I am relatively new to C and I need some help with methods dealing with arrays. Coming from Java programming, I am used to being able to say int [] method()in order to return an array. However, I have found out that with C you have to use pointers for arrays when you return them. … Read more
Closed. This question needs to be more focused. It is not currently accepting answers. Closed 4 years ago. Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. How can I check if a given number is even or … Read more
By considering that the memory is divided into four segments: data, heap, stack, and code, where do global variables, static variables, constant data types, local variables (defined and declared in functions), variables (in main function), pointers, and dynamically allocated space (using malloc and calloc) get stored in memory? I think they would be allocated as … Read more
OK, so I don’t sound like an idiot I’m going to state the problem/requirements more explicitly: Needle (pattern) and haystack (text to search) are both C-style null-terminated strings. No length information is provided; if needed, it must be computed. Function should return a pointer to the first match, or NULL if no match is found. … Read more
Is there a clean, preferably standard method of trimming leading and trailing whitespace from a string in C? I’d roll my own, but I would think this is a common problem with an equally common solution. 40 Answers 40 If you can modify the string: // Note: This function returns a pointer to a substring … Read more
I’m after some simple examples and best practices of how to use regular expressions in ANSI C. man regex.h does not provide that much help. 5 Answers 5
I just saw a picture today and think I’d appreciate explanations. So here is the picture: I found this confusing and wondered if such codes are ever practical. I googled the picture and found another picture in this reddit entry, and here is that picture: So this “reading spirally” is something valid? Is this how … Read more
I have a FILE *, returned by a call to fopen(). I need to get a file descriptor from it, to make calls like fsync(fd) on it. What’s the function to get a file descriptor from a file pointer? 3 Answers 3
Consider the following switch statement: switch( value ) { case 1: return 1; default: value++; // fall-through case 2: return value * 2; } This code compiles, but is it valid (= defined behavior) for C90/C99? I have never seen code where the default case is not the last case. EDIT: As Jon Cage and … Read more
