| 1 | static char *sccsid = "@(#)wall.c 4.1 (Berkeley) 10/1/80"; |
| 2 | /* |
| 3 | * wall.c - Broadcast a message to all users. |
| 4 | * |
| 5 | * This program is not related to David Wall, whose Stanford Ph.D. thesis |
| 6 | * is entitled "Mechanisms for Broadcast and Selective Broadcast". |
| 7 | */ |
| 8 | |
| 9 | #include <stdio.h> |
| 10 | #include <utmp.h> |
| 11 | #include <time.h> |
| 12 | #define USERS 128 |
| 13 | |
| 14 | char mesg[3000]; |
| 15 | int msize,sline; |
| 16 | struct utmp utmp[USERS]; |
| 17 | char *strcpy(); |
| 18 | char *strcat(); |
| 19 | char who[9] = "???"; |
| 20 | long clock; |
| 21 | struct tm *localtime(); |
| 22 | struct tm *localclock; |
| 23 | |
| 24 | main(argc, argv) |
| 25 | char *argv[]; |
| 26 | { |
| 27 | register i; |
| 28 | register char c; |
| 29 | register struct utmp *p; |
| 30 | FILE *f; |
| 31 | |
| 32 | if((f = fopen("/etc/utmp", "r")) == NULL) { |
| 33 | fprintf(stderr, "Cannot open /etc/utmp\n"); |
| 34 | exit(1); |
| 35 | } |
| 36 | clock = time( 0 ); |
| 37 | localclock = localtime( &clock ); |
| 38 | fread((char *)utmp, sizeof(struct utmp), USERS, f); |
| 39 | fclose(f); |
| 40 | f = stdin; |
| 41 | if(argc >= 2) { |
| 42 | /* take message from unix file instead of standard input */ |
| 43 | if((f = fopen(argv[1], "r")) == NULL) { |
| 44 | fprintf(stderr,"Cannot open %s\n", argv[1]); |
| 45 | exit(1); |
| 46 | } |
| 47 | } |
| 48 | while((i = getc(f)) != EOF) mesg[msize++] = i; |
| 49 | fclose(f); |
| 50 | sline = ttyslot(2); /* 'utmp' slot no. of sender */ |
| 51 | if (sline) { |
| 52 | for (i=0;(c=utmp[sline].ut_name[i]) && i<sizeof(utmp[0].ut_name);i++) |
| 53 | who[i]=c; |
| 54 | who[i] = '\0'; /* sender initials */ |
| 55 | } |
| 56 | for(i=0; i<USERS; i++) { |
| 57 | p = &utmp[i]; |
| 58 | if(p->ut_name[0] == 0) |
| 59 | continue; |
| 60 | sleep(1); |
| 61 | sendmes(p->ut_line); |
| 62 | } |
| 63 | exit(0); |
| 64 | } |
| 65 | |
| 66 | sendmes(tty) |
| 67 | char *tty; |
| 68 | { |
| 69 | register i; |
| 70 | char t[50], buf[BUFSIZ]; |
| 71 | register char *cp; |
| 72 | register int c, ch; |
| 73 | FILE *f; |
| 74 | |
| 75 | i = fork(); |
| 76 | if(i == -1) { |
| 77 | fprintf(stderr, "Try again\n"); |
| 78 | return; |
| 79 | } |
| 80 | if(i) |
| 81 | return; |
| 82 | strcpy(t, "/dev/"); |
| 83 | strcat(t, tty); |
| 84 | |
| 85 | if((f = fopen(t, "w")) == NULL) { |
| 86 | fprintf(stderr,"cannot open %s\n", t); |
| 87 | exit(1); |
| 88 | } |
| 89 | setbuf(f, buf); |
| 90 | fprintf(f, "\n\a\a\aBroadcast Message from %s (%s) at %d:%02d ...\r\n\n" |
| 91 | ,who, utmp[sline].ut_line |
| 92 | , localclock -> tm_hour , localclock -> tm_min ); |
| 93 | /* fwrite(mesg, msize, 1, f); */ |
| 94 | for (cp = mesg, c = msize; c-- > 0; cp++) { |
| 95 | ch = *cp; |
| 96 | if (ch == '\n') |
| 97 | putc('\r', f); |
| 98 | putc(ch, f); |
| 99 | } |
| 100 | |
| 101 | /* |
| 102 | * Bitchin'. |
| 103 | */ |
| 104 | |
| 105 | exit(0); |
| 106 | } |