How to add buffering while using getc and putc - c

Question

I want to make copy/paste with using c FILE but i need to add read/write buffer too and I am not sure how to add it. Is there any function similar to regular read/write..Code is below.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char* argv[]) {
FILE* fsource, * fdestination;
printf("enter the name of source file:\n");
char sourceName[20], destinationName[20];
strcpy(sourceName, argv[1]);
strcpy(destinationName, argv[2]);
fsource = fopen(sourceName, "r");
if (fsource == NULL)
printf("read file did not open\n");
else
printf("read file opened sucessfully!\n");
fdestination = fopen(destinationName, "w");
if (fdestination == NULL)
printf("write file did not open\n");
else
printf("write file opened sucessfully!\n");
char pen = fgets(fsource);
while (pen != EOF)
{
fputc(pen, fdestination);
pen = fgets(fsource);
}
fclose(fsource);
fclose(fdestination);
return 0;
}

Answer 1

Here's a reworking of your code (sans some error handling) that reads and writes in 256-byte increments:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char *argv[]) {
char *sourceName = argv[0];
char destName[256];
snprintf(destName, 256, "%s.copy", sourceName);
printf("Copying %s -> %s\n", sourceName, destName);
FILE *fsource = fopen(sourceName, "rb");
FILE *fdest = fopen(destName, "w");
char buffer[256];
for (;;) {
size_t bytesRead = fread(buffer, 1, 256, fsource);
if (bytesRead == 0) {
break;
}
if (fwrite(buffer, 1, bytesRead, fdest) != bytesRead) {
printf("Failed to write all bytes!");
break;
}
printf("Wrote %ld bytes, position now %ld\n", bytesRead, ftell(fdest));
}
fclose(fsource);
fclose(fdest);
return 0;
}
The output is e.g.
$ ./so64481514
Copying ./so64481514 -> ./so64481514.copy
Wrote 256 bytes, position now 256
Wrote 256 bytes, position now 512
Wrote 256 bytes, position now 768
Wrote 256 bytes, position now 1024
[...]
Wrote 168 bytes, position now 12968