Passing argument 4 of fwrite from incompatible pointer type

Question

I want to copy the content of the source file to the target file, but I get this warning:

warning: passing argument 4 of ‘fwrite’ from incompatible pointer type [-Wincompatible-pointer-types]

fwrite(target, sizeof(char), targetSize, sourceContent);

If i ignore the warning i get a segmentation fault.

FILE *source = fopen(argv[1], "r");
FILE *target = fopen(argv[2], "w");

if (source == NULL || target == NULL) {
    printf("One or both files do NOT exist\n");
    abort();
}

fseek(source, 0, SEEK_END);
long sourceSize = ftell(source);

fseek(source, 0, SEEK_SET);
char *sourceContent = (char *)malloc(sourceSize);
fread(sourceContent, sizeof(char), sourceSize, source);


long targetSize = sourceSize;
fwrite(target, sizeof(char), targetSize, sourceContent);

Answer 1

Both fread() and fwrite() take the buffer where to read/write as first argument, and the file as fourth.

// This is fine.
fread(sourceContent, sizeof(char), sourceSize, source);
// Swap the first and fourth argument in the fwrite call.
fwrite(sourceContent, sizeof(char), targetSize, target);