Bash root to user. Best in same or separate script?

Question

I'm working on a Linux Bash script that needs to start as root. At the end of the script, it builds a list of packages. This requires running as user. Then it will move the packages, which needs to run as root again. I have sudo set up, but want to keep the script as generic as possible. I've tried the following and slight variations of it in the first script to switch from root to user. su -c - "$USER" "export PKGDEST=/tmp/test/AUR/" su -c - "$USER" "pacaur --noconfirm --noedit -cm" "$(< /tmp/test/aur)" The second line fails to run properly resulting in different errors, depending quote combination and placement. Running the lines within the first script as shown above produced the following error after reading the file /tmp/test/aur :: no targets specified (use -h for help). My preference would be getting this single script method to work properly. Google, etc. said root, user, root in bash is bad, so tried break it into 3 parts: The first script runs as root. The problem centers here, can't get it to start the second. Second script runs as user, starts 3rd script as root with: sudo /bin/bash "$L"/copyaur.sh Third script, copyaur.sh runs, moving the packages properly but doesn't show as running in the terminal because calls new shell? Below was ran as su in a user terminal during testing. Prefer using the $USER var in the script. As su in the terminal, then back to su - $USER, then ls in home lists my normal user name [dom's] contents. [dom@arch testing]$ echo $USER dom [root@arch testing]# echo $USER dom [root@arch testing]# pwd /home/dom/scripts/testing I get the following results in testing, starting as su in the terminal. Want to get $USER var to work in place of dom. su - $USER home/$USER/scripts/testing/buildaur.sh - No such file or directory su --login $USER home/$USER/scripts/testing/buildaur.sh - No such file or directory su - $USER home/dom/scripts/testing/buildaur.sh - No such file or directory su - "$USER" home/dom/scripts/testing/buildaur.sh - No such file or directory su - "$USER" ./buildaur.sh - No such file or directory su - dom ./buildaur.sh - No such file or directory su - dom ~/scripts/testing/buildaur.sh - Permission denied su - $USER ~/scripts/testing/buildaur.sh - Permission denied su --login dom ~/scripts/testing/buildaur.sh - Permission denied su - dom /home/dom/scripts/testing/buildaur.sh - Runs as user, expected su --login dom /home/dom/scripts/testing/buildaur.sh - Runs as user, expected su - dom /home/$USER/scripts/testing/buildaur.sh - Runs as user, expected 9/19/2014 EDIT TO ADD REQUESTED INFO Here's part of the script. Still no solution. This latest variation has made it through building the first package from the list before failing. It does however complete the next line, which is the last command in the script. Keep in mind this command works fine outside of using it with the proceeding su -c - "$USER" "pacaur --noconfirm --noedit -cm $(< /tmp/makeiso/aur)" #!/bin/bash ## makeiso.sh must be run as root within /home/"$USER"/makeiso/releng ## makeiso dependancies: archiso pacaur ############################################################################# # Accessing an empty variable will yield an error set -u # Check if root # Print message to user echo "Checking if we're running as root" if [[ $EUID -ne 0 ]]; then echo "This script must be run as root" 1>&2 exit 1 fi # echo for a space echo "" # If passed root test, send message print message to user if [[ $EUID = 0 ]]; then echo "Passed root test, proceeding" fi ################################################## ################################################## Line 180 of the script running as root....... ################################################## # Print message to user echo "Copying system configuration files" set -x # Create directory for following command mkdir -p /tmp/makeiso/ # Create a list of modified config files pacman -Qii | awk '/^MODIFIED/ {print $2}' >> /tmp/makeiso/rtmodconfig.list # Create destination directory for the following command mkdir -p "$L"/airootfs/makeiso/configs/rootconfigs # Copy above list to releng for later use cp /tmp/makeiso/rtmodconfig.list "$L"/airootfs/makeiso/configs/rootconfigs/rtmodconfig.list # Read rtmodconfig.list and copy the modified config files to releng xargs -a /tmp/makeiso/rtmodconfig.list cp -t "$L"/airootfs/makeiso/configs/rootconfigs/ # Set makepkg variable to define where to send built packages su -c - "$USER" "export PKGDEST=/tmp/makeiso/AUR" # Build AUR packages from list, /tmp/makepkg/aur ############# su -c - "$USER" "pacaur --noconfirm --noedit -cm $(< /tmp/makeiso/aur)" ############# # Copy the prebuilt AUR packages to releng cp -R /tmp/makeiso/AUR "$L"/airootfs/makeiso/packages/AUR Here's the output with set -x. I'm using pacaur to build the packages, which uses cower and makepkg. It seems like either pacaur or makepkg is loosing track of the file with the list of packages to build, and doesn't recognize the package names as commands. + su -c - dom 'export PKGDEST=/tmp/makeiso/AUR' + su -c - dom 'pacaur --noconfirm --noedit -cm bootinfoscript cairo-ubuntu cower fontconfig-ubuntu freetype2-ubuntu gnome-colors-icon-theme gnome-colors-icon-theme-extras gnome-icon-theme-xfce google-chrome grub-legacy libxfcegui4 pacaur package-query pkgbrowser ttf-ms-fonts virtualbox-ext-oracle vivaldi xfce4-quicklauncher-plugin' :: resolving dependencies... :: looking for inter-conflicts... AUR Packages (1): bootinfoscript-0.61-1 :: Retrieving package(s)... sudo: no tty present and no askpass program specified :: Checking bootinfoscript integrity... ==> Making package: bootinfoscript 0.61-1 (Sat Sep 19 22:27:37 PDT 2015) ==> Retrieving sources... -> Found bootinfoscript-061.tar.gz ==> Validating source files with md5sums... bootinfoscript-061.tar.gz ... Passed :: Building bootinfoscript package(s)... ==> Making package: bootinfoscript 0.61-1 (Sat Sep 19 22:27:38 PDT 2015) ==> Checking runtime dependencies... ==> Checking buildtime dependencies... ==> Retrieving sources... -> Found bootinfoscript-061.tar.gz ==> Validating source files with md5sums... bootinfoscript-061.tar.gz ... Passed ==> Extracting sources... -> Extracting bootinfoscript-061.tar.gz with bsdtar ==> Removing existing $pkgdir/ directory... ==> Entering fakeroot environment... ==> Starting package()... ==> Tidying install... -> Purging unwanted files... -> Removing libtool files... -> Removing static library files... -> Compressing man and info pages... -> Stripping unneeded symbols from binaries and libraries... ==> Creating package "bootinfoscript"... -> Generating .PKGINFO file... -> Generating .MTREE file... -> Compressing package... ==> Leaving fakeroot environment. ==> Finished making: bootinfoscript 0.61-1 (Sat Sep 19 22:27:38 PDT 2015) :: bootinfoscript cleaning skipped bash: line 1: cairo-ubuntu: command not found error: no operation specified (use -h for help) bash: line 3: fontconfig-ubuntu: command not found bash: line 4: freetype2-ubuntu: command not found bash: line 5: gnome-colors-icon-theme: command not found bash: line 6: gnome-colors-icon-theme-extras: command not found bash: line 7: gnome-icon-theme-xfce: command not found bash: line 8: google-chrome: command not found bash: line 9: grub-legacy: command not found bash: line 10: libxfcegui4: command not found error: no operation specified (use -h for help) bash: line 14: ttf-ms-fonts: command not found bash: line 15: virtualbox-ext-oracle: command not found bash: line 16: vivaldi: command not found bash: line 17: xfce4-quicklauncher-plugin: command not found + cp -R /tmp/makeiso/AUR /home/dom/makeiso/releng/airootfs/makeiso/packages/AUR

Dom · Answer

The following worked as needed in my script to switch from root to $USER, then back to root.

sudo -u "$USER" bash << HereTag

command
command
command

# End Here Tag 
HereTag

To review, I'm starting the script like this:

[user@linuxbox ~]$ su
Password: 
[root@linuxbox user]# ./script.sh

After $ su, echo $USER shows my username. Even though I'm starting the script as root, I am prompted for a password @ sudo -u "$USER" bash.

I'm in the wheel group needing to provide password in suoders file.

I'd like to eventually figure out how to accomplish this without the need for sudo, but this will work for now.

Bash root to user. Best in same or separate script?

One Answer

Add your own answers!

Ask a Question