Get a substring of a char* [duplicate]
Job done 🙂
c
What does “dereferencing” a pointer mean?
Reviewing the basic terminology It’s usually good enough – unless you’re programming assembly – to envisage a pointer containing a numeric memory address, with 1 referring to the second byte in the process’s memory, 2 the third, 3 the fourth and so on…. What happened to 0 and the first byte? Well, we’ll get to … Read more
What is an unsigned char?
In C++, there are three distinct character types: char signed char unsigned char If you are using character types for text, use the unqualified char: it is the type of character literals like ‘a’ or ‘0’ (in C++ only, in C their type is int) it is the type that makes up C strings like … Read more
What is the difference between C and embedded C?
Can any body tell me the differences between them?
How to convert a string to integer in C?
There is strtol which is better IMO. Also I have taken a liking in strtonum, so use it if you have it (but remember it’s not portable): You might also be interested in strtoumax and strtoimax which are standard functions in C99. For example you could say: Anyway, stay away from atoi: The call atoi(str) … Read more
Openssl : error “self signed certificate in certificate chain”
You have a certificate which is self-signed, so it’s non-trusted by default, that’s why OpenSSL complains. This warning is actually a good thing, because this scenario might also rise due to a man-in-the-middle attack. To solve this, you’ll need to install it as a trusted server. If it’s signed by a non-trusted CA, you’ll have … Read more
What does “dereferencing” a pointer mean?
Reviewing the basic terminology It’s usually good enough – unless you’re programming assembly – to envisage a pointer containing a numeric memory address, with 1 referring to the second byte in the process’s memory, 2 the third, 3 the fourth and so on…. What happened to 0 and the first byte? Well, we’ll get to … Read more
c stack smashing detected
I’ve created a file which prints Hello, world as many times at the user wants to give input. No matter what the number entered it always results in a “stack smash”. Here is the program, can anyone come up with a conclusion to why it is doing this? Here is the “traceback” that occurs after … Read more
1 = false and 0 = true?
It is common for comparison functions to return 0 on “equals”, so that they can also return a negative number for “less than” and a positive number for “greater than”. strcmp() and memcmp() work like this. It is, however, idiomatic for zero to be false and nonzero to be true, because this is how the … Read more
dereferencing pointer to incomplete type
I saw a question the other day where someone inadvertently used an incomplete type by specifying something like The compiler knew that struct A was a struct, despite A being totally undefined, by virtue of the struct keyword. That was in C++, where such usage of struct is atypical (and, it turns out, can lead … Read more