Question

what is mean 0f %p in c language?

Answer 1

It's printf style format specifier. %p is for pointers
types, while %x is for integers types and means "display the integer's
hexadecimal value".

Here's an example:

> cat format.c
#include <stdio.h>

int main(void)
{
int i = 10;

printf("dec -> %d\n", i);
printf("hex -> %x\n", i);
printf("addr -> %p\n", &i);

return (0);
}

> gcc -Wall -o format format.c && ./format
dec -> 10
hex -> a
addr -> 0xbfcc4894