3. Same Source, Same Output

The problem with command line switches selecting output option in case of low level assembly is that the given code will anyway most probably assemble and execute correctly only when the same output is selected that programmer had in mind when writing this code. Also I remembered many cases when I had a source for TASM written by someone other, and to compile it correctly I had to follow the directions given in the comment at the beginning of source and just rewrite all the command line switches as described there. And my though was: then why don't just make assembler look for such options in the source instead, so nobody will have any problem with recompiling. Thus came the SSSO principle - all the settings that can affect the output of assembler are be selected only from source and source is always enough to generate exactly the file which was intented by programmer. The consequence of SSSO idea was also that no matter what version of fasm (considering ports to different operating systems), it always generated the same output file, so when you have written a DOS program, the Linux version of fasm would still make the same DOS executable from such source.

Some people seem to dislike the implications of this principle, because all other assemblers and compilers have the command line settings that affect the output (or even the source constants) and this different approach needs to change a bit the way of thinking in some cases (this actually happens in even more areas when programming with flat assembler, and it's the purpose of this text to show the origin and reason for those differences). The SSSO rule became one of the guidelines for the design of flat assembler and I don't plan to put it away.

Design Principles or why flat assembler is different? wrote:

3. Same Source, Same Output

The problem with command line switches selecting output option in case of low level assembly is that the given code will anyway most probably assemble and execute correctly only when the same output is selected that programmer had in mind when writing this code ....

; test.asm
           [section .code]
           [global main]
main:
           push msg
           [extern puts]
           call puts
           push 0
           [extern exit]
           call exit


           [section .const]
msg db "I am a portable program.",13,10,0
    

You depend on the external standard
....
PS. And see source of fasm itself for a much more sophisticated example of how to assemble the same source for different OSes.

Anyways, tell me what does "PS" mean

just a single command line switch would have been a lot better.

The best thing about FASM is that you control everything from the source code.

You don't need external libraries,