1#!/bin/sh 2# test dd reblocking vs. bs= 3 4# Copyright (C) 2008-2023 Free Software Foundation, Inc. 5 6# This program is free software: you can redistribute it and/or modify 7# it under the terms of the GNU General Public License as published by 8# the Free Software Foundation, either version 3 of the License, or 9# (at your option) any later version. 10 11# This program is distributed in the hope that it will be useful, 12# but WITHOUT ANY WARRANTY; without even the implied warranty of 13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14# GNU General Public License for more details. 15 16# You should have received a copy of the GNU General Public License 17# along with this program. If not, see <https://www.gnu.org/licenses/>. 18 19. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src 20print_ver_ dd 21 22# 2 short reads -> 1 full write + 1 partial write 23cat <<\EOF > exp-reblock || framework_failure_ 240+2 records in 251+1 records out 264 bytes copied 27EOF 28 29# 2 short reads -> 2 partial writes 30cat <<\EOF > exp-no-reblock || framework_failure_ 310+2 records in 320+2 records out 334 bytes copied 34EOF 35 36 37# Use a fifo rather than a pipe in the tests below 38# so that the producer (printf subshell) will wait 39# until the consumer (dd) opens the fifo therefore 40# increasing the chance that dd will read the data 41# from each printf separately. 42mkfifo_or_skip_ dd.fifo 43 44dd_reblock_1() 45{ 46 local delay="$1" 47 48 # ensure that dd reblocks when bs= is not specified 49 dd ibs=3 obs=3 if=dd.fifo > out 2> err& 50 (printf 'ab'; sleep $delay; printf 'cd') > dd.fifo 51 wait #for dd to complete 52 sed 's/,.*//' err > k && mv k err 53 compare exp-reblock err 54} 55 56retry_delay_ dd_reblock_1 .1 6 || fail=1 57 58dd_reblock_2() 59{ 60 local delay="$1" 61 62 # Demonstrate that bs=N supersedes even following ibs= and obs= settings. 63 dd bs=3 ibs=1 obs=1 if=dd.fifo > out 2> err& 64 (printf 'ab'; sleep $delay; printf 'cd') > dd.fifo 65 wait #for dd to complete 66 sed 's/,.*//' err > k && mv k err 67 compare exp-no-reblock err 68} 69 70retry_delay_ dd_reblock_2 .1 6 || fail=1 71 72Exit $fail 73