode. (You
may also use vi or any other editor).
~$ sudo nano ~/.bashrc
Add the following line at the end of the file and save.
export PATH="[FLUTTER_SDK_PATH]/flutter/bin:$PATH"
For example:
export PATH="/home/rageshl/dev/flutter/bin:$PATH"
I believe this is the permanent solution for setting the path in Flutter in a Ubuntu distribution.
It can be directly added by using the following command:
echo 'export PATH=$PATH:/new/directory' >> ~/.zshrc
source ~/.zshrc
One way to add a permanent path, which worked for me, is:
cd /etc/profile.d
touch custom.sh
vi custom.sh
export PATH=$PATH:/path according to your setting/
Restart your computer and here we go; the path will be there permanently.
Add script file [name_of_script].sh to the /etc/profile.d folder with the line:
export PATH=$PATH:/dir
Every script within the /etc/profile.d folder is automatically executed by /etc/profile on login.
My answer is in reference to the setting up of a Go environment on Ubuntu Linux (amd64). I have faced the same trouble of setting the path of environment variables (GOPATH and GOBIN), losing it on terminal exit and rebuilding it using the source <file_name> every time.
The mistake was to put the path (GOPATH and GOBIN) in ~/.bash_profile file. After wasting a few good hours, I found that the solution was to put GOPATH and GOBIN in the ~/.bash_rc file in the manner:
export GOPATH=$HOME/go
export GOBIN=$GOPATH/bin
export PATH=$PATH:$GOPATH:$GOBIN
And in doing so, the Go installation worked fine and there were no path losses.
The reason with which this issue can be related is that settings for non-login shells, like your Ubuntu terminal or GNOME terminal where we run the Go code, are taken from the ~./bash_rc file and the settings for login shells are taken from ~/.bash_profile file. And from the ~/.profile file if the ~/.bash_profile file is unreachable.
The files where you add the export command depends on if you are in login-mode or non-login-mode.
If you are in login-mode, the files you are looking for are either /etc/bash or /etc/bash.bashrc.
If you are in non-login-mode, you are looking for the file /.profile or for the files within the directory /.profiles.d
The files mentioned above is where the system variables are.
Permanently add to the PATH variable
Global:
echo "export PATH=$PATH:/new/path/variable" >> /etc/profile
Local (for the current user only):
echo "export PATH=$PATH:/new/path/variable" >> ~/.profile
For global, restart. For local, relogin.
Example
Before:
$ cat /etc/profile
#!/bin/sh
export PATH=/usr/bin:/usr/sbin:/bin:/sbin
After:
$ cat /etc/profile
#!/bin/sh
export PATH=/usr/bin:/usr/sbin:/bin:/sbin
export PATH=/usr/bin:/usr/sbin:/bin:/sbin:/new/path/variable
Alternatively you can just edit file "profile":
$ cat /etc/profile
#!/bin/sh
export PATH=/usr/bin:/usr/sbin:/bin:/sbin:/new/path/variable
Another way (thanks gniourf_gniourf):
echo 'PATH=$PATH:/new/path/variable' >> /etc/profile
You shouldn't use double quotes here! echo 'export
PATH=$PATH:/new/path/variable'... And by the way, the export keyword
is very likely useless as the PATH variable is very likely already
marked as exported. – gniourf_gniourf
Zues77 has the right idea. The OP didn't say "How can I hack my way through this?". The OP wanted to know how to permanently append to $PATH:
sudo nano /etc/profile
This is where it is set for everything and is the best place to change it for all things needing $PATH.
Let's say you're running macOS. You have a binary you trust and would like to make available across your system, but don't necessarily want the directory in which the binary is to be added to your PATH.
You can opt to copy/move the binary to /usr/local/bin, which should already be in your PATH. This will make the binary executable like any other binary you may already have access to in your terminal.
The simplest way is the following line,
PATH="<directory you want to include>:$PATH"
in your .bashrc file in the home directory.
It will not get reset even if you close the terminal or reboot your PC. It's permanent.
This is a one-liner. It adds a line to the .bashrc. That line is going to check if the directory has already been added to the path and append if not. This will prevent duplicating your directory in the path every time you source .bashrc.
echo "[[ \":\$PATH:\" != *\":$(pwd)/path/to/add:\"* ]] && export PATH=\"\${PATH:+\${PATH}}:$(pwd)/path/to/add\"" >> ~/.bashrc
source ~/.bashrc
I think the most elegant way is:
Add this in the ~./bashrc file:
if [ -d "new-path" ]; then
PATH=$PATH:new-path
fi
source *~/.bashrc*
(Ubuntu)
For a Debian distribution, you have to:
edit file ~/.bashrc. E.g: vim ~/.bashrc
add export PATH=$PATH:/path/to/dir
then restart your computer. Be aware that if you edit file ~/.bashrc as root, your environment variable you added will work only for root
I have added entries such as the following in my /etc/bashrc (on Fedora).
#=========== Maven Related variables
export JAVA_HOME='/usr/java/default'
export PATH=${JAVA_HOME}:$PATH
#=========== Maven Related variables
export M2_HOME=/usr/local/apache-maven/apache-maven-3.0.4
export PATH=${M2_HOME}/bin:$PATH
#=========== Ant Related variables
export ANT_HOME=/usr/local/apache-ant
export Path=${ANT_HOME}/bin:$PATH
Now, each time that I execute bash command to refresh the environment variables, all these additions are repeated, and the PATH just keep adding itself recursively; if I keep doing bash for a few dozen times, then the $PATH becomes a hundred lines of repeating content. What am I doing wrong?
Note that I have added these entries to /etc/bashrc since I want to have these values in PATH no matter what user I login as.
Thanks,
Shannon
Don't set your PATH incrementally in .bashrc; set it once in .profile and leave it alone thereafter. Or, since you mention /etc/bashrc, don't set the PATH incrementally in /etc/bashrc; set it once in /etc/profile and leave it alone.
One side-benefit; things will work a little faster.
See also the code in How do I manipulate PATH elements in shell scripts for code to clean up a repetitive PATH.
If by this statement:
... execute bash command to refresh the environment variables ...
you mean that you are entering the command
bash
at the command prompt, you are not "refreshing the environment variables". You are launching a new subshell of the current shell. The new shell inherits the path of the original shell, to which you are once again making additions. Each time you do this the PATH will get longer.
You can use something like:
PATH=$(echo "$PATH" | awk -v RS=: -v ORS=: '!(a[$0]++)' | sed 's/:$//')
to clean up your path after changing it. Also, since the the first match is used when scanning the path, having duplicates doesn't really matter.
I had also faced the same problem (CentOS). This is how I fixed it.
Added the following lines to my user's .profile
export PATH=/usr/local/apache-maven-3.3.3/bin:$PATH
export JAVA_HOME=/usr
export SHELL=/bin/bash
# to run bash (because ksh was my default shell)
/bin/bash
No changes to my user's .bashrc file
No changes to /etc/profile
No changes to /etc/bashrc
I'm using zsh terminal, and I'm trying to add a new entry (/home/david/pear/bin) to the PATH variable. I don't see a reference to the PATH variable in my ~/.zshrc file, but doing echo $PATH returns:
/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
So I know that the path variable is being set somewhere. Where is the PATH variable set / modified for the zsh terminal?
Actually, using ZSH allows you to use special mapping of environment variables. So you can simply do:
# append
path+=('/home/david/pear/bin')
# or prepend
path=('/home/david/pear/bin' $path)
# export to sub-processes (make it inherited by child processes)
export PATH
For me that's a very neat feature which can be propagated to other variables.
Example:
typeset -T LD_LIBRARY_PATH ld_library_path :
Here, add this line to .zshrc:
export PATH=/home/david/pear/bin:$PATH
EDIT: This does work, but ony's answer above is better, as it takes advantage of the structured interface ZSH provides for variables like $PATH. This approach is standard for bash, but as far as I know, there is no reason to use it when ZSH provides better alternatives.
You can append to your PATH in a minimal fashion. No need for
parentheses unless you're appending more than one element. It also
usually doesn't need quotes. So the simple, short way to append is:
path+=/some/new/bin/dir
This lower-case syntax is using path as an array, yet also
affects its upper-case partner equivalent, PATH (to which it is
"bound" via typeset).
(Notice that no : is needed/wanted as a separator.)
Common interactive usage
Then the common pattern for testing a new script/executable becomes:
path+=$PWD/.
# or
path+=$PWD/bin
Common config usage
You can sprinkle path settings around your .zshrc (as above) and it will naturally lead to the earlier listed settings taking precedence (though you may occasionally still want to use the "prepend" form path=(/some/new/bin/dir $path)).
Related tidbits
Treating path this way (as an array) also means: no need to do a
rehash to get the newly pathed commands to be found.
Also take a look at vared path as a dynamic way to edit path
(and other things).
You may only be interested in path for this question, but since
we're talking about exports and arrays, note that
arrays generally cannot be exported.
You can even prevent PATH from taking on duplicate entries
(refer to
this
and this):
typeset -U path
PATH pre-populated
The reason your path already has some entries in it is due to your system shell files setting path for you. This is covered in a couple other posts:
Why and where the $PATH env variable is set?
Where is the source of $PATH? I cannot find it in .zshrc
one liner, without opening ~/.zshrc file
echo -n 'export PATH=~/bin:$PATH' >> ~/.zshrc
or
echo -n 'export PATH=$HOME/bin:$PATH' >> ~/.zshrc
To see the effect, do source ~/.zshrc in the same tab or open a new tab
Added path to ~/.zshrc
sudo vi ~/.zshrc
add new path
export PATH="$PATH:[NEW_DIRECTORY]/bin"
Update ~/.zshrc
Save ~/.zshrc
source ~/.zshrc
Check PATH
echo $PATH
OPTION 1: Add this line to ~/.zshrc:
export "PATH=$HOME/pear/bin:$PATH"
After that you need to run source ~/.zshrc in order your changes to take affect OR close this window and open a new one
OPTION 2: execute it inside the terminal console to add this path only to the current terminal window session. When you close the window/session, it will be lost.
If you are on macOS (I'm on Monterey 12.3.1), you may have been pulling your hair like I did metaphorically. These instructions above all worked for me within the terminal session, but I could never get it to persist no matter what I did with export. Moreover, I couldn't find the .zshrc anywhere.
Turns out Apple does it differently. The file you need to edit is etc/paths. You can simply sudo nano /etc/paths and add your path in a new line. Then simply restart terminal and voila.
for me PATH=$PATH:/path/to/file/bin
then export PATH worked.
to check echo $PATH . other solutions are adding the path temporarily.
I'm on Monterey 12.4 and the only way I could change the path was using the helper function. Editing text files in nano did diddly squat
# append
path+=('/foo/bar/yourpath')
# export to sub-processes
export PATH
to verify your new directory has been added correctly, you can use
print -l $path
thanks to the fact that its type is known to be an array