X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Freadutmp.c;h=ec6e2759d197333ef6dad9e5d4573b582a9f3496;hb=23eecb48e39afd0d267d64d40ba6bf97aa865e13;hp=29b24a550796005a8b058c2c06933a4d27bd04b2;hpb=a456afefb13486e442be0cc6205b70e527d8f60b;p=gnulib.git
diff --git a/lib/readutmp.c b/lib/readutmp.c
index 29b24a550..ec6e2759d 100644
--- a/lib/readutmp.c
+++ b/lib/readutmp.c
@@ -1,10 +1,11 @@
/* GNU's read utmp module.
- Copyright (C) 1992-2000 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1992-2001, 2003-2006, 2009-2013 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
@@ -12,27 +13,30 @@
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 . */
/* Written by jla; revised by djm */
#include
+#include "readutmp.h"
+
+#include
#include
#include
#include
-#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
-# include
-#else
-# include
-#endif /* STDC_HEADERS || HAVE_STRING_H */
+#include
+#include
+#include
+#include
+#include
-#include "readutmp.h"
+#include "xalloc.h"
-char *xmalloc ();
-char *realloc ();
+#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. */
@@ -44,46 +48,67 @@ extract_trimmed_name (const STRUCT_UTMP *ut)
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';
+ /* 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-
+/* 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 non-zero and don't modify the parameters. */
+ 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 (const char *filename, int *n_entries, STRUCT_UTMP **utmp_buf)
+read_utmp (char const *file, size_t *n_entries, STRUCT_UTMP **utmp_buf,
+ int options)
{
- int n_read;
- STRUCT_UTMP *u;
+ 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 (filename);
+ UTMP_NAME_FUNCTION (file);
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;
- }
+ 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 ();
@@ -96,36 +121,39 @@ read_utmp (const char *filename, int *n_entries, STRUCT_UTMP **utmp_buf)
#else
int
-read_utmp (const char *filename, int *n_entries, STRUCT_UTMP **utmp_buf)
+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;
- 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
+ size_t n_read = 0;
+ size_t n_alloc = 0;
+ STRUCT_UTMP *utmp = NULL;
+ int saved_errno;
+ FILE *f = fopen (file, "r");
+
+ if (! f)
+ return -1;
+
+ for (;;)
{
- fclose (utmp);
- return 1;
+ 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);
}
- /* 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;
+ saved_errno = ferror (f) ? errno : 0;
+ if (fclose (f) != 0)
+ saved_errno = errno;
+ if (saved_errno != 0)
+ {
+ free (utmp);
+ errno = saved_errno;
+ return -1;
+ }
- *n_entries = size / sizeof (STRUCT_UTMP);
- *utmp_buf = buf;
+ *n_entries = n_read;
+ *utmp_buf = utmp;
return 0;
}