[CentOS] e2fsck run under "read only mode"???

Thu Mar 22 15:17:02 UTC 2012
mcclnx mcc <mcclnx at yahoo.com.tw>

We have CENTOS 5.5 run on DELL server.   Due to power system crash, server been down and up.
I would like use 'e2fsck" to check file systems.

Does there has way to run "e2fsck" under following conditions:

1. file systems are all ext3

2. file systems must mount.

3. e2fsck only scan file system but NO modify


Thanks.