cpio.sh

   1 #!/bin/sh
   2 #
   3 # Emulates some cpio behavior using GNU tar
   4
   5 die() {
   6         echo >&2 "$@"
   7         exit 1
   8 }
   9
  10 null=
  11
  12 while test $# -gt 0; do
  13         case "$1" in
  14         -0)     null=--null;;
  15         -o)     mode=o;;
  16         -iuv)   ;;
  17         -pumd|-pumdl)
  18                 mode=p
  19                 dir="$2"
  20                 shift
  21                 ;;
  22         *)      die "cpio emulation supports only -0, -o, -iuv, -pumdl";;
  23         esac
  24         shift
  25 done
  26
  27 filterdirs() {
  28         while read f; do
  29                 if test -d "$f"; then
  30                         # list only empty directories
  31                         if test -z "$(ls -A "$f")"; then
  32                                 echo "$f"
  33                         fi
  34                 else
  35                         echo "$f"
  36                 fi
  37         done
  38 }
  39
  40 case $mode in
  41 o)
  42         tar --create --file=- $null --files-from=-
  43         ;;
  44 p)
  45         test -z "$null" || die "cpio: cannot use -0 in pass-through mode"
  46         filterdirs |
  47         tar --create --file=- --files-from=- |
  48         tar --extract --directory="$dir" --file=-
  49         ;;
  50 *)
  51         tar xvf -
  52 esac