Question

I got some code and I want improve it to find and replace bytes in file
so
I want to find all origbytes in FILE and then replace it with newbytes
then save file, I know how to open, write and save, but hot I can find bytes in char?

 FILE* file;
 file = fopen("/Users/Awesome/Desktop/test", "r+b");
 int size = sizeof(file)+1;
 char bytes [size];
 fgets(bytes, size, file);
 for (int i=0; i<size; i++){ 
     char origbytes  []  = {0x00, 0x00};
     char newbytes   []  = {0x11, 0x11};
     if (strcmp(bytes[i], origbytes)) //Here the problem
     {
         fseek(file, i, SEEK_SET);
         fwrite(newbytes, sizeof(newbytes), 1, file);
     }
 }
 fclose(file);

Answer 1

strcmp() is for string compare and not character compare. Two characters can be compared directly

if ( bytes[i] == origbytes[something] )

Also you you should not apply sizeof() on a file pointer to determine file size. You should seek to the end of file using fseek and then query ftell except for binary files. For binary files, use something like fstat

One more thing to note is that fgets returns much before the EOF if it sees a newline. Hence in your code, you may not read entire file contents even after doing the changes that we suggested. You need to use fread appropriately