/* GNU's read utmp module.
- Copyright (C) 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1992-2001, 2003-2006, 2009-2014 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.
+ the Free Software Foundation; either version 3 of the License, 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
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. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by jla; revised by djm */
#include <config.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 "error.h"
-char *xmalloc ();
+#include <errno.h>
+#include <stdio.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "xalloc.h"
-STRUCT_UTMP *utmp_contents = 0;
+#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 (ut)
- const STRUCT_UTMP *ut;
+extract_trimmed_name (const STRUCT_UTMP *ut)
{
char *p, *trimmed_name;
- trimmed_name = xmalloc (sizeof (ut->ut_name) + 1);
- strncpy (trimmed_name, ut->ut_name, sizeof (ut->ut_name));
- /* 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->ut_name)] = ' ';
- p = strchr (trimmed_name, ' ');
- if (p != NULL)
- *p = '\0';
+ 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 file FILENAME into UTMP_CONTENTS and return the
- number of entries it contains. */
+/* Is the utmp entry U desired by the user who asked for OPTIONS? */
+
+static bool
+desirable_utmp_entry (STRUCT_UTMP const *u, int options)
+{
+ bool user_proc = IS_USER_PROCESS (u);
+ if ((options & READ_UTMP_USER_PROCESS) && !user_proc)
+ return false;
+ if ((options & READ_UTMP_CHECK_PIDS)
+ && user_proc
+ && 0 < UT_PID (u)
+ && (kill (UT_PID (u), 0) < 0 && errno == ESRCH))
+ return false;
+ return true;
+}
+
+/* Read the utmp entries corresponding to file FILE 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.
+ If OPTIONS & READ_UTMP_CHECK_PIDS is nonzero, omit entries whose
+ process-IDs do not currently exist. */
+
+#ifdef UTMP_NAME_FUNCTION
+
+int
+read_utmp (char const *file, size_t *n_entries, STRUCT_UTMP **utmp_buf,
+ int options)
+{
+ size_t n_read = 0;
+ size_t n_alloc = 0;
+ STRUCT_UTMP *utmp = NULL;
+ 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 (file);
+
+ SET_UTMP_ENT ();
+
+ while ((u = GET_UTMP_ENT ()) != NULL)
+ if (desirable_utmp_entry (u, options))
+ {
+ if (n_read == n_alloc)
+ utmp = x2nrealloc (utmp, &n_alloc, sizeof *utmp);
+
+ utmp[n_read++] = *u;
+ }
+
+ END_UTMP_ENT ();
+
+ *n_entries = n_read;
+ *utmp_buf = utmp;
+
+ return 0;
+}
+
+#else
int
-read_utmp (filename)
- const char *filename;
+read_utmp (char const *file, size_t *n_entries, STRUCT_UTMP **utmp_buf,
+ int options)
{
- FILE *utmp;
- struct stat file_stats;
- size_t n_read;
- size_t size;
+ size_t n_read = 0;
+ size_t n_alloc = 0;
+ STRUCT_UTMP *utmp = NULL;
+ int saved_errno;
+ FILE *f = fopen (file, "r");
- if (utmp_contents)
+ if (! f)
+ return -1;
+
+ for (;;)
{
- free (utmp_contents);
- utmp_contents = 0;
+ if (n_read == n_alloc)
+ utmp = x2nrealloc (utmp, &n_alloc, sizeof *utmp);
+ if (fread (&utmp[n_read], sizeof utmp[n_read], 1, f) == 0)
+ break;
+ n_read += desirable_utmp_entry (&utmp[n_read], options);
}
- utmp = fopen (filename, "r");
- if (utmp == NULL)
- error (1, errno, "%s", filename);
-
- fstat (fileno (utmp), &file_stats);
- size = file_stats.st_size;
- if (size > 0)
- utmp_contents = (STRUCT_UTMP *) xmalloc (size);
- else
+ saved_errno = ferror (f) ? errno : 0;
+ if (fclose (f) != 0)
+ saved_errno = errno;
+ if (saved_errno != 0)
{
- fclose (utmp);
- return 0;
+ free (utmp);
+ errno = saved_errno;
+ return -1;
}
- /* Use < instead of != in case the utmp just grew. */
- n_read = fread (utmp_contents, 1, size, utmp);
- if (ferror (utmp) || fclose (utmp) == EOF
- || n_read < size)
- error (1, errno, "%s", filename);
+ *n_entries = n_read;
+ *utmp_buf = utmp;
- return size / sizeof (STRUCT_UTMP);
+ return 0;
}
+
+#endif
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