system programing linux and unix !! explain this code !

8.5 fork and standard I/O Consider this code: #include main() Programming Exercises 281 FILE p int pid; char msg1[] = "Testing 1 2 3 .. "; char msg2 "Hello, helloln; if ( (fp= fopen ("testfile2 " , "w")) = NULL ) return 0 fprint f { fp, "%s ", msg1); if (pidfork))1 return 0 fprintf (fp, "s", msg2) fclose (fp) i return 1; Test this program. How many messages appear in the file? Explain the results. Compare this program to the output of forkdemol.c in the text 8.6 Background processing Compile and run this program: main() int i; if fork)0) Eor i-1i 10 i++ ) exit (0) printf ("still here. n" sleep(i) return 0 xplain what this program does and how it works. Unix shells allow users to run programs in the background. How is this program similar to a background process