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    5.2 (Berkeley) 2/17/89";
#endif /* LIBC_SCCS and not lint */

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

#define UTMPFILE        "/etc/utmp"

/* 0 on failure, 1 on success */

logout(line)
        register char *line;
{
        register FILE *fp;
        struct utmp ut;
        int rval;
        time_t time();

        if (!(fp = fopen(UTMPFILE, "r+")))
                return(0);
        rval = 0;
        while (fread((char *)&ut, sizeof(struct utmp), 1, fp) == 1) {
                if (!ut.ut_name[0] ||
                    strncmp(ut.ut_line, line, sizeof(ut.ut_line)))
                        continue;
                bzero(ut.ut_name, sizeof(ut.ut_name));
                bzero(ut.ut_host, sizeof(ut.ut_host));
                (void)time(&ut.ut_time);
                (void)fseek(fp, (long)-sizeof(struct utmp), L_INCR);
                (void)fwrite((char *)&ut, sizeof(struct utmp), 1, fp);
                (void)fseek(fp, (long)0, L_INCR);
                rval = 1;
        }
        (void)fclose(fp);
        return(rval);
}