#include <common.h> /** ** User function main #5: exit, fork, exec, write ** ** Iterates spawning copies of userW (and possibly userZ), reporting ** their PIDs as it goes. ** ** Invoked as: main5 x n b ** where x is the ID character ** n is the iteration count ** b is the w&z boolean */ USERMAIN(main) { int count = 5; // default iteration count char ch = '5'; // default character to print int alsoZ = 0; // also do userZ? char msgw[] = "*5w*"; char msgz[] = "*5z*"; char buf[128]; // process the command-line arguments switch (argc) { case 4: alsoZ = argv[3][0] == 't'; // FALL THROUGH case 3: count = str2int(argv[2], 10); // FALL THROUGH case 2: ch = argv[1][0]; break; default: sprint(buf, "main5: 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"); } // update the extra message strings msgw[1] = msgz[1] = ch; // announce our presence write(CHAN_SIO, &ch, 1); // set up the argument vector(s) // W: 15 iterations, 5-second sleep char *argsw[] = { "userW", "W", "15", "5", NULL }; // Z: 15 iterations char *argsz[] = { "userZ", "Z", "15", NULL }; for (int i = 0; i < count; ++i) { write(CHAN_SIO, &ch, 1); int whom = spawn(ProgW, argsw); if (whom < 1) { swrites(msgw); } if (alsoZ) { whom = spawn(ProgZ, argsz); if (whom < 1) { swrites(msgz); } } } exit(0); return (42); // shut the compiler up! }