#include /** ** User function W: exit, sleep, write, getpid, gettime ** ** Reports its presence, then iterates 'n' times printing identifying ** information and sleeping, before exiting. ** ** Invoked as: userW x [ n [ s ] ] ** where x is the ID character ** n is the iteration count (defaults to 20) ** s is the sleep time (defaults to 3 seconds) */ USERMAIN(main) { int count = 20; // default iteration count char ch = 'w'; // default character to print int nap = 3; // nap length char buf[128]; // process the command-line arguments switch (argc) { case 4: nap = str2int(argv[3], 10); // FALL THROUGH case 3: count = str2int(argv[2], 10); // FALL THROUGH case 2: ch = argv[1][0]; break; default: sprint(buf, "userW: argc %d, args: ", argc); cwrites(buf); for (int i = 0; i <= argc; ++i) { sprint(buf, " %s", argv[argc] ? argv[argc] : "(null)"); cwrites(buf); } cwrites("\n"); } // announce our presence int pid = getpid(); uint32_t now = gettime(); sprint(buf, " %c[%d,%u]", ch, pid, now); swrites(buf); write(CHAN_SIO, &ch, 1); for (int i = 0; i < count; ++i) { now = gettime(); sprint(buf, " %c[%d,%u] ", ch, pid, now); swrites(buf); sleep(SEC_TO_MS(nap)); } exit(0); return (42); // shut the compiler up! }