exchange two words using sed in Linux

Question

guys! I am trying to exchange two words in a line but it doesn\'t work. For example: \"Today is my first day of university\" should be \"my is Today first day of university\"

Answer 1

sed -r 's/^(\w+)(\s+\w+\s+)(\w+)(.*)/\3\2\1\4/'

with your example:

kent$  echo "Today is my first day of university"|sed -r 's/^(\w+)(\s+\w+\s+)(\w+)(.*)/\3\2\1\4/'                                                                           
my is Today first day of university

for your problem, awk is more straightforward:

awk '{t=$1;$1=$3;$3=t}1'

same input:

kent$  echo "Today is my first day of university"|awk '{t=$1;$1=$3;$3=t}1'                       
my is Today first day of university