Use $(COMMAND) instead of `COMMAND`

The usage of $(COMMAND) shoud be preferred. Details can be
found at http://mywiki.wooledge.org/BashFAQ/082.

Also replaced two ` used in strings with '.

Change-Id: Ia729470c58da6fe2e505426bd5ce93214ec1f655

run_tests.sh

@@ -128,15 +128,15 @@ function run_tests {
 
   # Just run the test suites in current environment
   set +e
-  testrargs=`echo "$testrargs" | sed -e's/^\s*\(.*\)\s*$/\1/'`
+  testrargs=$(echo "$testrargs" | sed -e's/^\s*\(.*\)\s*$/\1/')
   TESTRTESTS="$TESTRTESTS --testr-args='--subunit $testropts $testrargs'"
-  OS_TEST_PATH=`echo $testrargs|grep -o 'mistral\.tests[^[:space:]:]*\+'|tr . /`
+  OS_TEST_PATH=$(echo $testrargs|grep -o 'mistral\.tests[^[:space:]:]*\+'|tr . /)
   if [ -d "$OS_TEST_PATH" ]; then
       wrapper="OS_TEST_PATH=$OS_TEST_PATH $wrapper"
   elif [ -d "$(dirname $OS_TEST_PATH)" ]; then
       wrapper="OS_TEST_PATH=$(dirname $OS_TEST_PATH) $wrapper"
   fi
-  echo "Running \`${wrapper} $TESTRTESTS\`"
+  echo "Running ${wrapper} $TESTRTESTS"
   bash -c "${wrapper} $TESTRTESTS | ${wrapper} subunit2pyunit"
   RESULT=$?
   set -e
@@ -154,7 +154,7 @@ function run_tests {
 }
 
 function copy_subunit_log {
-  LOGNAME=`cat .testrepository/next-stream`
+  LOGNAME=$(cat .testrepository/next-stream)
   LOGNAME=$(($LOGNAME - 1))
   LOGNAME=".testrepository/${LOGNAME}"
   cp $LOGNAME subunit.log

tools/config/check_uptodate.sh

@@ -12,7 +12,7 @@ else
     exit 1
 fi
 
-TEMPDIR=`mktemp -d /tmp/${PROJECT_NAME}.XXXXXX`
+TEMPDIR=$(mktemp -d /tmp/${PROJECT_NAME}.XXXXXX)
 trap "rm -rf $TEMPDIR" EXIT
 
 tools/config/generate_sample.sh -b ./ -p ${PROJECT_NAME} -o ${TEMPDIR}

tools/config/generate_sample.sh

@@ -11,7 +11,7 @@
 # MISTRAL_CONFIG_GENERATOR_EXCLUDED_FILES: list of files to remove from automatic listing.
 
 print_hint() {
-    echo "Try \`${0##*/} --help' for more information." >&2
+    echo "Try '${0##*/} --help' for more information." >&2
 }
 
 PARSED_OPTIONS=$(getopt -n "${0##*/}" -o hb:p:m:l:o: \
@@ -37,17 +37,17 @@ while true; do
             ;;
         -b|--base-dir)
             shift
-            BASEDIR=`echo $1 | sed -e 's/\/*$//g'`
+            BASEDIR=$(echo $1 | sed -e 's/\/*$//g')
             shift
             ;;
         -p|--package-name)
             shift
-            PACKAGENAME=`echo $1`
+            PACKAGENAME=$(echo $1)
             shift
             ;;
         -o|--output-dir)
             shift
-            OUTPUTDIR=`echo $1 | sed -e 's/\/*$//g'`
+            OUTPUTDIR=$(echo $1 | sed -e 's/\/*$//g')
             shift
             ;;
         -m|--module)
@@ -66,7 +66,7 @@ while true; do
     esac
 done
 
-BASEDIR=${BASEDIR:-`pwd`}
+BASEDIR=${BASEDIR:-$(pwd)}
 if ! [ -d $BASEDIR ]
 then
     echo "${0##*/}: missing project base directory" >&2 ; print_hint ; exit 1
@@ -90,16 +90,16 @@ then
     OUTPUTDIR=$OUTPUTDIR/$PACKAGENAME
 elif ! [ -d $OUTPUTDIR ]
 then
-    echo "${0##*/}: cannot access \`$OUTPUTDIR': No such file or directory" >&2
+    echo "${0##*/}: cannot access '$OUTPUTDIR': No such file or directory" >&2
     exit 1
 fi
 
-BASEDIRESC=`echo $BASEDIR | sed -e 's/\//\\\\\//g'`
+BASEDIRESC=$(echo $BASEDIR | sed -e 's/\//\\\\\//g')
 find $TARGETDIR -type f -name "*.pyc" -delete
 FILES=$(find $TARGETDIR -type f -name "*.py" ! -path "*/tests/*" \
         -exec grep -l "Opt(" {} + | sed -e "s/^$BASEDIRESC\///g" | sort -u)
 
-RC_FILE="`dirname $0`/oslo.config.generator.rc"
+RC_FILE="$(dirname $0)/oslo.config.generator.rc"
 if test -r "$RC_FILE"
 then
     source "$RC_FILE"