rm without -f: give a better diagnostic when euidaccess fails.

* src/remove.c (write_protected_non_symlink): Return int, not bool,
so that we can indicate failure too (as a postive error number).
(prompt): If write_protected_non_symlink fails, report that error
number and fail rather than charging ahead and removing the dubious
entry.  Redo the logic of printing a diagnostic so that we need to
invoke quote (full_filename (...)) only once.  More details at:
<http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/9952/focus=9996>

diff --git a/ChangeLog b/ChangeLog
index 6c31b28..13e1b74 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2007-03-08  Paul Eggert  <eggert@cs.ucla.edu>
+
+       rm without -f: give a better diagnostic when euidaccess fails.
+       * src/remove.c (write_protected_non_symlink): Return int, not bool,
+       so that we can indicate failure too (as a postive error number).
+       (prompt): If write_protected_non_symlink fails, report that error
+       number and fail rather than charging ahead and removing the dubious
+       entry.  Redo the logic of printing a diagnostic so that we need to
+       invoke quote (full_filename (...)) only once.  More details at:
+       <http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/9952/focus=9996>
+
 2007-03-08  Jim Meyering  <jim@meyering.net>
 
        Generalize a few more cvs-isms.

diff --git a/src/remove.c b/src/remove.c
index 97184eb..59ee9e5 100644 (file)
--- a/src/remove.c
+++ b/src/remove.c
@@ -704,20 +704,21 @@ is_empty_dir (int fd_cwd, char const *dir)
   return saved_errno == 0 ? true : false;
 }
 
-/* Return true if FILE is determined to be an unwritable non-symlink.
-   Otherwise, return false (including when lstat'ing it fails).
+/* Return -1 if FILE is an unwritable non-symlink,
+   0 if it is writable or some other type of file,
+   a positive error number if there is some problem in determining the answer.
    Set *BUF to the file status.
    This is to avoid calling euidaccess when FILE is a symlink.  */
-static bool
+static int
 write_protected_non_symlink (int fd_cwd,
                             char const *file,
                             Dirstack_state const *ds,
                             struct stat *buf)
 {
   if (cache_fstatat (fd_cwd, file, buf, AT_SYMLINK_NOFOLLOW) != 0)
-    return false;
+    return errno;
   if (S_ISLNK (buf->st_mode))
-    return false;
+    return 0;
   /* Here, we know FILE is not a symbolic link.  */
 
   /* In order to be reentrant -- i.e., to avoid changing the working
@@ -771,9 +772,16 @@ write_protected_non_symlink (int fd_cwd,
     size_t file_name_len
       = obstack_object_size (&ds->dir_stack) + strlen (file);
 
-    return (file_name_len < MIN (PATH_MAX, 8192)
-           ? euidaccess (full_filename (file), W_OK) != 0 && errno == EACCES
-           : euidaccess_stat (buf, W_OK) != 0);
+    if (MIN (PATH_MAX, 8192) <= file_name_len)
+      return - euidaccess_stat (buf, W_OK);
+    if (euidaccess (full_filename (file), W_OK) == 0)
+      return 0;
+    if (errno == EACCES)
+      return -1;
+
+    /* Perhaps some other process has removed the file, or perhaps this
+       is a buggy NFS client.  */
+    return errno;
   }
 }
 
@@ -794,75 +802,73 @@ prompt (int fd_cwd, Dirstack_state const *ds, char const *filename,
        struct rm_options const *x, enum Prompt_action mode,
        Ternary *is_empty)
 {
-  bool write_protected = false;
+  int write_protected = 0;
 
   *is_empty = T_UNKNOWN;
 
   if (x->interactive == RMI_NEVER)
     return RM_OK;
 
-  if (((!x->ignore_missing_files & ((x->interactive == RMI_ALWAYS)
-                                   | x->stdin_tty))
-       && (write_protected = write_protected_non_symlink (fd_cwd, filename,
-                                                         ds, sbuf)))
-      || x->interactive == RMI_ALWAYS)
+  if (!x->ignore_missing_files
+      & ((x->interactive == RMI_ALWAYS) | x->stdin_tty))
+    write_protected = write_protected_non_symlink (fd_cwd, filename, ds, sbuf);
+
+  if (write_protected || x->interactive == RMI_ALWAYS)
     {
-      if (cache_fstatat (fd_cwd, filename, sbuf, AT_SYMLINK_NOFOLLOW) != 0)
+      if (write_protected <= 0
+         && cache_fstatat (fd_cwd, filename, sbuf, AT_SYMLINK_NOFOLLOW) != 0)
        {
          /* This happens, e.g., with `rm '''.  */
-         error (0, errno, _("cannot remove %s"),
-                quote (full_filename (filename)));
-         return RM_ERROR;
+         write_protected = errno;
        }
 
-      if (S_ISDIR (sbuf->st_mode) && !x->recursive)
+      if (write_protected <= 0)
        {
-         error (0, EISDIR, _("cannot remove %s"),
-                quote (full_filename (filename)));
-         return RM_ERROR;
+         /* Using permissions doesn't make sense for symlinks.  */
+         if (S_ISLNK (sbuf->st_mode) && x->interactive != RMI_ALWAYS)
+           return RM_OK;
+
+         if (S_ISDIR (sbuf->st_mode) && !x->recursive)
+           write_protected = EISDIR;
        }
 
-      /* Using permissions doesn't make sense for symlinks.  */
-      if (S_ISLNK (sbuf->st_mode))
+      char const *quoted_name = quote (full_filename (filename));
+
+      if (0 < write_protected)
        {
-         if (x->interactive != RMI_ALWAYS)
-           return RM_OK;
-         write_protected = false;
+         error (0, write_protected, _("cannot remove %s"), quoted_name);
+         return RM_ERROR;
        }
 
       /* Issue the prompt.  */
-      {
-       char const *quoted_name = quote (full_filename (filename));
-
-       /* FIXME: use a variant of error (instead of fprintf) that doesn't
-          append a newline.  Then we won't have to declare program_name in
-          this file.  */
-       if (S_ISDIR (sbuf->st_mode)
-           && x->recursive
-           && mode == PA_DESCEND_INTO_DIR
-           && ((*is_empty = (is_empty_dir (fd_cwd, filename) ? T_YES : T_NO))
-               == T_NO))
+      /* FIXME: use a variant of error (instead of fprintf) that doesn't
+        append a newline.  Then we won't have to declare program_name in
+        this file.  */
+      if (S_ISDIR (sbuf->st_mode)
+         && x->recursive
+         && mode == PA_DESCEND_INTO_DIR
+         && ((*is_empty = (is_empty_dir (fd_cwd, filename) ? T_YES : T_NO))
+             == T_NO))
+       fprintf (stderr,
+                (write_protected
+                 ? _("%s: descend into write-protected directory %s? ")
+                 : _("%s: descend into directory %s? ")),
+                program_name, quoted_name);
+      else
+       {
+         /* TRANSLATORS: You may find it more convenient to translate
+            the equivalent of _("%s: remove %s (write-protected) %s? ").
+            It should avoid grammatical problems with the output
+            of file_type.  */
          fprintf (stderr,
                   (write_protected
-                   ? _("%s: descend into write-protected directory %s? ")
-                   : _("%s: descend into directory %s? ")),
-                  program_name, quoted_name);
-       else
-         {
-           /* TRANSLATORS: You may find it more convenient to translate
-              the equivalent of _("%s: remove %s (write-protected) %s? ").
-              It should avoid grammatical problems with the output
-              of file_type.  */
-           fprintf (stderr,
-                    (write_protected
-                     ? _("%s: remove write-protected %s %s? ")
-                     : _("%s: remove %s %s? ")),
-                    program_name, file_type (sbuf), quoted_name);
-         }
+                   ? _("%s: remove write-protected %s %s? ")
+                   : _("%s: remove %s %s? ")),
+                  program_name, file_type (sbuf), quoted_name);
+       }
 
-       if (!yesno ())
-         return RM_USER_DECLINED;
-      }
+      if (!yesno ())
+       return RM_USER_DECLINED;
     }
   return RM_OK;
 }