Using chown $USER:$USER inside bash script

Question

In a small bash script I'm running I am attempting to chown a new directory that is created. I've added:

sudo chown $USER:$USER /var/www/$sitename
sudo chmod 775 /var/www/$sitename

after the line where I mkdir (sudo mkdir /var/www/$sitename).

For some reason the chown is not executing. I can execute it manually but when written in the file it doesn't work. I have noticed that "chown" is not highlighted in the same color as "mkdir" and "chmod" but I can't figure out my problem.

Why doesn't chown work here?

Is it an issue with $USER:$USER?

EDIT Here is the full script. How would I chown the file to whichever non root user executed the script?

#!/bin/sh
#!/bin/bash
# New Site

cd /etc/apache2/sites-available/
echo "New site name (test.my):"
read sitename
echo "<VirtualHost *:80>

        ServerAdmin admin@$sitename

    ServerName $sitename

        ServerAlias $sitename

    DocumentRoot /var/www/$sitename

        <Directory />
                Options FollowSymLinks
                AllowOverride All
        </Directory>
        <Directory /var/www/$sitename>
                Options Indexes FollowSymLinks MultiViews
                AllowOverride All
                Order allow,deny
                allow from all
        </Directory>

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined


</VirtualHost>" > $sitename.conf
sudo mkdir /var/www/$sitename
sudo chown $USER:$USER /var/www/$sitename
echo USER is $USER
sudo chmod 775 /var/www/$sitename
sudo a2ensite $sitename.conf
sudo apachectl restart
echo "New site created"

Solution 1

If for some reason, $USER is not set, you can use the id command to obtain the identity of the real user. So the first time you use the $USER variable, you can use the shell expansion to supply a default value. Change the chown line in your script to:

sudo chown "${USER:=$(/usr/bin/id -run)}:$USER" "/var/www/$sitename"

If USER is empty or unset when this is run, bash will set the USER variable to the output of /usr/bin/id -run.

Solution 2

When I calling my script with sudo it would set $USER to root.

$ sudo ./myscript.sh

I tried the chown ${USER:=$(/usr/bin/id -run)}:$USER /var/www/$sitename but it would still return root.

I found if I used who with awk I was able to get the current user that called the script with sudo.

currentuser=$(who | awk '{print $1}')}
chown -R $currentuser:$currentuser /var/www/$sitename`

Solution 3

In order to simplify the problem and since your are getting the variable sitename, why don't you read a username variable?

With that you'd make sure that the script execution is not dependent on the environmental variables made available the way the script is executed.

Comments

[roaima]

The variable is evaluated before the command is executed, so your suggested alternative would make no difference. (Try it with echo chown... and see.)

[Illuminator]

To prevent setting currentuser (sometime) with multiline users, use $(who | awk 'NR==1{print $1}') instead.

[Admin]

(1) who is not guaranteed to produce any output.  (2) If it does, there is no guarantee that the first line of output identifies the current user.  What if somebody ssh’ed into your system?  What if you are ssh’ed into some other system? (3) logname seems to be more reliable.