I want to obtain home dir of any user with echo

echo ~puchuu
>> /home/puchuu

But I cant use variable

echo ~$USER
>> ~puchuu
echo `echo ~$USER`
>> ~puchuu

1

7 Answers

You can use eval:

eval echo ~$USER

But see Andrew's comment and glenn's reply below.

10

This might work for you:

homedir=$( getent passwd "$USER" | cut -d: -f6 )

This will also work on users that are not you. For instance,

homedir=$( getent passwd "someotheruser" | cut -d: -f6 )

1

It seems you are that user -- why not

echo $HOME

?

2

There is a safe way to do this!

on Linux/BSD/macOS/OSX without sudo or root

user=pi
user_home=$(bash -c "cd ~$(printf %q "$user") && pwd")

NOTE: The reason this is safe is because bash (even versions prior to 4.4) has its own printf function that includes:

%q quote the argument in a way that can be reused as shell input

See: help printf

Compare to how other answers respond to code injection

# "ls /" is not dangerous so you can try this on your machine
# But, it could just as easily be "sudo rm -rf /*"
$ user="root; ls /"
$ printf "%q" "$user"
root\;\ ls\ /
# This is what you get when you are PROTECTED from code injection
$ user_home=$(bash -c "cd ~$(printf "%q" "$user") && pwd"); echo $user_home
bash: line 0: cd: ~root; ls /: No such file or directory
# This is what you get when you ARE NOT PROTECTED from code injection
$ user_home=$(bash -c "cd ~$user && pwd"); echo $user_home
bin boot dev etc home lib lib64 media mnt ono opt proc root run sbin srv sys tmp usr var /root
$ user_home=$(eval "echo ~$user"); echo $user_home
/root bin boot dev etc home lib lib64 media mnt ono opt proc root run sbin srv sys tmp usr var

on Linux/BSD/macOS/OSX as root

If you are doing this because you are running something as root then you can use the power of sudo:

user=pi
user_home=$(sudo -u "$user" sh -c 'echo $HOME')

on Linux/BSD (but not modern macOS/OSX) without sudo or root

If not, the you can get it from /etc/passwd. There are already lots of examples of using eval and getent, so I'll give another option:

user=pi
user_home=$(awk -v u="$user" -v FS=':' '$1==u {print $6}' /etc/passwd)

I would really only use that one if I had a bash script with lots of other awk oneliners and no uses of cut. While many people like to "code golf" to use the fewest characters to accomplish a task, I favor "tool golf" because using fewer tools gives your script a smaller "compatibility footprint". Also, it's less man pages for your coworker or future-self to have to read to make sense of it.

2

ZSH users can place the tilde (~) outside the expression. This does not work on Bash:

echo ~`echo $USER`

1

Once you login, run cd to go to your home directory, then run pwd to print the working directory.

2

how about using realpath instead of eval:

realpath ~$USER

because eval can execute anything, where as realpath will not.

3

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