I am trying to delete all files on the Desktop of seperate users from my admin account using a shell script.
This is my code to delete (for student)
sudo rm /Users/student/Desktop/*
but i get an error:
rm: /Users/student/Desktop/*: No such file or directory
When i run the script it prompts me for the Admin pass, then errors out.
Is using the Desktop/* appropriate? any tips? Thanks
The path expansion is done before sudo is executed. This means, it is done with the access rights of the current user and if you may not access /Users/student/Desktop then the expansion fails. Instead, do this:
sudo bash -c "rm /Users/student/Desktop/*"
This way the path expansion is done with the elevated rights granted by sudo. You might need to do rm -r if there are any directories/bundles on the desktop.
Related
I am running a bash script and these commands in the script will not work without sudo in front of them. The script.sh is located in a folder such as /jobs/script.sh
Example of commands I am trying to run in the script.sh -
mv /var/app/myapp /var/app/myapp.old
rm file.tar.gz
tar -xzf /home/ubuntu/file.tar.gz -C /var/app/
All the above work if I add sudo in front of them.
I am trying to figure out what permissions are required for them to work without adding sudo in the script.
I have tried giving the script.sh rwx permissions and changing owner to root.
I'm learning permissions in linux, so I'm new to this. Basically what permission should the script.sh have so that I dont have to use sudo in the bash file? Any insight would greatly help.
When you run sudo <some command>, then <some command> is run by the root user (Super user do). The reason you might need to run any command using sudo is because the permissions on the files that command reads/writes/executes are such that only the "Super user" (root) has that permission.
When executing the command mv fileA fileB, the executing user would need:
Write permission to fileB if fileB already existed
Write permission to the directory containing fileB
From what you said it’s most likely you want read and write permissions you can achieve this with chmod
Chmod +[permission] filename
(+ is used to add permission you can also use - instead to remove it)
Where permissions can be:
r —> read
w—> write
x —>excecute
... and more
FOR EXAMPLE: it seems you write permissions for the first file so :
chmod +w /var/app/myapp
Will fix problem
I've created a simple bash script that grabs some data and then outputs it to a log file. When I run the script without sudo it fails to write to the logs and says they are write-protected. It then ask me if it should unwrite-protect them, but this fails (permission denied).
If I run the script as sudo it appears to work without issue. How can I set these log file to be available to the script?
cd /home/pi/scripts/powermonitor/
python /home/pi/powermonitor/plugpower.py > plug.log
echo -e "$(sed '1d' /home/pi/scripts/powermonitor/plug.log)\n" > plug.log
sed 's/^.\{139\}//' plug.log > plug1.log
rm plug.log
grep -o -E '[0-9]+' plug1.log > plug.log
rm plug1.log
sed -n '1p' plug.log > plug1.log
rm plug.log
perl -pe '
I was being dumb. I just needed to set the write permissions on the log files.
The ability to write a file depends on the file permissions that have been assigned to that file or, if the file does not exist but you want to create a new file, then the permissions on the directory in which you want to write the file. If you use sudo, then you are temporarily becoming the root user, and the root user can read/write/execute any file at all without restriction.
If you run your script first using sudo and the script ends up creating a file, that file is probably going to be owned by the root user and will not be writable by your typical user. If you run your script without using sudo, then it's going to run under the username you used to connect to the machine and that user will need to have permission to write the log files.
You can change the ownership and permissions of directories and files by using the chown, chmod, chgrp commands. If you want to always run your script as sudo, then you don't have much to worry about. If you want to run these commands without sudo, that means you're running them as some other user and you will need to grant write permission to that user, whoever it is, in order to write the files/folders where the log files get written.
For instance, if I wanted to run the script as user sneakyimp and wanted the files written to /home/sneakyimp/logs/ then I'd need to make sure that directory was writable by sneakyimp:
sudo chown -R sneakyimp:sneakyimp /home/sneakyimp/logs
This command changes ownership of that directory and its contents to the user sneakyimp. You might also need to run some chmod commands to make sure they are writable by owner.
I have a user named cam. Cam stores a bunch of files. Now I want to move those files so I tried the following...
sudo mv /home/cam/DCS-*.jpg /home/cam/cam/
But when I run this command I get...
mv: cannot stat ‘/home/cam/DCS-*.jpg’: No such file or directory
But if I runt the command like...
sudo mv /home/cam/DCS-934L2015110711425501.jpg /home/cam/cam/
It works fine. WTF am I missing
if I do a sudo ls /home/cam I see everything but without sudo I don't have permissions to see anything.
When this command is executed:
sudo mv /home/cam/DCS-*.jpg /home/cam/cam/
The * is expanded by the shell according to the permissions of the current user. As the current user cannot see those files (ls /home/cam has no permission), the shell cannot expand the parameter list.
shouldn't sudo have permissions regardless?
No. With sudo, the mv command will be executed as root, but the parameter list expansion happens before execution is passed to sudo mv.
To have the * expansion happen with root permission (so that the content of the directory will be visible), you can wrap the command in its own shell like this:
sudo sh -c 'mv /home/cam/DCS-*.jpg /home/cam/cam/'
Hi I made a script as root called whatever and saved it in /
I then made a new user adduser guest
when i log in as guest via su - guest and try to run the script with cd / && ./whatever
I get permission denied which is good, but all i have to do is bash /whatever and it works.
Is the correct sollution to chmod /bin/bash? No
If you want to allow a user to run a shell script, you have to give them both "execute" and "read" permissions on the file.
If you want to prevent a user from running a shell script, you have to remove the "read" permission. Even if the file is marked as executable, the user can not execute a non-readable script.
There is no way to allow a user to execute but not read a shell script.
Similarly, there is no way to allow a user to read but not to execute a shell script.
No!
Never touch the permissions on anything in /bin. You need to change the permissions on ./whatever. You'll need to add execute permissions to it - chmod u+x ./whatever. If you want it to run.
If however, you want to stop someone running it... well, you have to set it unreadable. Because there's no difference between a script you can read and a script you can 'run'. They're just sequences of commands.
I want to have my AppleScript application run a Python script with sudo, but I don't want the application to prompt the user for a password (our users do not have sudo privileges).
The Python script has been added to the /etc/sudoers file appropriately (ALL ALL=NOPASSWD: /path/to/script.py). In the terminal, I can do (as a regular, non-privileged user):
$ sudo ./script.py
and it runs perfectly well. But in AppleScript when you try to do:
do shell script "sudo ./script.py"
You of course get the "sudo: no tty present and no askpass program specified" error. But if you change it to:
do shell script "./script.py" with administrator privileges
AppleScript insists on presenting a popup window to ask for the password. I have also tried passing a null password to sudo with a pipe:
do shell script "echo '' | sudo -S ./script.py"
but that also does not work. (I think it tries to run sudo individually first and then pass the command through, which won't work because the user doesn't have sudo privileges!)
I need a solution where AppleScript will run the Python script with sudo. I would prefer the script stays unreadable and un-executable by average users for security reasons, and is only executed through the AppleScript. (I know that, hypothetically, the users could call sudo script.py and it would run, but that's assuming they even know about sudoers; I'm trying to keep it as secure as possible while still usable).
I'm still pretty new to AppleScript, so any help would be greatly appreciated! Thanks!
When I added ALL ALL=NOPASSWD: /Users/myusername/a to sudoers and ran echo $'#!/bin/bash\nsay $(ls ~root|head -n1)'>~/a;chmod +x ~/a, do shell script "sudo ~/a" ran the script as root without requiring a password.
I'm guessing the problem is that you specified the path like do shell script "sudo ./script.py". Try to use do shell script "sudo ~/script.py" instead. The default working directory is for do shell script is / and not ~/.