BSD 3 development

[unix-history] / .ref-BSD-2 / upgrade / src / last.c

/*
* NAME: last
*
* SYNOPSIS: last [-] [name ...]
*
* DESCRIPTION: Displays login history of named users or tty's.
*               Last with no argument prints history for all users.
*               Last - displays history for all non-class users.
*
* EXTERNAL ROUTINES USED: bread.c blseek.c
*
* AUTHOR - Howard P. Katseff
*/

struct {char c1, c2, c3, c4;};
struct {long l1;};
int     allflag;
char buf[32];
extern  fout;

main(argc, argv)
char **argv; {
       register char tty;
       register char **p;
       register char *q;
       int f, i, count;
       int intrp(), qintrp();
       long lx;
       long otime, ntime;
       long logouts[128];

       count = 0;
       fout = dup(1);
       if (allflag = argc==1) argv--;
       f = open("/usr/adm/wtmp", 0);
       if (f < 0) {
               printf("Can't open /usr/adm/wtmp\n");
               exit();
               }
x:      fstat(f, buf);

       for (i=0; i<127; i++) logouts[i] = 0;

       lx.c2 = 0;
       lx.c1 = buf[9];
       lx.c3 = buf[10] & 0360;
       lx.c4 = buf[11];

       blseek(f, lx, 0);
       lx =- 16;

       if ((signal(2,1) && 01) == 0) {
               signal(2, &intrp);
               signal(3, &qintrp);
               }

       for(;;) {
               if (lx < 16) {
                       f = open("/usr/adm/owtmp", 0);
                       if (count++ == 0 && f > 0) goto x;
                       q = ctime(buf+10);
                       printf("\nwtmp begins at  %10.10s  %5.5s \n",
                               q, 11+q);
                       flush();
                       exit();
                       }

               if (bread(f, buf+16, -16) < 16) {
                       perror("impossible error");
                       exit();
                       }

               for (p = 1+argv; *p != -1; p++) {
                       if (equal(*p, buf)) {
                               tty = buf[8];
                               q = ctime(buf+10);
                               if (tty >= ' ') 
                                       printf("%8.8s  tty%c  %10.10s  %5.5s ",
                                               buf, tty, q, 11+q);
                               else
                                       printf("%8.8s  tty^%c %10.10s  %5.5s ",
                                               buf, tty+0140, q, 11+q);
                               otime = (buf+10)->l1;
                               ntime = logouts[tty];
                               if (ntime == 0) {
                                       printf("  still logged in\n");
                                       }
                               else {
                                       if (ntime <= 0) {
                                               ntime = -ntime;
                                               printf("- crash");
                                               }
                                       else printf("- %5.5s", 11+ctime(&ntime));
                                       otime = ntime - otime;
                                       otime =+ 231231630;
                                       if (otime < 231318030)
                                               printf("  (%5.5s)\n", 11+
                                               ctime(&otime));
                                       else
                                               printf(" (%ld+%5.5s)\n",
                                               (otime-231231630)/86400,
                                               11+ctime(&otime));
                                       }
                               flush();
                               break;
                               }
                       }
               lx =- 16;

               if (buf[0] == '\0') {
                       tty = buf[8];
                       if (tty == '~')
                           for (i=0; i<127; i++) logouts[i] = -(buf+10)->l1;
                       else logouts[tty] = (buf+10)->l1;
                       }
               }
       }


equal(c1, c2)
char *c1, *c2; {
       int i;

       if (allflag && (*c2 != '\0' || *(c2+8) >= '|')) return(1);

       if (*(c1+1) == '\0') {
               if ((*c1 == '-') || (*c1 == 'x')) {
                       if (*c2 == '\0' && *(c2+8) < '|') return(0);
                       if (*c2 >= '0' && *c2 <= '9') return(0);
                       if (*(c2+2) >= '0' && *(c2+2) <= '9') return(0);
                       for(i=0; i<8; i++) if (*c2++ == '-') return(0);
                       return(1);
                       }

               if (*c1 == *(c2+8)  &&  (*c1 >= '|' || *c2 != '\0')) return(1);

               return(0);
               }

       for (i=0; i<8; i++) {
               if (*c1 == '\0') return(*c2 == ' ');
               if (*c1++ != *c2++) return(0);
               }

       return(1);
       }


intrp() {
       register char *q;

       signal(2,1);
       fout = 1;
       *(&fout+1) = 1;
       *(&fout+2) = 0;
       *(&fout+3) = 0;

       q = ctime(buf+10);
       printf("\ninterrupted at  %10.10s  %5.5s \n",
               q, 11+q);

       exit();
       }
qintrp() {
       register char *q;

       signal(3, &qintrp);
       fout = 1;
       *(&fout+1) = 1;
       *(&fout+2) = 0;
       *(&fout+3) = 0;

       q = ctime(buf+10);
       printf("\ninterrupted at  %10.10s  %5.5s \n",
               q, 11+q);

       }

/*
* NAMES:  bread(), brseek(), blseek()
*
* DESCRIPTION:
*       This is a buffered read package which simulates  read(), seek() and
*      lseek().
*       Bread may be called with a negative nbytes which causes it to
*      read backwards.  In this case, buffer should point to the first
*      byte following the buffer.  If only a partial read is possible
*      (due to beginning of file), only the last bytes of the buffer
*      will be filled.
*/

int     i, j, k;
int     nl, nr;
char    *next;
char    b[512];

bread(file, buff, nbytes)
char *buff; {
       register nb;

       if (nbytes > 0) {
               for (nb=nbytes; nb>0; nb--) {
                       if (nr == 0) {
                               nr = read(file, next=b, 512);
                               nl = 0;
                               if (nr < 0) return(-1);
                               if (nr == 0) return(nbytes-nb);
                               }
                       *buff++ = *next++;
                       nr--;
                       nl++;
                       }
               }
       else {
               nbytes = -nbytes;
               for (nb=nbytes; nb>0; nb--) {
                       if (nl == 0) {
                               seek(file, -(512 + nr), 1);
                               nl = read(file, b, 512);
                               if (nl < 0) {
                                       for (k=511; k>0; k--) {
                                               seek(file, 1, 1);
                                               nl = read(file, b, k);
                                               if (nl >= 0) break;
                                               }
                                       if (nl < 0) return(nbytes-nb);
                                       }
                               if (nl == 0) return(nbytes-nb);
                               next = b + nl;
                               nr = 0;
                               }
                       *--buff = *--next;
                       nr++;
                       nl--;
                       }
               }
       return(nbytes);
       }


brseek(file, offset, flag) {
       nl = 0;
       nr = 0;
       return(seek(file,offset,flag));
       }


blseek(file, offset, flag) 
long offset; {
       nl = 0;
       nr = 0;
       return(lseek(file,offset,flag));
       }