How to use int16_t or int32_t with functions like scanf [duplicate]

Question

The way that I understand int16_t or int32_t in C is that they are typedefed to be 16 and 32 bit numbers respectively on your computer. I believe you would use these when you need to guarentee a number is 16 or 32 bits because different systems do not always represent an int as 32 bits or a short as 16 bits (Is this assumption correct? I find mixed answers when I look online.).

My question is how would I use a function like scanf to get input from a user with a int16_t or a int32_t or any of the other typedefed number types when I require them to actually be 16 bits or 32 bits or whatever? Is there some sort of special string modifier? Normally if I wanted to get an int from a user without caring about how large it is actually represented as I would write something like this

scanf("%d", &int); 

This works if I pass in a int32_t but I assume it is only because an int on my system is 32 bits and it does not specifically give me a 32 bit number instead it just gives me an int. How would I go about getting number that is guarenteed to be 32 bits? I have looked on this page of string modifiers and a few other places but have found no mention of these typedefed number types.

Edit: Since receiving an answer to my question I have done some Googling and found this. I included it below for reference as well.

uppercase hexadecimal printf format for uintptr_t  #define SCNd16   "d" decimal scanf format for int16_t  #define SCNd32   "ld" decimal scanf format for int32_t  #define SCNd8   "hhd" decimal scanf format for int8_t  #define SCNdFAST16   "d" decimal scanf format for int_fast16_t  #define SCNdFAST32   "ld" decimal scanf format for int_fast32_t  #define SCNdFAST8   "hhd" decimal scanf format for int_fast8_t  #define SCNdLEAST16   "d" decimal scanf format for int_least16_t  #define SCNdLEAST32   "ld" decimal scanf format for int_least32_t  #define SCNdLEAST8   "hhd" decimal scanf format for int_least8_t  #define SCNdPTR   SCNd16 decimal scanf format for intptr_t  #define SCNi16   "i" generic-integer scanf format for int16_t  #define SCNi32   "li" generic-integer scanf format for int32_t  #define SCNi8   "hhi" generic-integer scanf format for int8_t  #define SCNiFAST16   "i" generic-integer scanf format for int_fast16_t  #define SCNiFAST32   "li" generic-integer scanf format for int_fast32_t  #define SCNiFAST8   "hhi" generic-integer scanf format for int_fast8_t  #define SCNiLEAST16   "i" generic-integer scanf format for int_least16_t  #define SCNiLEAST32   "li" generic-integer scanf format for int_least32_t  #define SCNiLEAST8   "hhi" generic-integer scanf format for int_least8_t  #define SCNiPTR   SCNi16 generic-integer scanf format for intptr_t  #define SCNo16   "o" octal scanf format for uint16_t  #define SCNo32   "lo" octal scanf format for uint32_t  #define SCNo8   "hho" octal scanf format for uint8_t  #define SCNoFAST16   "o" octal scanf format for uint_fast16_t  #define SCNoFAST32   "lo" octal scanf format for uint_fast32_t  #define SCNoFAST8   "hho" octal scanf format for uint_fast8_t  #define SCNoLEAST16   "o" octal scanf format for uint_least16_t  #define SCNoLEAST32   "lo" octal scanf format for uint_least32_t  #define SCNoLEAST8   "hho" octal scanf format for uint_least8_t  #define SCNoPTR   SCNo16 octal scanf format for uintptr_t  #define SCNu16   "u" decimal scanf format for uint16_t  #define SCNu32   "lu" decimal scanf format for uint32_t  #define SCNu8   "hhu" decimal scanf format for uint8_t  #define SCNuFAST16   "u" decimal scanf format for uint_fast16_t  #define SCNuFAST32   "lu" decimal scanf format for uint_fast32_t  #define SCNuFAST8   "hhu" decimal scanf format for uint_fast8_t  #define SCNuLEAST16   "u" decimal scanf format for uint_least16_t  #define SCNuLEAST32   "lu" decimal scanf format for uint_least32_t  #define SCNuLEAST8   "hhu" decimal scanf format for uint_least8_t  #define SCNuPTR   SCNu16 decimal scanf format for uintptr_t  #define SCNx16   "x" hexadecimal scanf format for uint16_t  #define SCNx32   "lx" hexadecimal scanf format for uint32_t  #define SCNx8   "hhx" hexadecimal scanf format for uint8_t  #define SCNxFAST16   "x" hexadecimal scanf format for uint_fast16_t  #define SCNxFAST32   "lx" hexadecimal scanf format for uint_fast32_t  #define SCNxFAST8   "hhx" hexadecimal scanf format for uint_fast8_t  #define SCNxLEAST16   "x" hexadecimal scanf format for uint_least16_t  #define SCNxLEAST32   "lx" hexadecimal scanf format for uint_least32_t  #define SCNxLEAST8   "hhx" hexadecimal scanf format for uint_least8_t  #define SCNxPTR   SCNx16 hexadecimal scanf format for uintptr_t 

Answer 1

For those you need to use the macros from inttypes.h such as SCNd64 or SCNu32 etc.

scanf("%" SCNd32, &x);