+
+ if ! $new_file; then
+ if [[ ! -r $file ]]; then
+ echo "appendu error: cannot read or write $file"
+ return 1
+ fi
+ if [[ ! -w $file ]]; then
+ echo "appendu error: cannot read or write $file"
+ return 1
+ fi
+ # fix files with no newline at the end.
+ # the following command won't work right on them otherwise.
+ # e = run script, $a\ means append following text, but there is none,
+ # so sed only does what it always does when it was supposed to modify a file,
+ # which is append a newline if there was none.
+ sed -ie '$a\' "$file"
+ # command substitution removes any trailing newlines, so we have to add
+ # a non-newline ending, we randomly chose "b", then remove it.
+ local content=$(cat "$file"; echo b) content=${content%b}
+ fi
+
+ # we aren't using regex because we want to match strings,
+ # but we also want our match to start at the beginning of a line,
+ # or the beginning of the file, and to end at a line ending.
+ # So we do some slick bash to match this.
+ local start="?(*
+)"
+ local end="
+*"
+ local return_code string return_code
+ for string in "${strings[@]}"; do
+ if $new_file || [[ $content != $start"$string"$end ]]; then
+ if ! tee -a "$file"<<<"$string"; then
+ return_code=$?
+ echo "appendu error: error writing to $file"
+ return $return_code
+ fi
+ fi
+ done
+ return 0