Ok, what we have here is a chunk of really poorly written code. What I will do in this post could best be described as software archaeology. Step 1: fix the formatting. The indention and compact format doesn’t do anyone any good. Various spaces and empty rows need to be inserted. The comments could be … Read more
There is no good example of register usage when using modern compilers (read: last 15+ years, and note that this answer is from 2008) because it almost never does any good and can do some bad. When you use register, you are telling the compiler “I know how to optimize my code better than you … Read more
By default, macOS (formerly OS X and Mac OS X) software recognizes EOF when Control-D is pressed at the beginning of a line. (I believe this behavior is similar for other versions of Unix as well.) In detail, the actual operation is that, when Control-D is pressed, all bytes in the terminal’s input buffer are … Read more
The problem is that getline() is a standard library function. (defined in stdio.h) Your function has the same name and is thus clashing with it. The solution is to simply change the name.
Recall how string literals work in C – “\0” is a character array containing two zero bytes (the one you asked for, and the implicit one at the end). When evaluated for the if test, it decays into a pointer to its first character. This pointer is not NULL, so it’s considered true when used … Read more
To enter an EOF, use: ^Z (CtrlZ) in Windows ^D on Unix-like systems
It’s called Bootstrapping, quoting from Wikipedia: If one needs a compiler for language X to obtain a compiler for language X (which is written in language X), how did the first compiler get written? Possible methods to solving this chicken or the egg problem include: Implementing an interpreter or compiler for language X in language … Read more
The question you are asking is really two questions, not one. Most replies so far tried to cover the entire thing with a generic blanket “this is K&R style” answer, while in fact only a small part of it has anything to do with what is known as K&R style (unless you see the entire … Read more
One thing to be aware of when you’re using the token-paste (‘##‘) or stringizing (‘#‘) preprocessing operators is that you have to use an extra level of indirection for them to work properly in all cases. If you don’t do this and the items passed to the token-pasting operator are macros themselves, you’ll get results … Read more