glibc/login/getutline_r.c

80 lines
2.3 KiB
C

/* Copyright (C) 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <utmp.h>
/* For implementing this function we don't use the getutent_r function
because we can avoid the reposition on every new entry this way. */
int
getutline_r (const struct utmp *line, struct utmp **utmp,
struct utmp_data *utmp_data)
{
/* Open utmp file if not already done. */
if (utmp_data->ut_fd == -1)
{
setutent_r (utmp_data);
if (utmp_data->ut_fd == -1)
return -1;
}
/* Position file correctly. */
if (lseek (utmp_data->ut_fd, utmp_data->loc_utmp, SEEK_SET) == -1)
return -1;
while (1)
{
/* Read the next entry. */
if (read (utmp_data->ut_fd, &utmp_data->ubuf, sizeof (struct utmp))
!= sizeof (struct utmp))
{
utmp_data->loc_utmp = 0; /* Mark UTMP_DATA->ubuf invalid. */
errno = ESRCH;
return -1;
}
/* Update position pointer. */
utmp_data->loc_utmp += sizeof (struct utmp);
#if _HAVE_UT_TYPE - 0
if (utmp_data->ubuf.ut_type == USER_PROCESS
&& strncmp (line->ut_line, utmp_data->ubuf.ut_line,
sizeof line->ut_line) == 0)
/* Stop if we found an user entry. */
break;
if (utmp_data->ubuf.ut_type == LOGIN_PROCESS)
/* Stop if we found a login entry. */
break;
#else /* !_HAVE_UT_TYPE */
if (strncmp (line->ut_line, utmp_data->ubuf.ut_line,
sizeof line->ut_line) == 0)
/* Stop if the line match. */
break;
#endif
}
*utmp = &utmp_data->ubuf;
return 0;
}