Research V7 development

[unix-history] / usr / src / cmd / wall.c

#include <stdio.h>
#include <utmp.h>
#define USERS   50

char    mesg[3000];
int     msize;
struct  utmp utmp[USERS];
char    *strcpy();
char    *strcat();

main(argc, argv)
char *argv[];
{
       register i;
       register struct utmp *p;
       FILE *f;

       if((f = fopen("/etc/utmp", "r")) == NULL) {
               fprintf(stderr, "Cannot open /etc/utmp\n");
               exit(1);
       }
       fread((char *)utmp, sizeof(struct utmp), USERS, f);
       fclose(f);
       f = stdin;
       if(argc >= 2) {
               if((f = fopen(argv[1], "r")) == NULL) {
                       fprintf(stderr,"Cannot open %s\n", argv[1]);
                       exit(1);
               }
       }
       while((i = getc(f)) != EOF) mesg[msize++] = i;
       fclose(f);
       for(i=0; i<USERS; i++) {
               p = &utmp[i];
               if(p->ut_name[0] == 0)
                       continue;
               sleep(1);
               sendmes(p->ut_line);
       }
       exit(0);
}

sendmes(tty)
char *tty;
{
       register i;
       char t[50], buf[BUFSIZ];
       FILE *f;

       i = fork();
       if(i == -1) {
               fprintf(stderr, "Try again\n");
               return;
       }
       if(i)
               return;
       strcpy(t, "/dev/");
       strcat(t, tty);

       if((f = fopen(t, "w")) == NULL) {
               fprintf(stderr,"cannot open %s\n", t);
               exit(1);
       }
       setbuf(f, buf);
       fprintf(f, "\a\a\aBroadcast Message ...\n\n");
       fwrite(mesg, msize, 1, f);
       exit(0);
}