/* GNU's read utmp module.   Copyright (C) 1992-2001 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 <stdio.h>#include <sys/types.h>#include <sys/stat.h>#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)# include <string.h>#else# include <strings.h>#endif /* STDC_HEADERS || HAVE_STRING_H */#include "readutmp.h"#include "unlocked-io.h"char *xmalloc ();char *realloc ();/* 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 space character.  Some systems pad names shorter than     the maximum with spaces, others pad with NULs.  Remove any spaces.  */  trimmed_name[sizeof (UT_USER (ut))] = ' ';  p = strchr (trimmed_name, ' ');  if (p != NULL)    *p = '\0';  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 non-zero and don't modify the parameters.  */#ifdef UTMP_NAME_FUNCTIONintread_utmp (const char *filename, int *n_entries, STRUCT_UTMP **utmp_buf){  int n_read;  STRUCT_UTMP *u;  STRUCT_UTMP *utmp = NULL;  /* 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)    {      ++n_read;      utmp = (STRUCT_UTMP *) realloc (utmp, n_read * sizeof (STRUCT_UTMP));      if (utmp == NULL)	return 1;      utmp[n_read - 1] = *u;    }  END_UTMP_ENT ();  *n_entries = n_read;  *utmp_buf = utmp;  return 0;}#elseintread_utmp (const char *filename, int *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;  fstat (fileno (utmp), &file_stats);  size = file_stats.st_size;  if (size > 0)    buf = (STRUCT_UTMP *) xmalloc (size);  else    {      fclose (utmp);      return 1;    }  /* Use < instead of != in case the utmp just grew.  */  n_read = fread (buf, 1, size, utmp);  if (ferror (utmp) || fclose (utmp) == EOF      || n_read < size)    return 1;  *n_entries = size / sizeof (STRUCT_UTMP);  *utmp_buf = buf;  return 0;}#endif