[c] How can I get an int from stdio in C?

I have significant trouble with this...

printf("> ");
int x = getchar();

printf("got the number: %d", scanf("%d", &x));

Output

> 1234
got the number: 1

The typical way is with scanf:

int input_value;

scanf("%d", &input_value);

In most cases, however, you want to check whether your attempt at reading input succeeded. scanf returns the number of items it successfully converted, so you typically want to compare the return value against the number of items you expected to read. In this case you're expecting to read one item, so:

if (scanf("%d", &input_value) == 1)
    // it succeeded
else
    // it failed

Of course, the same is true of all the scanf family (sscanf, fscanf and so on).

The solution is quite simple ... you're reading getchar() which gives you the first character in the input buffer, and scanf just parsed it (really don't know why) to an integer, if you just forget the getchar for a second, it will read the full buffer until a newline char.

printf("> ");
int x;
scanf("%d", &x);
printf("got the number: %d", x);

Outputs

> [prompt expecting input, lets write:] 1234 [Enter]
got the number: 1234