BSD 4 release

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

static  char *sccsid = "@(#)comsat.c    4.2 (Berkeley) 10/20/80";
#include <stdio.h>
#include <sys/mx.h>
#include <sgtty.h>
#include <utmp.h>
#include <sys/types.h>
#include <stat.h>
#include <wait.h>
#include <signal.h>

/*
* comsat
*/
#define dprintf if (0) printf
int     xd;

struct  ctp {
       short   ctrl;
       short   ctrlarg;
       struct  sgttyb ctrlv;
} ctp;

#define MAXUTMP 100             /* down from init */

struct  utmp utmp[100];
int     nutmp;
int     uf;
unsigned utmpmtime;                     /* last modification time for utmp */
int     onalrm();

#define NAMLEN (sizeof (uts[0].ut_name) + 1)

main(argc, argv)
char **argv;
{
       register cc;
       char buf[BUFSIZ];

       if (fork())
               exit();
       chdir("/usr/spool/mail");
       if((uf = open("/etc/utmp",0)) < 0)
               perror("/etc/utmp"), exit(1);
       while (fork())
               wait(0);
       sleep(10);
       onalrm();
       sigset(SIGALRM, onalrm);
       sigignore(SIGTTOU);
       unlink("/dev/mail");
       xd = mpx("/dev/mail", 0666);
       if (xd < 0) {
               close(2);
               open("/dev/console", 1);
               perror("/dev/mail");
               exit(1);
       }
       while((cc=read(xd, buf, BUFSIZ)) >= 0) {
               dprintf("0: got %d bytes\n", cc);
               unpack(buf, cc);
       }
       _exit(1);
}

#define skip(rp, c)     ((struct rh *)(((char *)rp)+c))

unpack(rp, cc)
       register struct rh *rp;
{
       register struct rh *end;
       int i;

       i = 0;
       end = skip(rp, cc);
       while (rp < end) {
               dprintf("%d: ", ++i);
               if (rp->count==0) {
                       dprintf("%d byte control message\n", rp->ccount);
                       control(rp->index, rp+1, rp->ccount);
               } else {
                       dprintf("%*.*s\n", rp->count, rp->count, rp+1);
                       sighold(SIGALRM);
                       mailfor(rp+1);
                       sigrelse(SIGALRM);
               }
               rp->count += rp->ccount;
               if (rp->count & 1)
                       rp->count++;
               rp = skip(rp, rp->count);
               rp++;
       }
}

control(x, cb, cc)
       register char *cb;
{
       register char *end;
       int cmd;
       short *sp;
       struct wh or;

       end = cb + cc;
       cmd = *cb++;
       sp = (short *)cb+1;
       switch (cmd) {

       case M_WATCH:
               dprintf("attach %x, uid %d\n", x, *sp);
               attach(x, xd);
               break;

       case M_CLOSE:
               sp = (short *)cb;
               dprintf("detach %x, uid %d\n", x, *sp);
               detach(x, xd);
               break;

       case M_IOCTL:
               dprintf("ioctl %x\n", x);
               or.index = x;
               or.count = 0;
               or.ccount = sizeof ctp;
               or.data = (char *) &ctp.ctrlarg;
               ctp.ctrlarg = M_IOANS;
               write(xd, &or, sizeof or);
               break;
               
       default:
               dprintf("unknown command %d\n", cmd);
               return;
       }
}

onalrm()
{
       struct stat statbf;
       struct utmp *utp;

       dprintf("alarm\n");
       alarm(15);
       fstat(uf,&statbf);
       if (statbf.st_mtime > utmpmtime) {
               dprintf(" changed\n");
               utmpmtime = statbf.st_mtime;
               lseek(uf, 0, 0);
               nutmp = read(uf,utmp,sizeof(utmp))/sizeof(struct utmp);
       } else
               dprintf(" ok\n");
}

mailfor(name)
       char *name;
{
       register struct utmp *utp = &utmp[nutmp];
       register char *cp;
       char *rindex();
       int offset;

       dprintf("mailfor %s\n", name);
       cp = name;
       while (*cp && *cp != '@')
               cp++;
       if (*cp == 0) {
               dprintf("bad format\n");
               return;
       }
       *cp = 0;
       offset = atoi(cp+1);
       while (--utp >= utmp)
               if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name)))
                       if (fork() == 0) {
                               signal(SIGALRM, SIG_DFL);
                               alarm(30);
                               notify(utp, offset), exit(0);
                       } else
                               while (wait3(0, WNOHANG, 0) > 0)
                                       continue;
}

char *cr;

notify(utp, offset)
       register struct utmp *utp;
{
       FILE *tp;
       struct sgttyb gttybuf;
       char tty[20];
       char name[sizeof (utmp[0].ut_name) + 1];
       struct stat stb;

       strcpy(tty, "/dev/");
       strncat(tty, utp->ut_line, sizeof(utp->ut_line));
       dprintf("notify %s on %s\n", utp->ut_name, tty);
       if (stat(tty, &stb) == 0 && (stb.st_mode & 0100) == 0) {
               dprintf("wrong mode\n");
               return;
       }
       if ((tp = fopen(tty,"w")) == 0) {
               dprintf("fopen failed\n");
               return;
       }
       gtty(fileno(tp),&gttybuf);
       cr = (gttybuf.sg_flags & CRMOD) ? "" : "\r";
       strncpy(name, utp->ut_name, sizeof (utp->ut_name));
       name[sizeof (name) - 1] = 0;
       fprintf(tp,"%s\n\007New mail for %s\007 has arrived:%s\n",
           cr, name, cr);
       fprintf(tp,"----%s\n", cr);
       jkfprintf(tp, name, offset);
        fclose(tp);
}

jkfprintf(tp, name, offset)
       register FILE *tp;
{
       register FILE *fi;
       register int linecnt, charcnt;

       dprintf("HERE %s's mail starting at %d\n",
           name, offset);
       if ((fi = fopen(name,"r")) == NULL) {
               dprintf("Cant read the mail\n");
               return;
       }
       fseek(fi, offset, 0);
       linecnt = 7;
       charcnt = 560;
       /* 
        * print the first 7 lines or 560 characters of the new mail
        * (whichever comes first)
        */
       for (;;) {
               register ch;

               if ((ch = getc(fi)) == EOF) {  
                       fprintf(tp,"----%s\n", cr);
                       break;
               }
               if (ch == '\n') {  
                       fprintf(tp,"%s\n", cr);
                       if (linecnt-- < 0) {  
                               fprintf(tp,"...more...%s\n", cr);
                               break;
                       }
               } else if(linecnt <= 0) {  
                       fprintf(tp,"...more...%s\n", cr);
                       break;
               } else
                       putc(ch, tp);
               if (charcnt-- == 0) {   
                       fprintf(tp, "%s\n", cr);
                       break;
               }
       }
}