Why does this script running su never seem to terminate if I change user inside the script?

  1. su vlado will need a password unless run as root.
  2. su vlado will wait for input
  3. commands after su valdo are not executed inside su, but after exiting su valdo

what happen

cd /var/www/html/tatrytec.eu  # change dir

git pull # pull git repos

# Change user bacause of composer install warrning
su vlado # either ask password or wait for input

composer install  --no-scripts # if this get executed, you are no longer as vlado

  • the key point is that su vlado will fork a new shell, that will ignore (as is) following line in original bash script.
  • when copy/pasting you don't have that limitation (as you copy inside vlado's new shell)

I try to explain in more details which user/what happen

cd /var/www/html/tatrytec.eu  # ROOT change dir

git pull # ROOT pull git repos

# Change user bacause of composer install warrning
su vlado # VLADO wait for input
new shells as VLADO> sample command
new shells as VALDO> exit

composer install  --no-scripts # ROOT run composer

proposed correction

as root

#!/bin/bash
# Run this script as bash command like: bash create-apache-site.sh

cd /var/www/html/tatrytec.eu

git pull

# Change user bacause of composer install warrning
su vlado  <<EOF

composer install  --no-scripts

npm install --production

EOF

where

  • su vlado << EOF ... EOF will feed all lines to su vlado

Use this instead:

#!/bin/bash
# Run this script as bash command like: bash create-apache-site.sh

cd /var/www/html/tatrytec.eu

git pull

# Change user bacause of composer install warrning
su vlado -c 'composer install  --no-scripts; npm install --production'

The -c or --command option for su allows you to run a command.