date and time created 83/02/24 12:56:06 by mckusick

[unix-history] / usr / src / usr.bin / users / users.c

static char *sccsid = "@(#)users.c      4.1 (Berkeley) %G%";
/*
* users
*/
char    *malloc();

#include <stdio.h>
#include <utmp.h>

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

struct utmp utmp;

main(argc, argv)
char **argv;
{
       register char *tp, *s;
       register FILE *fi;

       s = "/etc/utmp";
       if(argc == 2)
               s = argv[1];
       if ((fi = fopen(s, "r")) == NULL) {
               puts("who: cannot open utmp");
               exit(1);
       }
       while (fread((char *)&utmp, sizeof(utmp), 1, fi) == 1) {
               if(utmp.ut_name[0] == '\0')
                       continue;
               putline();
       }
       summary();
}

char    *names[128];
char    **namp = names;
putline()
{
       char temp[NMAX+1];
       strncpy(temp, utmp.ut_name, NMAX);
       temp[NMAX] = 0;
       *namp = malloc(strlen(temp) + 1);
       strcpy(*namp++, temp);
}

scmp(p, q)
char **p, **q;
{
       return(strcmp(*p, *q));
}
summary()
{
       register char **p;

       qsort(names, namp - names, sizeof names[0], scmp);
       for (p=names; p < namp; p++) {
               if (p != names)
                       printf(" ");
               printf("%s", *p);
       }
       printf("\n");
}