For example, when I entered either:
gcc -O hello.c -c
Or
gcc hello.c -c -O
Both did not complain.
Does the order of command options matter?
Linux – Does the order of command options in linux matter
command linelinuxordering
Related Solutions
The order that they're stored/returned in the filesystem. For "unsorted" filesystems this would generally be their creation order. For "sorted" filesystems (e.g. ext3/4 with dir_index) this would be the order used in the filesystem index.
What you are asking for is almost certainly impossible. Command line arguments are passed to a program at launch. Once it has loaded, any settings changed will be in effect but you cannot pass any more arguments.
When you run vlc --whatever it will attempt to launch another instance of vlc which will load with the option --whatever set. If you have "allow only one instance" set in your vlc preferences, this will have no effect and it will look like "vlc does not complain". You might be able to get this sort of behavior from the VideoLanServer but I have never used it and do not know. You will not get this from any "normal" program that is not running in some kind of server or listening mode.
A better question is why would you need this behavior? If you are displaying vlc output normally, you can just use the hotkeys normally as long as the vlc window has the mouse focus. Even if you don't and you are, for example, watching vlc in a terminal over an ssh connection to a headless server using its ASCII art output modes, the hotkeys work as long as the terminal with the ssh has focus. Are you trying to somehow script this behavior? Could this be an XY problem?
Best Answer
This depends on the program itself; the operating system doesn't dictate whether or not order matters.
GCC's set of options is so colossal that I can't say with any authority if you can supply any option in arbitrary order; you'll have to read the documentation for that option. That said, a general rule of thumb is that if you have two or more mutually exclusive options (such as
-O1 -O2for differing levels of optimisation), programs will generally take later options over earlier ones. Again, this isn't enforced by linux.A simple program that does let you specify most options in any order would be
ls. Listing all files in the current directory with detail can be done with eitherls -la,ls -alorls -l -a. However, ls -l1 (that is 'el' 'one') does not give the same output as ls -1l ('one' 'l'). These are mutually exclusive options, and the last listed over rides the first given.There is also the odd program which applies options to arguments as they arrive. So, for example, you might have a hypothetical command
blah -a 1 2 -b 3where-aapplies to all three arguments, but-bonly applies to3.Again, this is up to the individual program in question. If you're ever unsure, read the documentation.