What can Tcl Script do ?

Hi everyone,

I've been using fpga for several month and everytime I use tcl script to assign pins. It seems that in addition to assign pins tcl script can do many things other than, such as:

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set_global_assignment -name RESERVE_ALL_UNUSED_PINS "AS INPUT TRI-STATED WITH WEAK PULL-UP"

set_global_assignment -name ENABLE_DEVICE_WIDE_RESET OFF

set_global_assignment -name ENABLE_INIT_DONE_OUTPUT OFF

--- Quote End ---

I want to know more use of tcl script.

Any informations are appreciated.

Thanks.