Shell Programming and Scripting

abc abc abc abc abc abc

echo "abc abc abc abc abc abc"|sed -e "s/abc abc/abc cba/g"
abc cba abc cba abc cba

  awk '{ for (i=1; i<=NF; i++)
           $i = i % 2 ? $i : "cba"
        }1'

perl -pe's/(\w+)/$c++%2?cba:$1/ge'

% print abc abc abc abc abc abc |
  awk '{ for (i=1; i<=NF; i++)      
           $i = i % 2 ? $i : "cba"
        }1'
abc cba abc cba abc cba
% print abc abc abc abc abc abc |
  perl -pe's/(\w+)/$c++%2?cba:$1/ge'
abc cba abc cba abc cba

echo 'abc abc abc abc abc abc'|
awk '{for(i=2;i<=NF;i+=2){$i="cba"}}1'

awk '{ 
  for (i=2; i<=NF; i+=2) 
    $i = "cba"
        }1'