1 static char *sccsid = "@(#)update.c 4.2 (Berkeley) 10/16/80"; 2 /* 3 * Update the file system every 30 seconds. 4 * For cache benefit, open certain system directories. 5 */ 6 7 #include <signal.h> 8 9 char *fillst[] = { 10 "/bin", 11 "/lib", 12 "/usr", 13 "/usr/bin", 14 "/usr/lib", 15 "/usr/ucb", 16 0, 17 }; 18 19 main() 20 { 21 char **f; 22 23 if(fork()) 24 exit(0); 25 close(0); 26 close(1); 27 close(2); 28 for(f = fillst; *f; f++) 29 open(*f, 0); 30 dosync(); 31 for(;;) 32 pause(); 33 } 34 35 dosync() 36 { 37 sync(); 38 signal(SIGALRM, dosync); 39 alarm(30); 40 } 41