has quotation marks, then by default cmd will in some cases strip off those quotes, and /s tells it to depart them alone.
Using %s in scanf with no an explcit industry width opens a similar buffer overflow exploit that will get did; namely, if you'll find extra people during the input stream when compared to the goal buffer is sized to hold, scanf will happily publish Those people additional characters to memory outdoors the buffer, perhaps clobbering a little something important. Sadly, not like in printf, You cannot offer the field with like a run time argument:
But it really doesn't do any harm, and this means the code would however operate the same way It doesn't matter how the command being handed was changed.
* Results in fprintf to pad the output until finally it is actually n people wide, the place n is really an integer worth saved from the a functionality argument just previous that represented with the modified sort.
This is particularly crucial for users of our Neighborhood who will be rookies, and not informed about the syntax. On condition that, are you able to edit your respond to to include a proof of what you're accomplishing and why you think it is the greatest tactic?
The difference lies in the best way it get's managed. In the event you might have a group of (for example) 3 Areas immediately next each other s+ can take that team and turns the whole it into a "", when s would proces each and every Place By itself.
That way it could stand on its own. Furnishing an case in point that was comparable to the example during the problem would also be a in addition.
The 1st just one matches an individual whitespace, whereas the next one matches a single or numerous whitespaces. They're the so-named typical expression quantifiers, plus they execute matches like this (taken from your documentation):
All machine dependent code is penned in assembly language.The assembly language is different for various processors.
How come critical signatures swap from flats to sharps at a specific method brightness? additional warm questions
This executes SomeCommand.exe redirecting common output to a temp file and common mistake to the same spot:
The kernel does not have the posh of your libc library to deal with the Preliminary create of varied means.
Therefore the arguments envisioned s by C, ought to be hacked up via the C runtime library. The functioning system only materials one string with the arguments in, and Should your language just isn't C (and even whether it is) it will not be interpreted as Area-divided arguments quoted As outlined by shell regulations, but as a thing totally unique.
So In case you have an advanced command which you would like to move to CMD.exe you either have to recollect CMD's argument quoting regulations, and properly escape each of the prices, or use /S, which triggers a Distinctive non-parsing rule of "Strip first and last " and deal with all other characters as the command to execute unchanged".
This is probably extra prone to be attractive from the situation during the concern Michael Burr associated with, the place cmd.exe is becoming introduced by CreateProcess rather than from the batch file or maybe the command line itself..
The PEP would not say "supplanted" As well as in no part of the PEP will it say the % operator is deprecated (nonetheless it does say other things are deprecated down The underside). You might prefer str.structure and that is wonderful, but right up until there's a PEP saying it's deprecated there is not any feeling in professing it really is when it isn't.