Reading long int using scanf

Question

To read an int using scanf we use:

scanf(\"%d\", &i);

What if i is a long not int??

Answer 1

Each conversion specifier expects its corresponding argument to be of a specific type; if the argument's type does not match the expected type, then the behavior is undefined. If you want to read into a long with scanf(), you need to use the %ld conversion specifier:

long i;
scanf("%ld", &i);

Check the online draft C standard (.pdf file), section 7.19.6.2, paragraph 11 for a complete listing of size modifiers and expected types.

Answer 2

scanf("%ld", &i);

You can also use "%Ld" for a long long (and depending on your compiler, sometimes also "%lld").

Take a look at the Conversions section of the scanf man page for more. (Just Google it if your system doesn't have manpages).

Answer 3

Just use

long l;

scanf("%ld", &l);

it gives me an irritating warning..

That warning is quite right. This is begging for stack corruption.

Answer 4

For gods sake:

long n;
scanf( "%ld", & n );

Answer 5

Check this, here is the answer: "%I64d"