mirror of
https://git.savannah.gnu.org/git/coreutils.git
synced 2025-09-10 07:59:52 +02:00
150 lines
3.6 KiB
C
150 lines
3.6 KiB
C
/* GNU's read utmp module.
|
|
Copyright (C) 1992-2001, 2003, 2004 Free Software Foundation, Inc.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software Foundation,
|
|
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
|
|
|
|
/* Written by jla; revised by djm */
|
|
|
|
#include <config.h>
|
|
|
|
#include "readutmp.h"
|
|
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
|
|
#include "xalloc.h"
|
|
|
|
#if USE_UNLOCKED_IO
|
|
# include "unlocked-io.h"
|
|
#endif
|
|
|
|
/* Copy UT->ut_name into storage obtained from malloc. Then remove any
|
|
trailing spaces from the copy, NUL terminate it, and return the copy. */
|
|
|
|
char *
|
|
extract_trimmed_name (const STRUCT_UTMP *ut)
|
|
{
|
|
char *p, *trimmed_name;
|
|
|
|
trimmed_name = xmalloc (sizeof (UT_USER (ut)) + 1);
|
|
strncpy (trimmed_name, UT_USER (ut), sizeof (UT_USER (ut)));
|
|
/* Append a trailing NUL. Some systems pad names shorter than the
|
|
maximum with spaces, others pad with NULs. Remove any trailing
|
|
spaces. */
|
|
trimmed_name[sizeof (UT_USER (ut))] = '\0';
|
|
for (p = trimmed_name + strlen (trimmed_name);
|
|
trimmed_name < p && p[-1] == ' ';
|
|
*--p = '\0')
|
|
continue;
|
|
return trimmed_name;
|
|
}
|
|
|
|
/* Read the utmp entries corresponding to file FILENAME into freshly-
|
|
malloc'd storage, set *UTMP_BUF to that pointer, set *N_ENTRIES to
|
|
the number of entries, and return zero. If there is any error,
|
|
return -1, setting errno, and don't modify the parameters. */
|
|
|
|
#ifdef UTMP_NAME_FUNCTION
|
|
|
|
int
|
|
read_utmp (const char *filename, size_t *n_entries, STRUCT_UTMP **utmp_buf)
|
|
{
|
|
size_t n_read;
|
|
size_t n_alloc = 4;
|
|
STRUCT_UTMP *utmp = xmalloc (n_alloc * sizeof *utmp);
|
|
STRUCT_UTMP *u;
|
|
|
|
/* Ignore the return value for now.
|
|
Solaris' utmpname returns 1 upon success -- which is contrary
|
|
to what the GNU libc version does. In addition, older GNU libc
|
|
versions are actually void. */
|
|
UTMP_NAME_FUNCTION (filename);
|
|
|
|
SET_UTMP_ENT ();
|
|
|
|
n_read = 0;
|
|
while ((u = GET_UTMP_ENT ()) != NULL)
|
|
{
|
|
if (n_read == n_alloc)
|
|
{
|
|
utmp = xnrealloc (utmp, n_alloc, 2 * sizeof *utmp);
|
|
n_alloc *= 2;
|
|
}
|
|
++n_read;
|
|
utmp[n_read - 1] = *u;
|
|
}
|
|
|
|
END_UTMP_ENT ();
|
|
|
|
*n_entries = n_read;
|
|
*utmp_buf = utmp;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#else
|
|
|
|
int
|
|
read_utmp (const char *filename, size_t *n_entries, STRUCT_UTMP **utmp_buf)
|
|
{
|
|
FILE *utmp;
|
|
struct stat file_stats;
|
|
size_t n_read;
|
|
size_t size;
|
|
STRUCT_UTMP *buf;
|
|
|
|
utmp = fopen (filename, "r");
|
|
if (utmp == NULL)
|
|
return -1;
|
|
|
|
if (fstat (fileno (utmp), &file_stats) != 0)
|
|
{
|
|
int e = errno;
|
|
fclose (utmp);
|
|
errno = e;
|
|
return -1;
|
|
}
|
|
size = file_stats.st_size;
|
|
buf = xmalloc (size);
|
|
n_read = fread (buf, sizeof *buf, size / sizeof *buf, utmp);
|
|
if (ferror (utmp))
|
|
{
|
|
int e = errno;
|
|
free (buf);
|
|
fclose (utmp);
|
|
errno = e;
|
|
return -1;
|
|
}
|
|
if (fclose (utmp) != 0)
|
|
{
|
|
int e = errno;
|
|
free (buf);
|
|
errno = e;
|
|
return -1;
|
|
}
|
|
|
|
*n_entries = n_read;
|
|
*utmp_buf = buf;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif
|