Editing .desktop file to run executable as root? - c

I have compiled a c program into an executable that I would now like to integrate into the applications menu in Debian 7.4 XFCE. In order to run the application under normal circumstances, I am required to type
sudo myprogram
Now I have created my .desktop file and placed it in /usr/share/applications
[Desktop Entry]
Type=Application
Encoding=UTF-8
Name=myprogram
Comment=configuration loader
Exec=sudo loader
Icon=/usr/share/icons/hicolor/48x48/apps/myprogram.png
Terminal=false
Categories=Development;IDE
The item is added to my applications menu as expected, and the icon shows up properly. The problem, however, is that double clicking the menu item to launch the application does nothing.
If I navigate to /usr/bin (where I have placed my executable) and type "sudo myprogram", the program launches as expected.
What can I do to fix this issue and get the program to launch from the menu? Perhaps /usr/bin is not the correct place to put it, or I have the incorrect Exec command. I greatly appreciate the help.

I ended up using (after installing gksu)
Exec = gksu myprogram
this launches a graphical sudo prompt, which is sufficient for my needs.

This is what the setuid bit in the permissions is for. It makes executables run with permissions of the file owner. This only works on actual executables, not on shell scripts!
sudo chmod u+s myprogram
sudo chown root myprogram
./myprogram # now runs as root
Please be careful when using this as it will always execute that program as root no matter who executes it. You can limit access by setting it to your usergroup and deny all execute.
chgrp "${USER}" myprogram # provided you have individual groups set up
chmod a-x myprogram # deny all execute

This approach does not need additional installation of packages.
Terminal=true opens a new terminal window which runs
sudo -i to ask for the password.
Then, using sh to run the program, the Terminal is closed and myprogram runs in the background because it has a & at the end.
[Desktop Entry]
Type=Application
Name=...
Exec=sudo -i sh -c "myprogram &"
Terminal=true
Request: Please report if it works under your OS.
Tested under:
Xubuntu

The pkexec solution from askubuntu:
Exec=pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY APP_COMMAND

Try adding this to .desktop
Path=/path/to/myprogram

Related

Plesk-Scheduled-Tasks reporting "No such file or directory"

I have a working Centos/Plesk (18.0.40 Update #1) environment running Plesk-Scheduled-Tasks with no problems, and I have a new machine that should be a duplicate of that machine (Plesk 18.0.42 Update #1) that is failing to run the Plesk-Scheduled-Tasks (reporting "No such file or directory" on all the tasks that I have added).
Eliminating as many permissions factors as possible, I am testing a scriptless task running "whoami" will work on the original machine but shows an "-: whoami: command not found" error message on the new.
Note, I am also declaring tasks at the domain level - if I was to add a top level task (where it prompts you for the System user) then it can use root and therefore works - but I do not want these tasks to run under root.
Clicking "Run Now" gives the following:
Hiho.
The run scheduled tasks and also the shell access if it´s enabled for your subscription is mostly chrooted. So you have only a minimum on commands which you can use here.
If you open your subscription via FTP Client you should see a bin folder in there. In the bin folder are all commands you are able to use in the chrooted shell.
Example on one of my subscriptions:
bash cat chmod cp curl du false grep groups gunzip gzip head id less ln ls
mkdir more mv pwd rm rmdir scp sh tail tar touch true unrar unzip vi wget

Change ownership of dir to user when running program in sudo

I have a program that I need to run with sudo. I create a directory using mkdir, but this directory has owner and group set to root. That makes sense since I am using sudo. I would like to change the owner and group to the normal user, but I'm not sure how to do that. I thought running system("chown $USER:$USER /directory/") would work, but I suppose since I am in sudo it will just set to root. I was looking into using chown, but I wasn't sure how I was supposed to get the owner and group id. Also it would be good for it to be portable, so I don't want to just hardcode a user/group id.
You're mostly on the right path already, chown is the command you're looking for here.
You can string the two commands to make and then own the directory together using a semicolon.
sudo mkdir test ; sudo chown $USER:$USER test
I've tested this on ubuntu 18.04 and ubuntu 20.04 as that's your tag. The $USER variable resolves to the user that you originally logged in as, not root, as long as you're using it at the beginning of your command like the above. Note that you need to call sudo again when doing the chown portion, the ; ends the sudo elevation.
The coreutils package includes an useful little command, install, you can use instead of mkdir in a sudo context. For example,
sudo install -o USER -g GROUP -m MODE -d DIRECTORY
where USER is the user to own the directory DIRECTORY, GROUP is the group to own the directory, and MODE is the access mode (like chmod) to the directory.
Because system(COMMAND) and popen(COMMAND,...) actually run /bin/sh with -c and COMMAND as parameters, you can use the form
sudo install -o $(id -u) -g $(id -g) -m u=rwx,g=r-x,o=x DIRECTORY
where the shell replaces the user and group names (or rather, numbers, since I'm not using the -n option) before executing sudo. (The id command is also included in coreutils, so you can definitely expect both install and id to be available on all full-blown Linux machines; and even on most embedded systems. It is what all package managers et cetera use to install files, you see.)
Above, I used the mode u=rwx,g=r-x,o=x (equivalently, 0751) as an example; it sets the mode to rwxr-x--x, i.e. grants access to everybody, with owner user and group being able to list the directory contents, and only the owner user being able to create new files or directories in it.

How to disable linux space randomization via dockerfile?

I'm trying to disable randomization via Dockerfile:
RUN sudo echo 0 | sudo tee /proc/sys/kernel/randomize_va_space
but I get
Step 9 : RUN sudo echo 0 | sudo tee /proc/sys/kernel/randomize_va_space
---> Running in 0f69e9ac1b6e
[91mtee: /proc/sys/kernel/randomize_va_space: Read-only file system
any way to work around this? (I see its saying read-only file system any way to get around this?) If its something which the kernel does this means it's outside of my container scope, in that case how am i supposed to work with gdb inside my container? please note this is my target to work with gdb in a container because i'm experimenting with it, so i wanted a container which encapsulates gcc and gdb which i'll use for experimentations.
In host
run:
sudo echo 0 | sudo tee /proc/sys/kernel/randomize_va_space
not in docker
Docker has syntax for modifying some of the sysctls (not via dockerfile though) and kernel.randomize_va_space does not seem to be one of them.
Since you've said you're interested in running gcc/gdb you could disable ASLR only for these binaries with:
setarch `uname -m` -R /path/to/gcc/gdb
Also see other answers in this question.
Sounds like you are building a container for development on your own computer. Unlike production environment, you could (and probably should) opt for a privileged container. In a privileged container sysfs is mounted read-write, so you can control kernel parameters as you would on the host. This is an example of Amazon Linux container I use to develop for on my Debian desktop, which shows the difference
$ docker run --rm -it amazonlinux
bash-4.2# grep ^sysfs /etc/mtab
sysfs /sys sysfs ro,nosuid,nodev,noexec,relatime 0 0
bash-4.2# exit
$ docker run --rm -it --privileged amazonlinux
bash-4.2# grep ^sysfs /etc/mtab
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
bash-4.2# exit
$
Notice ro mount in the unprivileged, rw in the privileged case.
Note that the Dockerfile command
RUN sudo echo 0 | sudo tee /proc/sys/kernel/randomize_va_space
makes no sense. It will be executed (a) during container build time (b) on the machine where you build the image. You want (a) happen at container's run time and (b) on the machine where you run the container. If you need to change sysctls on image start, write a script which does all the setup and then drops you into the interactive shell, like placing a script into e.g. /root and setting it as the ENTRYPOINT
#!/bin/sh
sudo sysctl kernel.randomize_va_space=0
exec /bin/bash -l
(Assuming you mount host working directory into /home/jas that's a good practice, as bash will read your startup files etc).
You need to make sure you have the same UID and GID inside the container, and can do sudo. How you enable sudo depends on a distro. In Debian, members of the sudo group have unrestricted sudo access, while on Amazon Linux (and, IIRC, other RedHat-like system, the group wheel has. Usually this boils down to an unwieldy run command that you rather want to script than type, like
docker run -it -v $HOME:$HOME -w $HOME -u $(id -u):$(id -g) --group-add wheel amazonlinux-devenv
Since your primary UID and GID match the host, files in mounted host directories won't end up owned by root. An alternative is create a bona fide user for yourself during image build (i.e., in the Dockerfile), but I find this more error-prone, because I can end up running this devenv image where my username has a different UID, and that will cause problems. The use of id(1) in a startup command guarantees UID match.

Compile for Chromebook using Crouton

I currently have an Asus c300 chromebook. Since it doesn't have legacy boot, I'm using crouton to get a more standard command line environment. I was able to install gcc very easily in the chroot environment. It works very well under chroot.
Since the underlying hardware is the same, I thought the resulting executable should work for chromebook, without me being in the chroot environment. If true, I thought I could go into the chroot environment, compile whatever program I want/need, and exit back out to the regular environment and use it.
I tried it with a simple hello world program. When I tried to run the executable, I got the following error:
bash: ./a.out: Permission denied.
I tried to run it with sudo, and I get a similar error:
sudo: unable to execute ./a.out: Permission denied.
I even used su to login as root, and I still could not run the program (got the first error).
I thought su/sudo would override any kind of permission restriction. But, it's apparently not the case on the chromebook.
What am I missing? Is what I want to do possible?
EDIT: File permission was already set to 777.
You might simply have to change the permissions of the file or check the files ownership. umask determines weather or not a file that is created gets execute permissions by default. What does -ls -lat on the file reveal?
Also try running
chmod +x ./a.out
You can find more details of error with strace command
use:
strace ./a.out and check output.
I suppose you have different env (path and LD_library_path) under the chroot.

Logging into Cygwin and executing commands using bat file in windows

I am using windows XP operating system and cygwin is installed in my C drive.
I need to login to cygwin directly to my directory path which contains a makefile and also a bash script called build.sh in the same directory. So i modified the original cygwin.bat file and added the line as shown below.
#echo off
C:
chdir C:\cygwin\bin
bash --login "/cygdrive/E/scheme_31july/build/build.sh"
When i double click on this bat file i could see my script executing but not on cygwin shell but on windows cmd shell as a result I get errors for "make" command like "No rule to make target" as make comes bundled with cygwin.
And when I explicitly login to cygwin using default cygwin.bat file and execute my script by giving following commands in cygwin shell the script executes without errors.
Basically I want to write a bat file so that I can keep it anywhere in my PC and instead of manually openeing the cygwin prompt and typing commands like:
$ cd /cygdrive/E/scheme_31july/build/
$ sh build.sh
it should happen automatically. I sit possible to do so.
Regards,
Harshit
No rule to make target sounds more like make being executed in the wrong directory. make itself seems to be available and running as intended.
Try this:
bash --login -c "cd /cygdrive/E/scheme_31july/build/ && sh build.sh"
This should start a --login session (which should give you access to all the settings and tools you'd expect in a cygwin prompt environment), then execute the given shell command, which is the cd and sh you asked for. You could also write those two lines to a separate script file, and pass the name of that to bash instead of the full path to build.sh.
You could also try to cd into C:\scheme_31july\build in the bat file and then execute bash from there. Not sure whether bash will try to change path upon entering the login session. You can try whether things work without the --login, both for this approach and the one above.
#echo off
C:
cd C:\scheme_31july\build
C:\cygwin\bin\bash.exe ./build.sh
I'm not sure whether you want the session to turn interactive after that or not. In the above case, bash will terminate after the script completed, and might even close the window. You might have to add a read into build.sh to avoid that. If you want bash to turn interactive after executing some command, you can try using the --rcfile option of bash to execute some commands and then turn interactive.

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