bash 编程 STDIN 重定向

Question

I want to get the home directory of a user of a unix system. Why doesn't the following work:

# sudo su $offender -c "bash -s < <(echo echo \$HOME)"
sh: Syntax error: redirection unexpected

Answer 1

It works for me in Ubuntu and Fedora using sudo su $offender -c "echo \$HOME"

You could also gouge it from your /etc/passwd file like so:

grep "^$offender" /etc/passwd | cut -d':' -f6

Answer 2

Don't really know why it doesn't work, but here's a way to get the home directory that does not involve spawning a shell as that user:

getent passwd "${offender:?No Offending Account Given}" | awk -F':' 'NR==1{print $6}'

Answer 3

The direct problem is that sh does not recognize process substitution (the <(echo $HOME) ) notation, even when it is a link to bash .

It seems like a rather brute force way to get the information. Doesn't:

eval echo ~$offender

work for you?