I've written a script that takes, as an argument, a string that is a concatenation of a username and a project. The script is supposed to switch (su) to the username, cd to a specific directory based upon the project string.
I basically want to do:
su $USERNAME;
cd /home/$USERNAME/$PROJECT;
svn update;
The problem is that once I do an su... it just waits there. Which makes sense since the flow of execution has passed to switching to the user. Once I exit, then the rest of the things execute but it doesn't work as desired.
I prepended su to the svn command but the command failed (i.e. it didn't update svn in the directory desired).
How do I write a script that allows the user to switch user and invoke svn (among other things)?
Much simpler: use sudo to run a shell and use a heredoc to feed it commands.
#!/usr/bin/env bash
whoami
sudo -i -u someuser bash << EOF
echo "In"
whoami
EOF
echo "Out"
whoami
(answer originally on SuperUser)
The trick is to use "sudo" command instead of "su"
You may need to add this
username1 ALL=(username2) NOPASSWD: /path/to/svn
to your /etc/sudoers file
and change your script to:
sudo -u username2 -H sh -c "cd /home/$USERNAME/$PROJECT; svn update"
Where username2 is the user you want to run the SVN command as and username1 is the user running the script.
If you need multiple users to run this script, use a %groupname instead of the username1
You need to execute all the different-user commands as their own script. If it's just one, or a few commands, then inline should work. If it's lots of commands then it's probably best to move them to their own file.
su -c "cd /home/$USERNAME/$PROJECT ; svn update" -m "$USERNAME"
Here is yet another approach, which was more convenient in my case (I just wanted to drop root privileges and do the rest of my script from restricted user): you can make the script restart itself from the correct user. This approach is more readable than using sudo or su -c with a "nested script". Let's suppose it is started as root initially. Then the code will look like this:
#!/bin/bash
if [ $UID -eq 0 ]; then
user=$1
dir=$2
shift 2 # if you need some other parameters
cd "$dir"
exec su "$user" "$0" -- "$#"
# nothing will be executed beyond that line,
# because exec replaces running process with the new one
fi
echo "This will be run from user $UID"
...
Use a script like the following to execute the rest or part of the script under another user:
#!/bin/sh
id
exec sudo -u transmission /bin/sh - << eof
id
eof
Use sudo instead
EDIT: As Douglas pointed out, you can not use cd in sudo since it is not an external command. You have to run the commands in a subshell to make the cd work.
sudo -u $USERNAME -H sh -c "cd ~/$PROJECT; svn update"
sudo -u $USERNAME -H cd ~/$PROJECT
sudo -u $USERNAME svn update
You may be asked to input that user's password, but only once.
It's not possible to change user within a shell script. Workarounds using sudo described in other answers are probably your best bet.
If you're mad enough to run perl scripts as root, you can do this with the $< $( $> $) variables which hold real/effective uid/gid, e.g.:
#!/usr/bin/perl -w
$user = shift;
if (!$<) {
$> = getpwnam $user;
$) = getgrnam $user;
} else {
die 'must be root to change uid';
}
system('whoami');
This worked for me
I split out my "provisioning" from my "startup".
# Configure everything else ready to run
config.vm.provision :shell, path: "provision.sh"
config.vm.provision :shell, path: "start_env.sh", run: "always"
then in my start_env.sh
#!/usr/bin/env bash
echo "Starting Server Env"
#java -jar /usr/lib/node_modules/selenium-server-standalone-jar/jar/selenium-server-standalone-2.40.0.jar &
#(cd /vagrant_projects/myproj && sudo -u vagrant -H sh -c "nohup npm install 0<&- &>/dev/null &;bower install 0<&- &>/dev/null &")
cd /vagrant_projects/myproj
nohup grunt connect:server:keepalive 0<&- &>/dev/null &
nohup apimocker -c /vagrant_projects/myproj/mock_api_data/config.json 0<&- &>/dev/null &
Inspired by the idea from #MarSoft but I changed the lines like the following:
USERNAME='desireduser'
COMMAND=$0
COMMANDARGS="$(printf " %q" "${#}")"
if [ $(whoami) != "$USERNAME" ]; then
exec sudo -E su $USERNAME -c "/usr/bin/bash -l $COMMAND $COMMANDARGS"
exit
fi
I have used sudo to allow a password less execution of the script. If you want to enter a password for the user, remove the sudo. If you do not need the environment variables, remove -E from sudo.
The /usr/bin/bash -l ensures, that the profile.d scripts are executed for an initialized environment.
I'm trying to understand how to run commands from my user account in a script with root privileges. I've got this test script and the output is confusing me.
~$ cat test.sh
output:
#!/usr/bin/bash
su -c "whoami" user
su -c "echo $HOME" user
~$ sudo ./test.sh
output:
user
/root
Why does the first 'su' command seem to run as 'user' but the second seems to run as 'root'?
Double quotes expand shell variables. Try
echo su -c "echo $HOME" user
to see what I mean. It's the shell running the script that expands $HOME, which runs as root (from sudo ./test.sh). So what ends up being run is su -c 'echo /root' user.
You want
su -c 'echo $HOME' user
Here we pass echo $HOME unexpanded to su -c.
I wrote a shell script like this
#!/bin/bash
sudo mkdir /var/www/html/test
sudo cp ./index.html /var/www/html/test/index.html
echo "Hi" > /var/www/html/test/index.html
if I runt this with sudo it works well.
$ sudo ./script.sh
but I don't want to run with sudo. because echo doesn't need root privilege. In other hand if I run this without sudo like this:
$ ./script.sh
for the first command (mkdir) it asks me for root password and second command doesn't run and give me a permission denied error.
How can I handle this situation?
Based on your setup, e.g. in ubuntu if I run sudo 2 times, the second time I don't have to give the password. So it is possible that the second sudo DID run, without asking for password again.
You can clarify, try this:
sudo echo a
sudo echo b
It is most likely, as Kip K commented, the error originates from the echo "Hi"... since the normal user has no permission to write /var/www/html/test/index.html .
Kinda overkill, but you can give constant feedback like this:
sudo bash -c 'echo mkdir; mkdir /var/www/html/test'
sudo bash -c 'echo cp; cp ./index.html /var/www/html/test/index.html'
Try chown for directory test:
#!/bin/bash
sudo bash -c 'mkdir /var/www/html/test && chown -R USER /var/www/html/test'
cp ./index.html /var/www/html/test/index.html
echo "Hi" > /var/www/html/test/index.html
or ... chmod o+w /var/www/html/test
I have a single command to ssh to a remote linux host and execute a shell script.
ssh -t -t $USER#somehost 'bash -s' < ./deploy.sh
Inside deploy.sh I have this:
#!/bin/bash
whoami; # I see this command echo
sudo -i -u someoneelse #I see this command echo
whoami; # I DON'T see this command echo, but response is correct
#subsequent commands don't echo
When I run the deploy.sh script locally all commands echo.
How do I get commands to echo after I sudo as another user over ssh?
Had to set -x AFTER sudo as another user
#!/bin/bash
whoami;
sudo -i -u someonelese
set -x #make sure echo on
whoami; #command echoed
I am trying to execute the following command but the output is not coming as required.
var=$(echo "<password>"|sudo -S su -l <user> -c "<command>")
Please help if anyone can?
Expected Result:
var=$(echo ""|sudo -S su -l -c "pwd")
echo $var /home/bhushan
$:
Actual Result:
echo $var
$:
You can use backticks
var=`sudo -S su -l -c ""`
or the $(command) syntax
var=$(sudo -S su -l -c "")
(keep in mind though that sudo -S su -l -c "" doesn't output anything so $var will be empty)
You can workaround it by storing the output of the command into a file, then change its permission so that all users will see it and in a following command load it from the file:
sudo -S "<command> > /tmp/sudocmd.out && chmod 644 /tmp/sudocmd.out"
var=$(cat /tmp/sudocmd.out)