i've gotten my simple app working with lots of help from those here. many thanks for that! now i have a more theoretical question with regard to optimizing things. i have a series of variables gathered from a text file. they are then combined into a string and fed to a system() command so they can be passed to a command line app as its parameters. [code] string app_param = variable1 + variable2 + variable3 + variable4; system(app app_param); [/code] right now i am combining all of the variables into the string. in some instances, though, a variable is null or has a value of 0. what is a good way of excluding these from the string? [code] string app_param = variable1 + variable4; system(app app_param); [/code] thanks, BabaG

Well, I'd probably just do something like string app_param; if (variable1) app_param += " " + variable1; Or something to that effect.

By the way, don't be too concerned with optimization at this point: the system() call will use up far more CPU time and disk accesses than all of the string operations you do in preparing the command line.