#!/bin/bash
#
# The most valuable link
# http://abs.traduc.org/
#
# written by
# Pierre-Emmanuel Périllon
#
# date
# 18-07-2007
#
# licence
# GPL-2
#
# encoding
# UTF8
#
# it may work with
# GNU bash, version 3.1.17(1)-release (i486-pc-linux-gnu)
# Copyright © 2005 Free Software Foundation, Inc.
#
# purpose
# this script concats a given file a to another file b and puts the result
# in b. So that, the first file become the header of b.
# it protects itself and the "a" file against modification by testing
# inodes.
# it uses a tempory file named /tmp/add_header
# be carefull, it has a recursive behavior.
#
# bugs
# * do not work properly if filename have a space
# * you have to escape the wilcard (\*) to prevent substitution cause bash
# will substitude soon he can.


################################################################################
# where is the tmp file, you may change it if you want... i assume /tmp has 666 permission
tmp='/tmp/add_header'

################################################################################
# verify and prepare the input

if [ -z $2 ]
then
echo
echo "usage:"
echo "$0 /pathname/of/header/to/add/to/files /directory/to/work/on [pattern with wildcad *]"
echo
echo "[] indicate an option"
echo
exit
fi

if [ -z "$3" ] #to protect against auto complete
then
allowed="*"
else
allowed="$3"
fi

head="$1"

work_on="$2"

################################################################################
# main part

# looking for file
#echo $work_on/$allowed

for file in `echo $work_on/$allowed`
do
if [ -f $file ]
then
if [ $file -ef $head ]
then
echo ':( - script may not modify given header file.'
elif [ $file -ef $0 ]
then
echo ':( - script may not modify itself.'
else
echo ':) - '$file
cat $head > $tmp
cat $file >> $tmp
cat $tmp > $file
fi
# else
# echo ':( - '$file
fi
done

#remove tempory file...
rm -f $tmp

#now looking for sub-directory
for directory in `echo $work_on/*`
do
if [ -d $directory ]
then
echo '>> - '$directory # is a directory, moving into'
$0 "$head" "$directory" "$3"
echo '<< - '$work_on # return to parent done
fi
done

#echo "done"