TT#140851 reorder_tests_tt2.sh with usage() and new functionalities

Implemented usage() function inside reorder_tests_tt2.sh to describe how to use it.
Additionally, 2 new options have been implemented:
- -m git|mv : if set the renaming is performed with "mv" command rather than "git mv", useful if you are not on a git directory
- -t : just outputs the renaming to stdout without really renaming (dry run)

Change-Id: I0be8a2d6468b66d365ec138a09e5ac5873bf694f

bin/reorder_tests_tt2.sh

@@ -11,12 +11,63 @@ log_info()
   echo "INFO: $*"
 }
 
+function usage
+{
+  echo "Usage: reorder_tests_tt2.sh [-t] [-m git|mv] firstmessagenumber [displacement]"
+  echo "Options:"
+  echo -e "\th: this help"
+  echo -e "\tm [git|mv]: select whether to use 'git move' or 'mv' while renaming"
+  echo -e "\tt: dry run"
+  echo "Args:"
+  echo -e "\\tfirstmessagenumber: numer of the first testfile to be processed"
+  echo -e "\\tdisplacement: displacement to add to the test filename (optional, considering 1 if not given)"
+  echo
+  echo "Examples:"
+  echo -e "\\t\$ reorder_tests_tt2.sh 19 2"
+  echo -e "\\t will take each testfile of the current directory with filename number >= 19 ( for example 0024_test.yml.tt2) and add 2"
+  echo -e "\\t this script will rename the files like this:"
+  echo -e "\\t ./0024_test.yml.tt2 -> ./0026_test.yml.tt2"
+  echo -e "\\t ./0023_test.yml.tt2 -> ./0025_test.yml.tt2"
+  echo -e "\\t ./0022_test.yml.tt2 -> ./0024_test.yml.tt2 "
+  echo -e "\\t ... and so on until we reach ./0019_test.yml.tt2"
+  echo -e "\\t"
+  echo -e "\\t\$ reorder_tests_tt2.sh -m mv 19 2"
+  echo -e "\\t   this comand will do the same but it will use mv rather than git mv"
+  echo -e "\\t\$ reorder_tests_tt2.sh -t 19 2"
+  echo -e "\\t   this comand will do the same but it will just preview what will be renamed and how without changing anything"
+}
+
+DRY_RUN=0
+MODE="git"
+
+while getopts 'hm:t' opt; do
+  case $opt in
+    t) DRY_RUN=1;;
+	m) MODE=${OPTARG};;
+    *) usage; exit 1;;
+  esac
+done
+
+shift $((OPTIND - 1))
+
 INI=$1
 DISP=${2:-1}
 
 case $# in
 	1|2) ;;
-	*) echo "Wrong number or arguments"; usage; exit 1;;
+	*) echo "Wrong number or argument s $#"; usage; exit 1;;
+esac
+
+if [[ "$DRY_RUN" == 1 ]]; then
+	echo "Using dryrun"
+fi
+
+case "${MODE}" in
+  mv) echo "Using ${MODE} for renaming";;
+  git) MODE="git mv"; echo "Using ${MODE} for renaming";;
+  *) echo "Error: mode ${MODE} unknown"
+     usage
+     exit 2;;
 esac
 
 last_file=$(printf "%04d_test.yml.tt2" "${INI}")
@@ -34,8 +85,12 @@ find . -name '0*_test.yml.tt2' | sort -r | while read -r tfile ; do
 		if [ -f "${next_file}" ] ; then
 			die "file ${next_file} already exist"
 		fi
-		git mv "${tfile}" "${next_file}"
+		if [[ "$DRY_RUN" == 1 ]]; then
+			echo " rename ${tfile} into ${next_file}"
+		else
+			"${MODE}" "${tfile}" "${next_file}"
 			log_info "OK ${num} => $next"
+		fi
 	else
 		log_info "nothing to do with ${tfile}"
 	fi