use posix shell for tests

test/Makefile.am

@@ -7,4 +7,4 @@ TESTS = \
 EXTRA_DIST = $(TESTS)
 
 TEST_EXTENSIONS = .sh
-SH_LOG_COMPILER = bash
+SH_LOG_COMPILER = sh

test/compress-file-permissions.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 PIXZ=../src/pixz
 
@@ -10,4 +10,4 @@ echo foo > $INPUT
 
 $PIXZ $INPUT
 
-[[ $(stat -c "%a" $INPUT.xz) = 600 ]]
+[ "$(stat -c "%a" $INPUT.xz)" = 600 ]

test/cppcheck-src.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 if which cppcheck &> /dev/null ; then
   cppcheck --error-exitcode=1 $srcdir/../src

test/single-file-round-trip.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 PIXZ=../src/pixz
 
@@ -11,4 +11,4 @@ trap "rm -f $COMPRESSED $UNCOMPRESSED" EXIT
 $PIXZ $INPUT $COMPRESSED
 $PIXZ -d $COMPRESSED $UNCOMPRESSED
 
-[[ $(cat $INPUT | md5sum) = $(cat $UNCOMPRESSED | md5sum) ]] || exit 1
+[ "$(cat $INPUT | md5sum)" = "$(cat $UNCOMPRESSED | md5sum)" ] || exit 1

test/xz-compatibility-c-option.sh

@@ -1,6 +1,6 @@
-#!/bin/bash
+#!/bin/sh
 
 PIXZ=../src/pixz
 
-[[ "foo" = $(echo foo | xz    | xz    -dc) ]] || exit 1
-[[ "bar" = $(echo bar | $PIXZ | $PIXZ -dc) ]] || exit 1
+[ "foo" = "$(echo foo | xz    | xz    -dc)" ] || exit 1
+[ "bar" = "$(echo bar | $PIXZ | $PIXZ -dc)" ] || exit 1