What is this program telling the operating system to do? When are system calls being made? Will any of these system calls result in the execution of privileged instructions? If so, describe the way the machine will transition between user mode and kernel mode as this program runs.

Subject: Operating Systems

#include int main() { FILE *infile; FILE *outfile; char buffer[255]; infile = fopen("input.dat", "r"); outfile = fopen("output.dat", "w+"); while(fgets(buffer, 255, (FILE*)infile)) { fputs(buffer, outfile); } fclose(outfile); fclose(infile); return 0; }