BSD 4 release

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

static char *sccsid = "@(#)who.c        4.2 (Berkeley) 11/1/80";
/*
* who
*/

#include <stdio.h>
#include <utmp.h>
#include <pwd.h>
#include <whoami.h>
#include <ctype.h>

#define NMAX sizeof(utmp.ut_name)
#define LMAX sizeof(utmp.ut_line)

struct utmp utmp;
struct passwd *pw;
struct passwd *getpwuid();

char *ttyname(), *rindex(), *ctime(), *strcpy();
main(argc, argv)
char **argv;
{
       register char *tp, *s;
       register FILE *fi;
       extern char _sobuf[];

       setbuf(stdout, _sobuf);
       s = "/etc/utmp";
       if(argc == 2)
               s = argv[1];
       if (argc==3) {
               tp = ttyname(0);
               if (tp)
                       tp = rindex(tp, '/') + 1;
               else {  /* no tty - use best guess from passwd file */
                       pw = getpwuid(getuid());
                       strcpy(utmp.ut_name, pw?pw->pw_name: "?");
                       strcpy(utmp.ut_line, "tty??");
                       time(&utmp.ut_time);
                       putline();
                       exit(0);
               }
       }
       if ((fi = fopen(s, "r")) == NULL) {
               puts("who: cannot open utmp");
               exit(1);
       }
       while (fread((char *)&utmp, sizeof(utmp), 1, fi) == 1) {
               if(argc==3) {
                       static char myname[]=sysname;
                       if (strcmp(utmp.ut_line, tp))
                               continue;
                       if (islower(*myname))
                               *myname = toupper(*myname);
                       printf("(%s) ",myname);
                       putline();
                       exit(0);
               }
               if(utmp.ut_name[0] == '\0' && argc==1)
                       continue;
               putline();
       }
}

putline()
{
       register char *cbuf;

       printf("%-*.*s %-*.*s", NMAX, NMAX, utmp.ut_name, LMAX, LMAX, utmp.ut_line);
       cbuf = ctime(&utmp.ut_time);
       printf("%.12s\n", cbuf+4);
}