bazzite/system_files/deck/shared/usr/libexec/os-branch-select

#!/usr/bin/bash

if [ -x /usr/bin/hhd.steamos ]; then
  /usr/bin/pkexec /usr/bin/hhd.steamos steamos-select-branch --fallback $@
  ret=$?
  # If ret is not 20, exit with the return code, otherwise continue
  if [ $ret -ne 20 ]; then
    exit $ret
  fi
fi

set -e

source /etc/os-release

if [[ $# -eq 1 ]]; then
  case "$1" in
    -c)
      if [[ -f /var/ublue-update/branch ]]; then
        branch=$(cat /var/ublue-update/branch)
      else
        branch=$(cut -d ":" -f4 <<< "$(rpm-ostree status --booted | grep -m 1 $ID)")
      fi

      # Trim and convert to lowercase
      branch=$(echo "$branch" | tr '[:upper:]' '[:lower:]' | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
      case $branch in
        latest|stable)
          echo rel
          exit 0
          ;;
        testing)
          echo rc
          exit 0
          ;;
        unstable)
          echo main
          exit 0
          ;;
        *)
          # This can happen on CI builds or when downgrading from a newer build that knows of more branches.  The update
          # path should decide how to handle it.
          echo >&2 "Warning: Unrecognized currently selected branch name '$branch', updates may not succeed."
          echo "$branch"
          exit 0
          ;;
      esac
      ;;
    -l)
      echo rel
      echo rc
      echo beta
      echo bc
      echo main
      exit 0
      ;;
    rel|latest|stable)
      /usr/bin/pkexec /usr/libexec/ublue-update-rebase "stable"
      exit 0
      ;;
    rc|beta|testing)
      /usr/bin/pkexec /usr/libexec/ublue-update-rebase "testing"
      exit 0
      ;;
    bc|main|unstable)
      echo "The unstable branch has a high risk of breaking."
      echo "Do NOT use it unless you know what you are doing."
      /usr/bin/pkexec /usr/libexec/ublue-update-rebase "unstable"
      exit 0
      ;;
  esac
fi

echo "Usage: steamos-select-branch <stable|testing|unstable>" 1>&2