FIXED FIELD LENGTH is not constant

Hello Guru's,

This is the question asked in IBM .

What will you do if field length of a field in flat file is not constant or not equal to the FIXED FILED LENGTH ?.

i.e. f1 is of length is 10 and in one row its length is only 9 what will happen and what will you do to overcome this situation.( consider its a FILE TO FILE SCENARIO )

can anyone help me in this regard.

Thanks in advance.