su -c takes a single string argument, that is passed to $SHELL -c. This makes running more complex commands a quoting nightmare if done by hand. What I would like: A function to turn "$@" into one string, that is parsed by the target shell appropiately. For simplicity lets either assume the target shell is the same as the current shell, or a simple (b)ash.
# Naive implementation:
run_su() {
/bin/sh -c "$*"
# To emulate su targetuser -c
}
run_su echo "double spaces"
# Output: double spaces
# NOte the missing double space
I know sudo will do this the right way. But I don't want to depend on sudo unless we absolutely have to.
# This does the right thing
run_sudo() {
sudo -u targetuser "$@"
}
run_sudo echo "double spaces"
If you can assume bash, it's simple:
/bin/bash -c "$(printf "%q " "$@")"
For POSIX sh:
quote() {
for arg
do
var=$(printf "%sx" "$arg" | sed -e "s/'/'\\\\''/")
var=${var%x}
printf "'%s' " "$var"
done
}
/bin/sh -c "$(quote "$@")"