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authorJim Meyering <jim@meyering.net>2006-02-02 21:25:06 +0000
committerJim Meyering <jim@meyering.net>2006-02-02 21:25:06 +0000
commitb88d20f97801465da4d0a24a6c3689b119b94eef (patch)
tree95dc6e3646876aa7c73f766ff05da3c2924b74d2
parent32c694b90895624f27b5dc1b67bec05c29f2e10b (diff)
downloadcoreutils-b88d20f97801465da4d0a24a6c3689b119b94eef.tar.xz
Eliminate the unwelcome (albeit unlikely) possibility of xmalloc
failure on deficient systems, and simplify gnulib lgpl dependencies. (rpl_lstat): Rewrite to use stat() in place of the xmalloc/lstat combination. Based on a patch from Bruno Haible.
-rw-r--r--lib/lstat.c45
1 files changed, 24 insertions, 21 deletions
diff --git a/lib/lstat.c b/lib/lstat.c
index f5a22b07b..9b9c33e41 100644
--- a/lib/lstat.c
+++ b/lib/lstat.c
@@ -1,6 +1,6 @@
/* Work around a bug of lstat on some systems
- Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free
+ Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free
Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
@@ -30,28 +30,28 @@
#include <sys/types.h>
#include <sys/stat.h>
-#include <stdlib.h>
#include <string.h>
+#include <errno.h>
#include "stat-macros.h"
-#include "xalloc.h"
/* lstat works differently on Linux and Solaris systems. POSIX (see
- `pathname resolution' in the glossary) requires that programs like `ls'
- take into consideration the fact that FILE has a trailing slash when
- FILE is a symbolic link. On Linux systems, the lstat function already
- has the desired semantics (in treating `lstat("symlink/",sbuf)' just like
- `lstat("symlink/.",sbuf)', but on Solaris it does not.
+ `pathname resolution' in the glossary) requires that programs like
+ `ls' take into consideration the fact that FILE has a trailing slash
+ when FILE is a symbolic link. On Linux and Solaris 10 systems, the
+ lstat function already has the desired semantics (in treating
+ `lstat ("symlink/", sbuf)' just like `lstat ("symlink/.", sbuf)',
+ but on Solaris 9 and earlier it does not.
If FILE has a trailing slash and specifies a symbolic link,
- then append a `.' to FILE and call lstat a second time. */
+ then use stat() to get more info on the referent of FILE.
+ If the referent is a non-directory, then set errno to ENOTDIR
+ and return -1. Otherwise, return stat's result. */
int
rpl_lstat (const char *file, struct stat *sbuf)
{
size_t len;
- char *new_file;
-
int lstat_result = lstat (file, sbuf);
if (lstat_result != 0 || !S_ISLNK (sbuf->st_mode))
@@ -59,19 +59,22 @@ rpl_lstat (const char *file, struct stat *sbuf)
len = strlen (file);
if (len == 0 || file[len - 1] != '/')
- return lstat_result;
+ return 0;
/* FILE refers to a symbolic link and the name ends with a slash.
- Append a `.' to FILE and repeat the lstat call. */
+ Call stat() to get info about the link's referent. */
- /* Add one for the `.' we'll append, and one more for the trailing NUL. */
- new_file = xmalloc (len + 1 + 1);
- memcpy (new_file, file, len);
- new_file[len] = '.';
- new_file[len + 1] = 0;
+ /* If stat fails, then we do the same. */
+ if (stat (file, sbuf) != 0)
+ return -1;
- lstat_result = lstat (new_file, sbuf);
- free (new_file);
+ /* If FILE references a directory, return 0. */
+ if (S_ISDIR (sbuf->st_mode))
+ return 0;
- return lstat_result;
+ /* Here, we know stat succeeded and FILE references a non-directory.
+ But it was specified via a name including a trailing slash.
+ Fail with errno set to ENOTDIR to indicate the contradiction. */
+ errno = ENOTDIR;
+ return -1;
}