Use:
find . -name "*.t1" -exec bash -c 'mv "$1" "${1%.t1}".t2' - '{}' +
If you have rename
available then use one of these:
find . -name '*.t1' -exec rename .t1 .t2 {} +
find . -name "*.t1" -exec rename 's/\.t1$/.t2/' '{}' +
Use:
find . -name "*.t1" -exec bash -c 'mv "$1" "${1%.t1}".t2' - '{}' +
If you have rename
available then use one of these:
find . -name '*.t1' -exec rename .t1 .t2 {} +
find . -name "*.t1" -exec rename 's/\.t1$/.t2/' '{}' +