I am new to Ubuntu. I need to set path in my .bashrc file, but I am getting permission denied error even if am the admin of the system .
export TCFRAME_HOME=~/tcframe
alias tcframe=$TCFRAME_HOME/scripts/tcframe
Now when I type tcframe version I get
bash: /home/p46562/tcframe/scripts/tcframe: No such file or directory
How to fix this?
The error message is telling you that you are trying to execute a file which does not exist.
We can vaguely guess about what files do exist, but without access to your system, we can't know for sure what you have actually installed and where.
Perhaps you have a file named tcframe in a directory called scripts in your home directory?
alias tcframe=$HOME/scripts/tcframe
A common arrangement to avoid littering your environment with one or more aliases for each random utility you have installed somewhere is to create a dedicated directory for your PATH - a common convention is to call it bin - and populate it with symlinks to things you want to have executable.
Just once,
mkdir $HOME/bin
and edit your .profile (or .bash_profile or .bashrc if you prefer) to include the line
PATH=$HOME/bin:$PATH
From now on, to make an executable script accessible from anywhere without an explicit path, create a symlink to it in bin;
ln -s $HOME/scripts/tcframe $HOME/bin
Notice that the syntax is like cp; the last argument is the destination (which can be a directory, or a new file name) and the first (and any subsequent arguments before the last, if the last is a directory) are the sources. When the destination is a directory, the file name of each source argument is used as the name of a new symlink within the destination directory.
Also notice that you generally want to use absolute paths; a relative path is resolved relative to bin (so e.g.
ln -s ../scripts/tcframe $HOME/bin
even if you are currently in a directory where ../scripts does not exist.)
Scripts, by definition, need to be executable. If they aren't, you get "permission denied" when you try to run them. This is controlled by permissions; each file has a set of permission bits which indicate whether you can read, write to (or overwrite), and execute this file. These permissions are also set separately for members of your group (so you can manage a crude form of team access) and everyone else. But for your personal scripts, you only really care that the x (executable) bit is set for yourself. If it isn't, you can change it - this is only required once.
chmod +x scripts/tcframe
Related
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.
Im having trouble in Bash.
I have plain files in a directory on my desktop. I am trying to move them into a subdirectory within that directory using: mv "Filename" /"Directoryname"
However when I use this command, I get an error telling me that the permission was denied.
I am set as the owner of both directories and have should have full permissions. If there is anything I need to provide you to make it easier for you to help me, I will be glad to help.
Try mv filename subDirectoryName/.
By placing / in front of the directory name in a move sequence, you're telling the shell that you would like it to be placed in a high level folder named /folder.
What you want is a sub-directory within your current directory. As you would usually move directories in bash, ../ goes up one directory, and directory/ implies you are moving into a folder that is within your current directory.
I have a command which is not working if I log-in to Unix using my ID.
$ db2licm -l
-bash: db2licm: command not found
But if the root gives the same command in the format ./db2licm -l, he gets valid results.
How can root publish the command so that it can be used by me also?
The ./ at the beginning of root's version of the command indicates that it is in the current directory (presumably root's home directory). To make it accessible to other users it should be moved or copied to a directory that is in their executable search path, such as /usr/bin, and its permission bits should be set so that anyone can execute it (normally mode 0755).
Usually that sort of thing should be done via the program's installer, not manually.
Your question doesn't have a single answer, because this depends on a lot of factor.
Access
First of all, in order to run a program from your account, you need to have execution privilege on the executable. You can check that you indeed have execution rights using ls -l :
$ ls -l /bin/bash
-rwxr-xr-x 1 root root 934336 2014-09-27 04:01 /bin/bash
Here, the characters rwxr-xr-x are respectively for user (root), group (root) and others access (three characters/flags for each). In my case, anybody can execute /bin/bash because the x flag is set on the last three character block (rwxr-xr-x).
Finding the executable
Secondly, the system needs to be able to find the executable. In your example, you specify that root launches the executable by prepending ./ before the command name, which basically mean "execute this program located in the current directory". Navigate anywhere else in your filesystem's tree structure and the command won't execute anymore.
To execute a command without specifying its exact path, this command must be in a directory included in your PATH environment variable. You can either add your command's directory to your PATH variable, move that command into a directory already present in your PATH variable (like /usr/bin) or create a symbolic link into a directory already present in your PATH variable, pointing to your command in its current directory.
Adding to PATH
If you'd like to add your executable's directory to your PATH environment variable on a permanent basis, you only need to modify your profile (usually ~/.bashrc if you are using bash or ~/.profile) by adding the following line :
export PATH="/the/directory/to/add:$PATH"
Note the : between your path and the $PATH variable.
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 am on Mac's OS 10.6, and I am trying to learn a thing or two about shell scripting. I understand how to save a shell script and make it executable, but I am wondering what I can do or where I can save the file to make it global (that is, accessible no matter what folder I am in).
For example, if I save a .sh file in the /Users/username/ directory and make it executable, I can only execute that script in that specific directory. If I navigate to /Users/username/Downloads, for example, I can't execute the script.
Also, any suggestions of resources for learning more about shell scripting would be helpful. Thanks
/usr/local/bin would be the most appropriate location. Mac OS X has it in the PATH by default
There are two ways to do it -
Put your script in usr/local/bin and make sure it is executable(chmod +x my_script)(This is already set in the path, you can check by doing an echo $PATH)
Create a folder in your home directory called bin. (For your personal scripts)
cd ~ (Takes you to your home directory)
mkdir bin (create a bin folder)
vim .bash_profile (to set path environment variable)
export PATH=~/bin:$PATH (Press i then add this line and then do esc and type :wq)
Now you can just type the name of your script and run it from anywhere you want.
** NOTE: If you want to run the script with a shortened command rather than typing your entire filename, add the following to your .bash_profile:
alias myscript='my_script.sh'
Then you can run the script by simply typing myscript. (you can sub in whatever alias you'd like)
Traditionally, such scripts either go in ~/bin (ie: the bin directory in your home directory) or /usr/local/bin/ The former means the script will only work for you, the latter is for scripts you want anybody on the system to be able to run.
If you put it in ~/bin, you may need to add that to your PATH environment variable. /usr/local/bin should already be on the path.
In mac operating system
Open bash ~/.bashrc file.
add path of your script in your bashrc file , using
export PATH="$PATH:/Users/sher.mohammad/Office/practice/practiceShell"
Open your ~./bash_profile file and add [[ -s ~/.bashrc ]] && source ~/.bashrc
open new terminal window
Now whenever you will open your terminal your script will be loaded
This one is super easy if you are familiar with your bashrc file! This will entirely use just your .bashrc file and takes 2 seconds to accomplish.
(I use Arch Linux Manjaro so I use .bashrc located in my home directory)
The code to be placed in your .bashrc file:
# Simple bashrc method to launch anything in terminal from any directory
YOURCOMMAND () {
cd /path/to/directory/containing/your/script/ && ./YOURSCRIPT
}
As you can see, first you use the simple 'cd' command and give it the directory of the scripts location, then use '&&' so that you can make the next command executed right after, and finally open your script just as you would normally! Super easy and saved right in your .bash file! :)
Hope I've helped someone!
Sincerely,
AnonymousX
On using bash shell, write that script as function and then put it to the .bashrc or source the file which containing that function by "source file_name"
Now execute the script by function call in the shell.
Either saving it in /usr/bin (or any other directory present in PATH) or editing PATH to include the directory you saved it in will basically make it run in any directory.
from the working directory of 'script.sh'" mv [script.sh] /usr/local/bin"( not tested but seems to be the least complex way IMO.)
You should put it in the global executable directory on your machine. I think that would usually be /usr/bin on Unix-based operating systems (this would however most often require super user privileges on that machine).
You could also put it in any other directory that is in the $PATH environment variable, although it would only work for those users who have that directory in that variable.
You can find the value of $PATH by typing echo $PATH in a shell. The directories are separated by :.