Allow updating headers in add-file-headers.sh

* Ignore changing amount of white space (avoids adding headers to files which do not have leading whitespace on empty line)
* add update option which allows to update any string in the first four lines of a header

add-file-headers.sh

@@ -4,20 +4,23 @@
 # Helper script to add headers to source files.
 # Invoke without arguments to display usage.
 #
-# date:   2018-19-01
+# date:   2019-14-03
 # author: Mat Hansen <mhansen@eclipsesource.com>
+# author: Johannes Faltermeier <mhansen@eclipsesource.com>
 #
 
 MODE="undefined"
 HEADER_FILE="LICENSE"
 SRC_PATH="/dev/null"
 INDENT=2 # two spaces 
+REPLACEMENT="undefined"
 
 declare -a EXT_LIST=(ts:c tsx:c)
 
 function print_usage {
-  show_status usage "$0 [all|git-dirty] [-h|--header=/path/to/header] [-p|--path=/path/to/src]"
+  show_status usage "$0 [all|git-dirty] [-h|--header=/path/to/header] [-p|--path=/path/to/src] [-u|--update=\"toreplace/replacement\"]"
   show_status usage "Example: $0 all --header=./LICENSE --path=/lib # Will add header from LICENSE file and it to all supported file types in /lib directory"
+  show_status usage "Example: $0 all --header=./LICENSE --path=/lib --update=\"2018 /2018-2019 \" # replace \"2018 \" with \"2018-2019 \" in existing headers"
 }
 
 function show_status {
@@ -60,6 +63,7 @@ function add_header {
   indent=$(printf ' %.0s' $(seq 0 $(($2-1))))
   header=$3
   file=$4
+  replace=${@:5}
 
   tmp_header=.~$style-style.header.tmp
 
@@ -68,8 +72,8 @@ function add_header {
       if [ ! -f $tmp_header ]; then 
         cat $header | sed -e 's/^\(.*\)/  \1/g; 1 s#^\(.*\)$#/*\n\1#; $ s#^\(.*\)$#\1\n*/#;' > $tmp_header
       fi
-      # check whether the first 3 lines are the same
-      if [ $(diff -q <(head -n 3 $tmp_header) <(head -n 3 $file) | grep differ | wc -l) -eq 1 ]; then
+      # check whether the first 3 lines are the same. ignore whitespace amount
+      if [ $(diff -qb <(head -n 3 $tmp_header) <(head -n 3 $file) | grep differ | wc -l) -eq 1 ]; then
 	cat $tmp_header > $file.new
 	cat $file >> $file.new
 	mv $file.new $file
@@ -80,6 +84,16 @@ function add_header {
       show_status error "Unsupported header style '$1'"
       exit 1
   esac
+
+  if [ "$replace" != "undefined" ]; then
+    # XXX: trailing spaces cut off
+    if [[ $replace == *" /"* ]]; then
+      replace="$replace "
+    fi
+
+    # replace in first 4 lines
+    bash -c "sed -i '1,4 s/$replace/g' $file"
+  fi
 
 }
 
@@ -98,6 +112,9 @@ while [ $# -gt 0 ]; do
     -p=*|--path=*)
       SRC_PATH="${1#*=}"
       ;;
+    -u=*|--update=*)
+      REPLACEMENT="${1#*=}"
+      ;;
     *)
       fail_arg "Invalid argument '$1'. Forgot the '=' sign or trailing spaces?"
       print_usage
@@ -119,11 +136,11 @@ do
   show_status info "Searching for $ext files... (applying $style style headers)"  
   case "$MODE" in
     all)
-      find $SRC_PATH -name "*.$ext" -exec bash -c 'add_header $0 $1 $2 "$3" $4' $style $INDENT $HEADER_FILE {} \;
+      find $SRC_PATH -name "*.$ext" -exec bash -c 'add_header $0 $1 $2 "$3" $4 $5' $style $INDENT $HEADER_FILE {} $REPLACEMENT \;
     ;;
     git-dirty)
       for file in $(git ls-files --others --exclude-standard --modified $SRC_PATH/**/*.$ext); do
-	add_header $style $INDENT $HEADER_FILE $file	
+	add_header $style $INDENT $HEADER_FILE $file $REPLACEMENT
       done
     ;;
   esac