If I try to run virtualenv, I get this message:
$ virtualenv
-bash: /Users/me/Library/Python/3.6/bin/virtualenv: No such file or directory
It's not surprising that this happens, because I've removed this directories at an earlier point when trying to clean up my computer from different Python versions. However, how does my system know to look in that directory for virtualenv? I've looked in my bash profile, and there is no mention of virtualenv there.
When you type something your command interpreter has to search the command. Of course it cannot try every possible directory on your system. Then it provides to the user a way to control that process. This is the purpose of the PATH environment variable :
$ echo $PATH
will show you the actual value which looks like dir1:dir2:...:dirn, meaning that commands where searched for in dir1, then dir2, etc. You have to remove the value /Users/me/Library/Python/3.6/bin/ from it. The best way is to edit the .bashrc or .bash_profile file to remove the permanent setting of this variable. Then reconnect.
Related
-bash: export: /Users/deboadebayo/Desktop/Coding/:/opt/anaconda3/bin:/Library/Frameworks/Python.framework/Versions/3.8/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin':
not a valid identifier
The above message is the error message I receive every time I open my terminal. I did create a backup of my bash profile. But essentially now I can no longer navigate anywhere I want to go using command line requests.
Any help would be much appreciated
If you have a backup, use an absolute path to the mv and cp commands to rename your broken file and restore the backup, both without depending on path lookup.
/bin/mv .bash_profile .bash_profile.broken
/bin/cp .bash_profile.backup .bash_profile
Close the current terminal window and open a new one, which should use your working, original .bash_profile to initialize PATH. Now you try to make the correct modification to your PATH.
oops. The easiest way to fix it would be to launch an editor with an absolute path. $PATH only specifies the locations in which the shell will search if told to execute a program relative (or no) path specified. The which program can search the path and shows the first executable found:
$ which vim
/usr/bin/vim
So if you're a vim user, you should be able to run /usr/bin/vim at the command line, and the path won't be relevant. Then you can fix your file in the editor. Looks like my osx machine also has nano if you'd prefer that editor. I don't think I installed it so it probably came shipped with osx I'm guessing:
$ which nano
/usr/bin/nano
If you want to revert to your backup, use cp, but specify it from its absolute position, /bin/cp:
$ /bin/cp first.txt second.txt
Obviously you'll want to change the file names on that one for it to work for you.
I am trying to execute a Makefile script and my Mac complains about 7zcat, although I already have 7z installed.
/bin/sh: 7zcat: command not found
Any thoughts on what's missing on my system? Thank you!
I have never used 7zcat before.
However, it looks like it needs to be installed on your system.
https://github.com/essentialkaos/7zcat
Also, after you download install 7zcat you have to give it execute permission with chmod. Finally, you have to execute it by calling its full path for example if you installed it to the directory you are in you would run ./7zcat file.7z or you would add the path to the file to your environment's $PATH variable.
I hope this helps. You might have to do some more research though.
When you open a Terminal window and type 7zcat and hit enter, what happens? Same message? Well, if you cannot use it, why should make be able to use it? Where and how have you installed 7z? Is the folder with the 7z binaries in your PATH? Since if it isn't, of course the command won't be found.
When the system shall run a command, it will search for this command in the directories stored in the PATH variable. Execute echo $PATH in terminal and you will get a colon separated list of directories; only these directories are searched for binaries. So either you must move your binaries to one of these (or put a symlink to one of these) or add the directory with these binaries to the PATH.
Yet there is no official 7z command line installer for MacOS, which brings me back to the original questions "Where and how have you installed 7z?" And are you sure that whatever you installed even includes a 7zcat?
I feel like I'm missing something very basic so apologies if this question is obtuse. I've been struggling with this problem for as long as I've been using the bash shell.
Say I have a structure like this:
├──bin
├──command (executable)
This will execute:
$ bin/command
then I symlink bin/command to the project root
$ ln -s bin/command c
like so
├──c (symlink to bin/command)
├──bin
├──command (executable)
I can't do the following (errors with -bash: c: command not found)
$ c
I must do?
$ ./c
What's going on here? — is it possible to execute a command from the current directory without preceding it with ./ and also without using a system wide alias? It would be very convenient for distributed executables and utility scripts to give them one letter folder specific shortcuts on a per project basis.
It's not a matter of bash not allowing execution from the current directory, but rather, you haven't added the current directory to your list of directories to execute from.
export PATH=".:$PATH"
$ c
$
This can be a security risk, however, because if the directory contains files which you don't trust or know where they came from, a file existing in the currently directory could be confused with a system command.
For example, say the current directory is called "foo" and your colleague asks you to go into "foo" and set the permissions of "bar" to 755. As root, you run "chmod foo 755"
You assume chmod really is chmod, but if there is a file named chmod in the current directory and your colleague put it there, chmod is really a program he wrote and you are running it as root. Perhaps "chmod" resets the root password on the box or something else dangerous.
Therefore, the standard is to limit command executions which don't specify a directory to a set of explicitly trusted directories.
Beware that the accepted answer introduces a serious vulnerability!
You might add the current directory to your PATH but not at the beginning of it. That would be a very risky setting.
There are still possible vulnerabilities when the current directory is at the end but far less so this is what I would suggest:
PATH="$PATH":.
Here, the current directory is only searched after every directory already present in the PATH is explored so the risk to have an existing command overloaded by an hostile one is no more present. There is still a risk for an uninstalled command or a typo to be exploited, but it is much lower. Just make sure the dot is always at the end of the PATH when you add new directories in it.
You could add . to your PATH. (See kamituel's answer for details)
Also there is ~/.local/bin for user specific binaries on many distros.
What you can do is add the current dir (.) to the $PATH:
export PATH=.:$PATH
But this can pose a security issue, so be aware of that. See this ServerFault answer on why it's not so good idea, especially for the root account.
I was trying to install Sencha Touch SDK tools 2.0.0 but could not run it properly. It created an entry in the $PATH variable.
Later I deleted the sencha sdk tools folder but didn't realize that the path variable is still there.
When i did echo $PATH I got -
/Applications/SenchaSDKTools-2.0.0-beta3:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin
I searched on how to remove variables from $PATH and followed these steps :
Gave the command PATH="/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin"
Did echo $PATH which showed /usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin
gave the command export PATH
Closed terminal and reopened it. Gave the command echo $PATH. This time I got
/Applications/SenchaSDKTools-2.0.0-beta3:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin
Can anyone tell me what am i doing wrong?
echo $PATH and copy it's value
export PATH=""
export PATH="/path/you/want/to/keep"
Check the following files:
/etc/bashrc
/etc/profile
~/.bashrc
~/.bash_profile
~/.profile
~/.MacOSX/environment.plist
Some of these files may not exist, but they're the most likely ones to contain $PATH definitions.
On MAC OS X Leopard and higher
cd /etc/paths.d
There may be a text file in the above directory that contains the path you are trying to remove.
vim textfile //check and see what is in it when you are done looking type :q
//:q just quits, no saves
If its the one you want to remove do this
rm textfile //remove it, delete it
Here is a link to a site that has more info on it, even though it illustrates 'adding' the path. However, you may gain some insight.
What you're doing is valid for the current session (limited to the terminal that you're working in). You need to persist those changes. Consider adding commands in steps 1-3 above to your ${HOME}/.bashrc.
If you're removing the path for Python 3 specifically, I found it in ~/.zprofile and ~/.zshrc.
$PATH contains data that is referenced from actual files. Ergo, you should find the file containing the reference you want to delete, and then delete said reference.
Here is a good list to run through progressively [copied from #Ansgar's answer with minor updates].
/etc/bashrc
/etc/profile
~/.bashrc
~/.bash_profile
~/.profile
~/.MacOSX/environment.plist
/etc/paths
/etc/paths.d/
Note that /etc/paths.d/ is a directory that contains files with path references. For example, inside this directory may be a file called, say, fancy-app, and inside this file you'll see an entry like below:
/path/to/fancy-app
This path will appear in your $PATH and you can delete the entry in the file to remove it, or you can delete the file if it has only the one reference you want to remove.
Use sudo pico /etc/paths inside the terminal window and change the entries to the one you want to remove, then open a new terminal session.
when you login, or start a bash shell, environment variables are loaded/configured according to .bashrc, or .bash_profile. Whatever export you are doing, it's valid only for current session. so export PATH=/Applications/SenchaSDKTools-2.0.0-beta3:$PATH this command is getting executed each time you are opening a shell, you can override it, but again that's for the current session only. edit the .bashrc file to suite your need. If it's saying permission denied, perhaps the file is write-protected, a link to some other file (many organisations keep a master .bashrc file and gives each user a link of it to their home dir, you can copy the file instead of link and the start adding content to it)
Close the terminal(End the current session). Open it again.
If the manual export $PATH method does not seem to be working after you close the terminal and open again, definitely check the shell configuration files.
I found a small script that kept adding some more path in front of the $PATH everytime it was open.
For zsh you can check the ~/.zshrc file.
I did try to find the answer online but unfortunately came up empty handed. Searching for './' in combination with other keywords brings up many hits, but none that helped...
Anyhow, as you can probably tell, I am rather new to MacOs. I am running mongo from the shell.
I cd into the /bin folder and start the mongo daemon with:
'./mongod'
.
If I just enter 'mongod', I get the following error:
'-bash: mongod: command not found'
What does the
'./'
in './mongod' stand for? Why is it needed? Why can't I just execute mongo by typing mongod. After all, I am in the correct directory.
After all, I am in the correct directory
But that directory isn't in the PATH. The gist of the matter is that when the shell wants to execute something it looks into a list of directories (specified in a variable called PATH). And the current directory isn't in that list.
As explained in the answer by cnicutar the shell tries to match the command you enter with executables in the directories that are listed in the PATH environment variable.
Although you could add the current directory to the PATH, it's probably not a good idea to do it. This article gives some good reasons why Linux doesn't add it by default:
Its a measure to plug possible security holes. You can't run commands
in the current directory without specifically calling them.
ie ./myscript.sh
To stop nasties writing a vicious shell script, placing the script in
an innocent location such as /tmp and getting root to run the script.
Would root run a nefarious script? If the script was named 'ls' and
root did a listing, the script would automatically run.