#!/bin/bash

PAR=$1

let PAR=PAR%26

#ted osetrit desifrovani, provadeny zapornym parametrem.
if [PAR -lt 0] then let PAR=PAR+26

# Jestli je PAR 0, tak proste preposleme stdin na stdout
if [ "$PAR" -eq "0" ]; then
    cat
    exit
fi;

#velky pismena
LEVY_VELKY=$(echo -ne "\x$(printf "%02x" "$[65 + PAR]")")
PRAVY_VELKY=$(echo -ne "\x$(printf "%02x" "$[64 + PAR]")")

# maly pismena
LEVY_MALY=$(echo -ne "\x$(printf "%02x" "$[97 + PAR]")")
PRAVY_MALY=$(echo -ne "\x$(printf "%02x" "$[96 + PAR]")")

# Samotna transliterace
tr "[A-Z][a-z]" "[$LEVY_VELKY-ZA-$PRAVY_VELKY][$LEVY_MALY-za-$PRAVY_MALY]"