add timestamp sourcing script

add-timestamp-to-howtocard.sh

+#!/bin/sh
+
+# change this with environment
+DEFAULT_NOT_SOURCE_REGEX="/\\/assets\\//"
+NOT_SOURCE_REGEX="${NOT_SOURCE_REGEX:-$DEFAULT_NOT_SOURCE_REGEX}"
+TIMESTAMP_SUFFIX="${SUFFIX:-.timestamp}"
+LOGFILE="${LOGFILE:-/dev/null}"
+
+[ -z "$1" ] && echo "$0: no inputs specified?" >/dev/stderr
+
+while [ -n "$1" ]
+do
+	echo "sourcing directory '$1' ..." >> "$LOGFILE"
+	find "$1" -type f -name '*.md' | grep -v "$NOT_SOURCE_REGEX" | while read file ; do
+		fn=`basename "$file"`
+		dir=`dirname "$file"`
+		tsfn="$fn.timestamp"
+		(
+			echo "making timestamp in '$dir' for file '$fn' ..." >> "$LOGFILE"
+			cd "$dir"
+			if [ -f "$tsfn" ]
+			then echo "... but it already exists; skipping!" >> "$LOGFILE"
+			else
+				TIMESTAMP=`git log -n 1 --pretty=format:%cs -- "$fn"`
+				mv "$fn" "$fn.temporary"
+				head -n1 "$fn.temporary" > "$fn"
+				echo "timestamp: \"$TIMESTAMP\"" >> "$fn"
+				tail -n+2 "$fn.temporary" >> "$fn"
+				rm -f "$fn.temporary"
+			fi
+		)
+	done
+	shift
+done