Allocatable Character Variables In Fortran
Answer : This character (len=:), allocatable :: input_trim is certainly syntactically correct in Fortran 2003. You don't say what the error that gfortran raises is, so I can't comment on why it doesn't accept the line -- perhaps you have an old version of the compiler installed. With an up-to-date Fortran compiler ( eg Intel Fortran v14.xxx) you don't need to allocate the character variable's size prior to assigning to it, you can simply write input_trim = trim(input) Note that read(*,*) input_trim won't work.