how to read byte by byte from a file - c

Question

I want to read the 4 first bytes from a binnary file which is a song.wav type. In a .wav file the 4 first bytes must be 52-46-49-49 and I have to read them to check later if they are true.
The thing is that I have a compile arror at the fread line which says invalid conversion from "unsigned char" to "void" and initialzing argument 1 of 'size_t fread(void*,size_t,size_t,FILE*) and i dont know what it means.
I saw in a previous topic tha this is the way that fread must be done if i want to read byte by byte. If anyone has any idea of how i can read byte by byte and store them in an array that be great. Thank you.
void checksong(char *argv[]){
FILE *myfile;
int i;
unsigned char k[4];
myfile=fopen(argv[2],"r");
i=0;
for(i=0; i<4; i++){
fread(k[i],1,1,myfile);
}
for(i=0; i<4; i++){
printf("%c\n", k[i]);
}
return ;
}

Answer 1

It is a single error:
Invalid conversion from unsigned charto void* initializing argument 1 of
size_t fread(void*,size_t,size_t,FILE*)
It means k[i] is an unsigned char, and not a pointer. You should use &k[i] or k+i.
However, you don't really need to read byte by byte. You can read 4 bytes, no loops involved:
fread(k, 4, 1, myfile);
Printing the numbers:
for (i=0; i<4; i++)
printf("%d\n", k[i]);

Answer 2

In order to read exactly one byte and store it into k at index i, you need to provide the address of element i
for(i=0; i<4; i++){
fread(&k[i],1,1,myfile);
}
However, you'd rather read the whole 4 bytes in one go if you're interested in them 4. So no for loop at all, and just do:
fread(k,1,4,myfile);
It is also good practice to test the return code of fread (and any I/O operation for that matter) in case it fails. man fread for more information.

Answer 3

You can use just
char buffer[4];
fread(buffer,1,4,myfile);

Answer 4

you need not to use fread() Even the fgetc() works well. Simple coding. SImple as reading a text file.
#include <stdio.h>
int main(int argc, char** argv)
{
FILE* f = fopen("lak", "rb");
fseek(f,0,SEEK_END);
long lsize=0,i=0;
lsize = ftell(f);
rewind(f);
while(i<lsize){
int first = fgetc(f);
i++;
printf("first byte = %x\n", (unsigned)first); //you can do anything with
//first now
}
fclose(f);
return 0;
}