How to solve this - input/output keyword is invalid

[Ajain_A_]

Hello All,

can some somebody help me what is the following bug 

error:  #6640: This input/output keyword is invalid.

error #6332: A UNIT= specifier is required for this I/O operation.

#ifdef CONM2_OUT
   tempstr = './output/CS.conm2_', iloop
   call mg1g12conm2(CS_ID, tempstr)
#endif

[mecej4]

Post the actual code that caused the error message. There are no recognizable I/O statements in the fragment posted, but it is hard to tell without seeing the relevant variable and type declarations. The statement [fortran]tempstr = './output/CS.conm2_', iloop[/fortran] appears suspicious. What is it supposed to do? Perhaps, [fortran]write(tempstr,'(A,I0)')'./output/CS.conm2_', iloop[/fortran] is what was intended?

[lklawrie]

Well, you've only shown a brief excerpt of your code. As mecej4 says -- the tempstr assignment appears strange, not valid. (I0 is probably not correct in his reply, but otherwise, it is right on track)

[mecej4]

I0 is probably not correct in his reply

Linda, The specification of a zero field width is allowed. It helps produce a minimal length string of digits (no leading blanks or zeros) from an integer. Section 10.7.2.1, Rule (2) of the Fortran 2008 standard says

(6) On output, with I, B, O, Z, F, and G editing, the specified value of the field width w may be zero. In such cases, the processor selects the smallest positive actual field width that does not result in a field filled with asterisks.