tests/dd/sparse.sh

   1 #!/bin/sh
   2
   3 # Copyright (C) 2012 Free Software Foundation, Inc.
   4
   5 # This program is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or
   8 # (at your option) any later version.
   9
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  19 print_ver_ dd
  20 require_sparse_support_
  21
  22 # Ensure basic sparse generation works
  23 truncate -s1M sparse
  24 dd bs=32K if=sparse of=sparse.dd conv=sparse
  25 test $(stat -c %s sparse) = $(stat -c %s sparse.dd) || fail=1
  26
  27 # Demonstrate that conv=sparse with oflag=append,
  28 # will do ineffective seeks in the output
  29 printf 'a\000\000b' > file.in
  30 printf 'ab' > exp
  31 dd if=file.in bs=1 conv=sparse oflag=append > out
  32 compare exp out || fail=1
  33
  34 # Demonstrate conv=sparse with conv=notrunc,
  35 # where data in file.out is not overwritten with NULs
  36 printf '____' > out
  37 printf 'a__b' > exp
  38 dd if=file.in bs=1 conv=sparse,notrunc of=out
  39 compare exp out || fail=1
  40
  41 # Ensure we fall back to write if seek fails
  42 dd if=file.in bs=1 conv=sparse | cat > file.out
  43 cmp file.in file.out || fail=1
  44
  45 # Setup for block size tests: create a 3MiB file with a 1MiB
  46 # stretch of NUL bytes in the middle.
  47 rm -f file.in
  48 dd if=/dev/urandom of=file.in bs=1M count=3 iflag=fullblock || fail=1
  49 dd if=/dev/zero    of=file.in bs=1M count=1 seek=1 conv=notrunc || fail=1
  50
  51 kb_alloc() { du -k "$1"|cut -f1; }
  52
  53 # If our just-created input file appears to be too small,
  54 # skip the remaining tests.  On at least Solaris 10 with NFS,
  55 # file.in is reported to occupy <= 1KiB for about 50 seconds
  56 # after its creation.
  57 if test $(kb_alloc file.in) -gt 3000; then
  58
  59   # Ensure NUL blocks smaller than the block size are not made sparse.
  60   # Here, with a 2MiB block size, dd's conv=sparse must *not* introduce a hole.
  61   dd if=file.in of=file.out bs=2M conv=sparse
  62   test 2500 -lt $(kb_alloc file.out) || fail=1
  63
  64   # Ensure that this 1MiB string of NULs *is* converted to a hole.
  65   dd if=file.in of=file.out bs=1M conv=sparse
  66   test $(kb_alloc file.out) -lt 2500 || fail=1
  67
  68 fi
  69
  70 Exit $fail