#!/bin/sh

#
# sign_gen.sh - powerful signature generator
#
# (c) 2001-2002 Ondrej Jombik <nepto@pobox.sk>
# - based on the characters created by Rider <rider@lonestar.sk>
#
# $Id: sign-gen.sh,v 1.8 2002/04/12 17:33:02 jombik9 Exp $
#
# Updates: [14/4/2001] [3/10/2001] [7/11/2001]
#   12/4/2002 - execution code signature support
#             - multi user support via hashfile
#

#
# Directory of sign scripts (this one and cooperates scripts)
#
SIGN_DIR="$HOME/prog/scripts/sign"

#
# Hash file
#
SIGN_HASH_FILE="$SIGN_DIR/hash.cfg"

#
# Full path and file name of signature database file.
#
SIGN_DB_FILE="$SIGN_DIR/data/default.sign"

#
# Signature file separator. This string separate various signatures.  It
# must be alone on the line without any characters before or after string.
#
SIGN_DB_SEPARATOR="~~"

#
# Not used signature file separator. The same as parameter above, but this
# signature will be never used. This allows you to specify deprecated
# signatures without removing them from DB file.
#
SIGN_DB_SEPARATOR_NOTUSED="~~!!"

#
# Signature update delay time in seconds.
#
SIGN_DELAY=55

#
# Number of characters to indent header.
#
SIGN_INDENT_HEADER_NO_CHARS=40

#
# Character to indent header.
#
SIGN_INDENT_HEADER_CHAR=" "

#############################################################################

#
# Locating DB file
#
if [ -f "$SIGN_HASH_FILE" ]; then
	
	function extract_hash_file() {
		local filename="`cat $SIGN_HASH_FILE \
			| sed -e 's/^[[:space:]]*//g' \
			| sed -e 's/[[:space:]]*$//g' \
			| grep -v '^#' \
			| grep -i \"^$1:$2:\" \
			| cut -d: -f3 \
			| head -n1`";

		eval echo "$filename";
	}

	tmp_sign_db_file="`extract_hash_file \"\`id -un\`\" \"\`uname -n\`\"`";

	# If not found, try empty hostname
	if [ "x" = "x$tmp_sign_db_file" -o ! -f "$tmp_sign_db_file" ]; then
		tmp_sign_db_file="`extract_hash_file \"\`id -un\`\" \"\"`";
	fi

	# If still not found, try empty username
	if [ "x" = "x$tmp_sign_db_file" -o ! -f "$tmp_sign_db_file" ]; then
		tmp_sign_db_file="`extract_hash_file \"\" \"\`uname -n\`\"`";
	fi

	# If still not found, try empty hostname and username
	if [ "x" = "x$tmp_sign_db_file" -o ! -f "$tmp_sign_db_file" ]; then
		tmp_sign_db_file="`extract_hash_file \"\" \"\"`";
	fi

	if [ "x" != "x$tmp_sign_db_file" -a -f "$tmp_sign_db_file" ]; then
		SIGN_DB_FILE="$tmp_sign_db_file";
	fi
fi

#
# Testing if DB file exists
#
if [ -f "$SIGN_DB_FILE" ]; then
	echo "sign_gen.sh: using signature DB file '$SIGN_DB_FILE'";
else
	echo "sign_gen.sh: signature DB file '$SIGN_DB_FILE' not exists";
	exit;
fi   


#
# Creating indent header string
#
SIGN_INDENT_HEADER_STR="";
while [ $SIGN_INDENT_HEADER_NO_CHARS -gt 0 ]; do
	SIGN_INDENT_HEADER_STR="$SIGN_INDENT_HEADER_STR$SIGN_INDENT_HEADER_CHAR";
	SIGN_INDENT_HEADER_NO_CHARS=$(($SIGN_INDENT_HEADER_NO_CHARS-1));
done

#
# Creating server name (with uppercasing first character)
#
SIGN_SERVER_NAME=`uname -n \
	| perl -pe 's/^([^\.]*)\..*/$1/; s/^(.)/uc $1/e if not /[[:upper:]]/;'`;

#
# This is the same job as command above.
# (c) Rajo
#
if [ 0 -eq 1 ]; then
	uname -n | awk ' \
		function capitalize(str) { \
			if (str !~ tolower(str)) { \
				printf("%s",str) \ 
			} \
			else { \ 
				printf("%.1s%s", toupper(str), substr(str,2,length(str))) \
			} \
		} \
		BEGIN { FS = "." } \
		{ capitalize($1) } ' > /dev/null;
fi

#
# Main loop
#
while [ `ps x | sed 's/^ *//' | cut -f1 -d" " | grep "^$PPID$"` ]; do

	#
	# Fast check if signature file is still present; if not exit immidiately
	#
	if [ ! -f "$SIGN_DB_FILE" ]; then
		exit;
	fi

	#
	# Preparing some variabiles for date file
	#
	case `date +%m` in
		01) month="januar";;
		02) month="februar";;
		03) month="marec";;
		04) month="april";;
		05) month="maj";;
		06) month="jun";;
		07) month="jul";;
		08) month="august";;
		09) month="september";;
		10) month="oktober";;
		11) month="november";;
		12) month="december";;
	esac

	case `date +%w` in
		1) day="pondelok";;
		2) day="utorok";;
		3) day="streda";;
		4) day="stvrtok";;
		5) day="piatok";;
		6) day="sobota";;
		0) day="nedela";;
	esac

	#
	# Compose the date file
	#
	echo -e "$SIGN_INDENT_HEADER_STR$SIGN_SERVER_NAME, `date +%T`" \
		> ~/.tmp.d;
	echo -e "$SIGN_INDENT_HEADER_STR`date +%d`. $month `date +%Y` ($day)" \
		>> ~/.tmp.d;

	#
	# Preparing some variabiles for date file
	#
	sign_count=`cat $SIGN_DB_FILE | egrep "^$SIGN_DB_SEPARATOR$" \
		| wc -l | perl -pe 's/^\D*(\d)*$/$1/g;' 2>/dev/null`;
	sign_id=$RANDOM;
	sign_id=$(($sign_id%$(($sign_count+1))));

	#
	# Compose
	#   - the down signature file on stderr
	#   - the whole database file on stdout
	#
	# echo -e "----\nid - $sign_id\ncount - $sign_count" >> ~/.tmp.s;
	cat $SIGN_DB_FILE | perl -e " \
		my \$count; \$count = 0; \
		my \$ok; \$ok = 1; \
		while(<>) { \
			if (\$_ =~ /^$SIGN_DB_SEPARATOR_NOTUSED\$/) { \$ok = 0; next; } \
			if (\$_ =~ /^$SIGN_DB_SEPARATOR\$/) { \$ok = 1; \$count++; next; } \
			if (\$ok == 1) { \
				\$_ = eval(\$_) if (\$_ =~ '^\`'); \
				print stderr if (\$count == $sign_id); \
				print stdout; \
			} \
		}" 2> ~/.tmp.s > ~/.tmp.s.db;

	#
	# Compose whole database file (without separating tags)
	# TODO: only valid signatures should be witten into file
	#
	#cat $SIGN_DB_FILE \
	#	| egrep -v "^($SIGN_DB_SEPARATOR|$SIGN_DB_SEPARATOR_NOTUSED)$" \
	#	> ~/.tmp.s.db

	#
	# Compose whole signature
	#
	cat ~/.tmp.d > ~/.tmp.signature;
	echo "" >> ~/.tmp.signature;
	cat ~/.tmp.s >> ~/.tmp.signature;

	#
	# And now make some real job
	#
	mv -f ~/.tmp.d ~/.d;
	mv -f ~/.tmp.s ~/.s;
	mv -f ~/.tmp.s.db ~/.s.db;
	mv -f ~/.tmp.signature ~/.signature;

	#
	# Sleeping for a while
	# TODO: check child process in loop and abort when it terminates
	#
	sleep $SIGN_DELAY;

done