#!/bin/bash
echo "WORD1 %WORD2% WORD3 some text WORD1 %WORD2% WORD3" |
sed 's/WORD1/й/g' |
sed 's/WORD3/ч/g' |
sed 's/й[^йч]*ч/й ч/g' |
sed 's/й/WORD1/g' |
sed 's/ч/WORD3/g'
IyEvYmluL2Jhc2gKZWNobyAiV09SRDEgJVdPUkQyJSBXT1JEMyBzb21lIHRleHQgV09SRDEgJVdPUkQyJSBXT1JEMyIgfCAKICAgc2VkICdzL1dPUkQxL9C5L2cnIHwKICAgc2VkICdzL1dPUkQzL9GHL2cnIHwKICAgc2VkICdzL9C5W17QudGHXSrRhy/QuSDRhy9nJyB8CiAgIHNlZCAncy/QuS9XT1JEMS9nJyB8CiAgIHNlZCAncy/Rhy9XT1JEMy9nJyAKICAg