# ----------------------------------------------------------------------
#    Name:	replacehtml
# ----------------------------------------------------------------------
#    Author:	Dean Stringer (deeknow@pobox.com)

#    Desc:	Performs a FIND search starting from the directory
#		specified by the 1st argument (after checking if this
#		DIR actually exists) and looks for all *.?htm? files
#		that contain the string specified by the 2nd argument
#		adding their names to an index file specified by the
#		constant '$dirList'
#
#		Uses SED to do a search/replace on these files, based
#		on the 2nd and 3rd arguments.
#
#		The script first checks to see if the 1st paramater
#		is "UNDO" in which case it will return the previoulsy
#		modified files to their original state by 'mv'ing
#		the backup copy over the changed one.
#
#		It goes without saying (of course) that you will need
#		write privaledges to all directories and files that
#		match the search.
#
#
#	!!!! WARNING !!!!
#
#	you should check the results of the output from this
#	script before running it again, otherwise you will
#	not be able to do a subsequent UNDO.
#
# ----------------------------------------------------------------------



# ----------------------------------------------------------------------
# Set some constants
# ----------------------------------------------------------------------
backupSuffix="old~"	# suffix to use for backup of changed files
dirList="dirlist"	# file to contain DIR listing
seperator="------------------------------------------------------------------------"

# Get the 1st paramater
startDir=$1


# ----------------------------------------------------------------------
# Dont let the user run at web root level
# ----------------------------------------------------------------------
if [ "$startDir" = "/home/www/" -o "$startDir" = "/home/www" ] ; then
	echo "ERROR !!!   Cannot perform at root level"
	exit
fi


# ----------------------------------------------------------------------
# Save the last directory listing if there is one
# ----------------------------------------------------------------------
if [ -f $dirList ]; then
	cp $dirList $dirList.last
fi


# ----------------------------------------------------------------------
# Check there's at least three arguments
# ----------------------------------------------------------------------
if [ $# -ge 3 ] ; then
	str2find=$2
	str2replace=$3


	# Make sure the start directory exists
	if [ -d $startDir ]; then
		echo "Searching $startDir"

		# Find iall matching files and pipe out to directory file

		# set maxdepth to 1 (ie only process current DIR) unless $4 is set to "CRAWL"
		depth=$4
		if [ "$depth" = "CRAWL" ] ; then
			find $startDir -iregex ".*htm.?" -print0 | xargs -0 grep -l "$str2find" > $dirList
		else
			find $startDir -iregex ".*htm.?" -print0 -maxdepth 1 | xargs -0 grep -l "$str2find" > $dirList
		fi

		# Check no of files being replaced
		echo "Found `cat $dirList | wc -l` files that will be updated."

		# Save date/time and user name into history file
		echo -e "$seperator\n`whoami` ran DIRLIST on `date`" >> $dirList.history
		echo "Replacing: $str2find" >> $dirList.history
		echo "With:  $str2replace" >> $dirList.history
		cat $dirList >> $dirList.history
		echo "Total = `cat $dirList | wc -l` files" >> $dirList.history

		# Do a search/replace on each file in the index file
		for file in `cat $dirList` ; do
			cp $file $file.$backupSuffix
 			sed "s/$str2find/$str2replace/g" $file.$backupSuffix > $file
 		done
	else
		errorMessage="Start Directory does not exist"
	fi


# ----------------------------------------------------------------------
# Not enough arguments, check for other run-options
# ----------------------------------------------------------------------
else
	# Check to see if user wants to UNDO
	if [ "$startDir" = "UNDO" ] ; then

		# we ARE undoing, so check an old directory file exists
		if [ -s $dirList ]; then

			# It does, so restore each file in the index file
			echo -e "$seperator\n`whoami` ran a DIRLIST UNDO on `date`" >> $dirList.history
			echo "Performing an UNDO"
			for file in `cat $dirList` ; do
				mv $file.$backupSuffix $file
 			done
			mv $dirList $dirList.undo
		else
			# No directory file exists so can't undo
			errorMessage="Cannot UNDO, no '$dirList' found"
		fi
	else
		errorMessage="Wrong no. of Arguments"
	fi
fi


# ----------------------------------------------------------------------
# If there's an error message set, display it and the correct syntax
# ----------------------------------------------------------------------
if [ "$errorMessage" !=  "" ] ; then
	echo ''; echo "ERROR !!!  $errorMessage"
	echo ''; echo "Syntax is :   replacehtml <startdir> <strt2find> <str2replace>"
	echo "     or       replacehtml UNDO"
fi