On 10 May 2011 07:47, ali hagigat wrote: > Suppose we have the following command: > > gcc -IDIR prog1.c -o prog1 > > Suppose DIR is the system directory as well. So -I is ignored, does it mean?!!: > > gcc DIR prog1.c -o prog1 Of course it doesn't mean that. That would be an invalid command. If you type that command it would give an error. But if you use -IDIR where DIR is a system directory, it doesn't give an error. It's not difficult. > or it means?: > gcc prog1.c -o prog1 Yes. Why don't you just try it and find out how it works? > None of them is true I think. Using -I has an effect in the compiling > of prog1.c and this effect is not ignored and is considered before > prog1.c. What makes you think that? > When the manual says -I is ignored, it means that, it is like that -I > does not exist and has never been used. Yes, that is what it means. > But in fact the effect of -I has been changed. I think that -I is > ignored seems not a good word, it can be replaced with "the effect of > -I changes..." How does it change?
