usr/src/lib/libutil/logout.c

/*
 * Copyright (c) 1988 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)logout.c    5.4 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/file.h>
#include <sys/time.h>
#include <utmp.h>

typedef struct utmp UTMP;

logout(line)
        register char *line;
{
        register int fd;
        UTMP ut;
        int rval;
        off_t lseek();
        time_t time();

        if ((fd = open(_PATH_UTMP, O_RDWR)) < 0)
                return(0);
        rval = 0;
        while (read(fd, (char *)&ut, sizeof(UTMP)) == sizeof(UTMP)) {
                if (!ut.ut_name[0] || strncmp(ut.ut_line, line, UT_LINESIZE))
                        continue;
                bzero(ut.ut_name, UT_NAMESIZE);
                bzero(ut.ut_host, UT_HOSTSIZE);
                (void)time(&ut.ut_time);
                (void)lseek(fd, -(long)sizeof(UTMP), L_INCR);
                (void)write(fd, (char *)&ut, sizeof(UTMP));
                rval = 1;
        }
        (void)close(fd);
        return(rval);
}