C does not and never has had a native string type. By convention, the language uses arrays of char terminated with a null char, i.e., with ‘\0′. Functions and macros in the language’s standard libraries provide support for the null-terminated character arrays, e.g., strlen iterates over an array of char until it encounters a ‘\0’ … Read more
I wish to know which of these two options is the more secure one to use: sprintf(buff, “%.*s”, MAXLEN, name) snprintf(buff, MAXLEN, “%s”, name) My understanding is that both are same. Please suggest.
Allocated Array With an allocated array it’s straightforward enough to follow. Declare your array of pointers. Each element in this array points to a struct Test: Then allocate and assign the pointers to the structures however you want. Using a loop would be simple: Then declare a pointer to this array: This allows you to … Read more
In a C function, I want to check if an input argument (‘value’ in my case) is presented or not. i.e.: When used if(value != NULL) statement, my Console() function sends 4096 How can I check and act based on argument existence?
Given an arbitrary type (I’ve chosen char here, but that is for sake of concrete example): You can use either of these expressions: Leading to a malloc() call such as: The last version has some benefits in that if the type of ppc changes, the expression still allocates the correct space.
Yes – older POSIX standards defined usleep(), so this is available on Linux: DESCRIPTION The usleep() function suspends execution of the calling thread for (at least) usec microseconds. The sleep may be lengthened slightly by any system activity or by the time spent processing the call or by the granularity of system timers. usleep() takes … Read more
Starting from Visual Studio 2017 (15.9.4) there is an option: The corresponding fragment from the Visual Studio documentation: Automatically close the console when debugging stops: Tells Visual Studio to close the console at the end of a debugging session.
The key is in this: previous implicit declaration of ‘point_forward’ was here On line 96 you have: Since the compiler hasn’t yet seen a function declaration for point_forward(m), it “implicitly defines” (ie, assumes) a function that returns an int: This conflicts with the definition later: To fix this, you can either: Put an explicit declaration somewhere before line … Read more
I recommend @Jens Gustedt hexadecimal solution: use %a. OP wants “print with maximum precision (or at least to the most significant decimal)”. A simple example would be to print one seventh as in: But let’s dig deeper … Mathematically, the answer is “0.142857 142857 142857 …”, but we are using finite precision floating point numbers. … Read more
Simple math: log2 (x) = logy (x) / logy (2) where y can be anything, which for standard log functions is either 10 or e.