Messed up PATH environment variable in Ubuntu 16.04 [duplicate] - bash

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How to restore .bash_profile on a mac? None of my unix terminal are working [closed]
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I tried installing Anaconda to get many python packages at once but had some issues with python IDLE where it said No package found so had to manually set the path in ~/.bashrc.
Once I set the path in ~/.bashrc the IMPORT ERROR in python IDLE was solved but I'm unable to use commands on terminal now.
I'm getting this error all the time.
sid#sids-ubuntu:~$ ls
Command 'ls' is available in '/bin/ls'
The command could not be located because '/bin' is not included in the PATH environment variable.
ls: command not found
sid#sids-ubuntu:~$ sudo
Command 'sudo' is available in '/usr/bin/sudo'
The command could not be located because '/usr/bin' is not included in the PATH environment variable.
sudo: command not found
sid#sids-ubuntu:~$ mkdir aa
Command 'mkdir' is available in '/bin/mkdir'
The command could not be located because '/bin' is not included in the PATH environment variable.
mkdir: command not found
I did export PATH=/usr/bin:/bin to find out my $PATH and content of /etc/environment. It seems both are different.
sid#sids-ubuntu:~$ export PATH=/usr/bin:/bin
sid#sids-ubuntu:~$ echo $PATH
/usr/bin:/bin
sid#sids-ubuntu:~$ cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
Doesn't Ubuntu look for $PATH in /etc/environment?
If yes, what could be the reason my $PATH is different from /etc/environment? and please help me fix it!
If not, where does Ubuntu look for $PATH? please help me fix it!

Be aware that your /etc/environment is only re-read at reboot.
When you want to change your path, be sure to include the existing part as well. To do that, add $PATH in the new path definition.
export PATH="$PATH:/usr/bin"
Looking at your problems, adding the $PATH in your ~/.bashrc should do the trick. If not, open a new terminal and show us the output of
echo $PATH

When adding some directory to PATH it's good idea not to overwrite previous value, just append desired directory (e.g. $HOME/bin), in your ~/.bashrc add at the end line (and remove any previous tampering with PATH)
export PATH="$PATH:$HOME/bin"
and run:
source ~/.bashrc
(or just open new session of terminal).

PATH is an environment variable, and therefore it is not looked up in any file.
There are several files which are sourced when bash is invoked (see the section named INVOCATION in the bash man page), and while sourcing these files, the environment variable PATH can be set, respectively manipulated. Note that .bashrc is not always processed; please read the bash man-page carefully to understand, which files are included under which condition.

Related

How do programs add to $PATH variable with using .bash_profile?

How do some programs seem to add to the $PATH variable without using a .bash_profile file? What are the advantages to these approaches of adding to $PATH variable, but not using a .bash_profile file?
For my mac
echo $PATH returns
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin:/Library/Apple/usr/bin
which java returns
/usr/bin/java
which tex returns
/Library/TeX/texbin/tex
How is Java available in the terminal without being in the $PATH variable? (This is an example of something running in the terminal without being in the $PATH variable.)
How did TeX add to the PATH variable without using a .bash_profile file?
What added Library/Apple/usr/bin to the PATH variable? Wikipedia says that only the first three are defaults: /bin, /usr/bin, and /usr/local/bin.
Note: Other StackOverflow posts helped users create a .bash_profile file (a file that doesn't exist by default on a Mac) to run programs such as android and adb when they received -bash: android: command not found
My question is about how the terminal works (like how java is running without being on $PATH) and how other programs (like TeX) added to $PATH without using a file like .bash_profile.
I am running macOS 10.15.5, confirmed that I do not have a .bash_profile file, do have homebrew installed (not sure if that affects anything) and when I open a terminal, it says "The default interactive shell is now zsh." (I think I installed zsh after reading a different StackOverflow a few weeks back.

How to update PATH to find nvcc for CUDA 8.0? [duplicate]

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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

Terminal commands can not be found OSX

A majority of terminal commands don't work, for example .
ls
sudo
vi
with the error -bash: ls: command not found my path is echo $PATH
“/Users/username/usr/local/bin I get the feeling that “ should not be there but not sure how edit it.
What should the path be and how do I get the path to stay the same?
You need to add more paths to your $PATH variable. Try running whereis ls and check where is the binary of the command.
You can add more paths like this: export PATH=$PATH:NEW_PATH
I had a similar experience recently where a lot of my terminal commands were not being found despite being clearly saved in my bash_profile. After lengthy process of elimination I realised that the issue was caused when I tried to export a new path. The error that I had made was putting a space in the command. So I had to change
export SOMETHING = /path/to/something.apk to
export SOMETHING=/path/to/something.apk
So I would recommend you check all your path declarations to ensure you don't have any white spaces. Also don't forget to source your bash_profile or what ever type of command line shell you use.

Setting PATH environment variable in OSX permanently

I have read several answers on how to set environment variables on OSX permanently.
First, I tried this, How to permanently set $PATH on Linux/Unix but I had an error message saying no such file and directory, so I thought I could try ~/.bash_profile instead of ~/.profile but it did not work.
Second, I found this solution How to set the $PATH as used by applications in os x , which advises to make changes in
~/.MacOSX/environment.plist
but again I had no such file and directory error.
I need a way to set these variables such that it won't require setting them again and again each time I open a new terminal session.
You have to add it to /etc/paths.
Reference (which works for me) : Here
I've found that there are some files that may affect the $PATH variable in macOS (works for me, 10.11 El Capitan), listed below:
As the top voted answer said, vi /etc/paths, which is recommended from my point of view.
Also don't forget the /etc/paths.d directory, which contains files may affect the $PATH variable, set the git and mono-command path in my case. You can ls -l /etc/paths.d to list items and rm /etc/paths.d/path_you_dislike to remove items.
If you're using a "bash" environment (the default Terminal.app, for example), you should check out ~/.bash_profile or ~/.bashrc. There may be not that file yet, but these two files have effects on the $PATH.
If you're using a "zsh" environment (Oh-My-Zsh, for example), you should check out ~./zshrc instead of ~/.bash* thing.
And don't forget to restart all the terminal windows, then echo $PATH. The $PATH string will be PATH_SET_IN_3&4:PATH_SET_IN_1:PATH_SET_IN_2.
Noticed that the first two ways (/etc/paths and /etc/path.d) is in / directory which will affect all the accounts in your computer while the last two ways (~/.bash* or ~/.zsh*) is in ~/ directory (aka, /Users/yourusername/) which will only affect your account settings.
Read more: Mac OS X: Set / Change $PATH Variable - nixCraft
For a new path to be added to PATH environment variable in MacOS just create a new file under /etc/paths.d directory and add write path to be set in the file. Restart the terminal. You can check with echo $PATH at the prompt to confirm if the path was added to the environment variable.
For example: to add a new path /usr/local/sbin to the PATH variable:
cd /etc/paths.d
sudo vi newfile
Add the path to the newfile and save it.
Restart the terminal and type echo $PATH to confirm
You can open any of the following files:
/etc/profile
~/.bash_profile
~/.bash_login (if .bash_profile does not exist)
~/.profile (if .bash_login does not exist)
And add:
export PATH="$PATH:your/new/path/here"
You could also add this
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi
to ~/.bash_profile, then create ~/.bashrc where you can just add more paths to PATH. An example with .
export PATH=$PATH:.
If you are using zsh do the following.
Open .zshrc file nano $HOME/.zshrc
You will see the commented $PATH variable here
# If you come from bash you might have to change your $PATH.
# export PATH=$HOME/bin:/usr/local/...
Remove the comment symbol(#) and append your new path using a separator(:) like this.
export
PATH=$HOME/bin:/usr/local/bin:/Users/ebin/Documents/Softwares/mongoDB/bin:$PATH
Activate the change source $HOME/.zshrc
You're done !!!
sudo nano /etc/paths
now find the path of command i am giving an example of setting path for flutter.
/Users/username/development/flutter/bin
now cntrol+x and then y . reopen the terminal and check.
launchctl setenv environmentvariablename environmentvariablevalue
or
launchctl setenv environmentvariablename `command that will generate value`
use proper ` and remember to restart application or terminal for the environment variable to take effect.
you can check environment variable by printenv command.
note : environment variable named path is already set by someone else so we are not appending anything to that path at all here.
shows all hidden files like .bash_profile and .zshrc
$ ls -a
Starting with macOS Catalina, mac uses zsh instead of bash. so by default mac uses zsh.
Check which shell running:
$ echo $SHELL
/usr/zsh
$ cd $HOME
$ open -e .zshrc
or if using vim
$ vi .zshrc
Then add it like this
$ export my_var="/path/where/it/exists"
$ export PATH=$PATH:/$my_var/bin
For example: if installed app named: myapp in /Applications
Then
export MYAPP_HOME=/Applications/myapp
export PATH=$PATH:$MYAPP_HOME/bin
or shortcut
export PATH=${PATH}:/Applications/myapp/bin
TADA you set for life !!! Thank me later
19 October 2021.
Confirming iplus26's answer with one correction.
Test environment
OS: macOS 11.6 (Big Sur) x86_64
Shell: zsh 5.8
Below is the order in which the $PATH environment variable is modified:
each line in etc/paths text file gets appended
each line in each text file inside etc/paths.d directory gets appended
finally, the $PATH is further modified in ~/.zshrc
iplus26's answer stated "when (you run) echo $PATH, The $PATH string will be PATH_SET_IN_3&4:PATH_SET_IN_1:PATH_SET_IN_2" but this isn't always the case. It will have to depend on what the script is doing inside .zshrc. E.g. If we do something like
PATH="/new/path:${PATH}"
then, the new path will be in the beginning of the path list. However, if we do something like
PATH="${PATH}:/new/path"
then, the new path will be appended at the end of the path list.
Of course, you'll have to make sure you export the modified path in the ~/.zshrc file.
export PATH=$PATH
One handy command you could use to "pretty print" your path list is
print -l $path
This will print each path on a new line for better readability. Note $path is like $PATH except it's delimited by a single space, instead of a colon, :.
Hopefully this can further clarify for newcomers to this thread.
For setting up path in Mac two methods can be followed.
Creating a file for variable name and paste the path there under
/etc/paths.d and source the file to profile_bashrc.
Export path variable in ~/.profile_bashrc as
export VARIABLE_NAME = $(PATH_VALUE)
AND source the the path. Its simple and stable.
You can set any path variable by Mac terminal or in linux also.

Cygwin shell doesn't execute .bashrc

After start the cygwin shell, it just locate in a wrong home dir:
xfire#codingme.com ~
$ pwd
/cygdrive/c/Users/xfire
But it used to be /home/xfire
xfire#codingme.com /etc
$ cat passwd | grep xfire
xfire:unused:22773:10513:U-CORP\xfire,S-1-5-21-527237240-725345543-682003330-12773:/home/xfire:/bin/bash
And the .bashrc in the /home/xfire was not executed, even I copy it to the /cygdrive/c/Users/xfire, it also doesn't work!
On cygwin, I add this to my ~/.bash_profile:
. ~/.bashrc
Some program add an "HOME" environment in windows registry and set the value to "C:\Users\xfire", that's why cygwin take that directory as the home. cygwin.com/faq-nochunks.html
On my version of cygwin I found that only ~/.profile was being execueted so added
if [ -e "${HOME}/.bash_profile" ]; then
source "${HOME}/.bash_profile"
fi
to the .profile file. My .bash_profile file contains another test for .bashrc and executes that from inside there. I also added the following two lines to my .bashrc file.
export BASH_ENV="${HOME}/.profile"
export ENV="${HOME}/.profile"
The first of these ensures that .profile gets executed in non-interactive terminals and the second ensures it gets executed in POSIX terminals. I found a very useful explanation of what get run and when in the Bash Reference Manual.
In your case it wouldn't help as you have an issue with the value of your HOME environment variable but this page comes up quite high on the list when searching for this issue.
You can also also set BASH_ENV variable, e.g., BASH_ENV='C:\DOCUME~1\dwyttenb\.bashrc'
~/.bash_profile is executed before the initial command prompt is returned to the user. After that, every time a new shell is opened, ~/.bashrc is executed.
Adding . ~/.bashrc at end of ~/.bash_profile has resolved the problem.
Now you can check existing aliases using alias command.
Find more details on github.

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