.bin/custom-chroot

   1 #!/bin/bash -e
   2
   3 [[ -w / ]] || exec sudo env HOME="$HOME" "$0" "$@"
   4
   5 mounts="proc sys dev dev/pts usr/portage usr/portage/distfiles"
   6
   7 chroot=${0%/*}
   8 case ${chroot} in
   9         .) chroot=${PWD} ;;
  10         ./*) chroot=${PWD}/${chroot#./} ;;
  11 esac
  12 cd "${chroot}"
  13
  14 do_umount() {
  15         mounts=$(mount | grep ${chroot} | awk '{print $3}' | tac)
  16         for m in ${mounts} ; do
  17                 echo "unmounting $m"
  18                 umount $m
  19         done
  20         if [[ -z ${mounts} ]] ; then
  21                 echo "nothing mounted in ${chroot}"
  22         fi
  23         exit 0
  24 }
  25
  26 while [[ -n $1 ]] ; do
  27         case $1 in
  28                 -u) do_umount ;;
  29                 -*) echo "unknown option $1"; exit 1 ;;
  30                 *)  break ;;
  31         esac
  32 done
  33
  34 maybe_mount() {
  35         local src=/$1 dst=${chroot}/${2:-$1}
  36         [[ -d ${src} ]] || return 0
  37         mkdir -p "${dst}"
  38         grep -sq "${dst}" /proc/mounts || mount --bind "${src}" "${dst}"
  39 }
  40 for m in ${mounts} ; do
  41         maybe_mount ${m}
  42 done
  43
  44 get_type() {
  45         case $(file "$1") in
  46                 *x86-64*)         echo x86_64;;
  47                 *"Intel 80386"*)  echo i386;;
  48                 *32-bit*PowerPC*) echo ppc;;
  49                 *64-bit*PowerPC*) echo ppc64;;
  50         esac
  51 }
  52 bin_dst=$(get_type bin/bash)
  53 if [[ -n ${bin_dst} ]] && type -P setarch &>/dev/null ; then
  54         setarch="setarch ${bin_dst}"
  55 fi
  56
  57 if [[ ! -L etc/mtab ]] ; then
  58         rm -f etc/mtab
  59         ln -sf /proc/mounts etc/mtab
  60 fi
  61 etc="
  62         hosts
  63         locale.gen
  64         localtime
  65         resolv.conf
  66 "
  67 home="
  68         .inputrc
  69         .gdbinit
  70         .gitconfig
  71         .nanorc
  72 "
  73 for f in \
  74         $(printf 'etc/%s ' ${etc}) \
  75 ; do
  76         if [ -e "/${f}" ] ; then
  77                 cp /${f} ${f}
  78         fi
  79 done
  80 for f in ${home} ; do
  81         cp ~/${f} root/${f}
  82 done
  83
  84 unset LS_COLORS # format changes over time
  85 [[ $# -eq 0 ]] && set -- env HOME=/root /bin/bash -l
  86 exec \
  87         ${setarch} \
  88         chroot "${chroot}" \
  89         "$@"