Allow other checksum options

[mandresm]

At the moment imohash is the default and users cannot select another type of checksum. One should be able to have an option in the cli of the different checksums commands to switch to md5 for example

[siligam]

This feature of having a choice of selecting a desired hashing algorithm may or may not be a good idea.

When comparing 2 csv files, the tool needs to ensure if same type of hashing algorithm is used in producing these checksum files otherwise the results of comparing them will be garbage. This logic is not yet implemented as the tool offers only imohash.

For a given site and pool, the use may want to produce checksums using imohash and md5 , then the question is how to name the file. Following the naming convention checksum_<SITE>_<PROJECTNAME>.csv, they need to placed in separate directories. What should be the entry in config file in this case?

opting for slow md5 means that users are forced to submit the job to slum as running this task on the login node will occupy a lot of resources for a long time and might render unusable to other users. Most likely these jobs get killed by the admins without any prior notice.

Having said that, I wish to provide users have choice of choosing their desired algorithm.

[mandresm]

We've decided to don't allow md5 for remote-chesums but only for prepare-runscript