Hi, I looked around in some forums, but couldn't find a good answer to this problem: my programmes produce several output files. When the programm is finished, I add certain simulation parameters to the file name, so that I see later, to which simulation run this file belongs. (for example, a file "result.dat" is renamed to "result_500.dat" because the 500 is a certain parameter in that programm). Now i don't want to manually rename a lot of files, but instead I'm looking for a way to make Fortran incorporate certain variables in the file names. I only know this way of declaration: Code (Text): open(unit=1,status='unknown',file='result.dat') Assuming I have a certain variable (e.g. an integer called "number") Is it possible to assign a file name "result_*number*.dat", so that I only have to change the value of "number" and all files have that in their names? Thanks for your help.