Re: Too powerful rmdir
zhoulai...@melix wrote:
> I suppose this is a designing issue or a bug:
Thanks for the report. But the behavior you describe is not a bug but
simply a misunderstanding.
> You can remove an empty directory as you like, even if you don't have the
> right to read, write nor execute:
The permissions of the parent directory control whether you can remove
a file from within it. The permissions of the file being removed are
not the controlling factor. (And a directory is just a special file
and follows the same rules.)
> f...@ubuntu:~/Unix_Tutorial_8/5$ mkdir test
> f...@ubuntu:~/Unix_Tutorial_8/5$ ls -l
> total 4
> drwxr-xr-x 2 fu fu 4096 2009-08-12 06:39 test
You made the directory in '.' and so therefore we know that '.' allows
you to modify (create or destroy) contents in it.
> f...@ubuntu:~/Unix_Tutorial_8/5$ chmod ugo-rwx test/
> f...@ubuntu:~/Unix_Tutorial_8/5$ ls -l
> total 4
> d- 2 fu fu 4096 2009-08-12 06:39 test
The permissions on that target file are not a controlling factor in
whether you can remove it from its parent directory. The permissions
on the parent directory control whether you can create or remove files
from the parent directory.
> f...@ubuntu:~/Unix_Tutorial_8/5$ rmdir test
> f...@ubuntu:~/Unix_Tutorial_8/5$ ls -l
> total 0
> f...@ubuntu:~/Unix_Tutorial_8/5$
All correct. And I am compelled to note that this is all as per
traditional unix filesystem behavior for 40 years.
If you want to prevent a file from being removed (or created) then you
must remove write permission from the directory containing it.
Try this:
$ mkdir test
$ chmod a-w .
$ rmdir test
rmdir: failed to remove `test': Permission denied
In any case, even if this wasn't so, it is the kernel that enforces
permissions *not* an individual userspace command. Otherwise all it
would take to circumvent the permissions would be to use perl.
perl -e 'rmdir("somedir");unlink("somefile");'
Bob
Re: [PATCH] ls: Use pretty UTF-8 arrow when showing where symlinks point to
On Tue, 11.08.09 22:27, Pádraig Brady (p...@draigbrady.com) wrote: > this is equivalent I think: > >static const char *arrow = " -> "; > #ifdef HAVE_NL_LANGINFO >if (fancy_chars && STREQ (nl_langinfo (CODESET), "UTF-8")) > arrow = " \xe2\x86\x92 "; > #endif >DIRED_FPUTS_LITERAL (arrow, stdout); You evaluate the whole expression on every iteration. The whole point of making this variable static is to make sure this isn't necessary. Lennart -- Lennart PoetteringRed Hat, Inc. lennart [at] poettering [dot] net http://0pointer.net/lennart/ GnuPG 0x1A015CC4
Too powerful rmdir
Hello, I suppose this is a designing issue or a bug: You can remove an empty directory as you like, even if you don't have the right to read, write nor execute: f...@ubuntu:~/Unix_Tutorial_8/5$ mkdir test f...@ubuntu:~/Unix_Tutorial_8/5$ ls -l total 4 drwxr-xr-x 2 fu fu 4096 2009-08-12 06:39 test f...@ubuntu:~/Unix_Tutorial_8/5$ chmod ugo-rwx test/ f...@ubuntu:~/Unix_Tutorial_8/5$ ls -l total 4 d- 2 fu fu 4096 2009-08-12 06:39 test f...@ubuntu:~/Unix_Tutorial_8/5$ rmdir test f...@ubuntu:~/Unix_Tutorial_8/5$ ls -l total 0 f...@ubuntu:~/Unix_Tutorial_8/5$ -- Zhoulai FU Ecole Polytechnique (X-2005) Telecom Paris (2010)
Re: [PATCH] ls: Use pretty UTF-8 arrow when showing where symlinks point to
Lennart Poettering wrote:
> [Second version of the patch, makes this feature optional with --fancy-chars]
--fancy-chars :)
I'm not sure how serious this patch is.
How about:
alias lsf='ls -l --color | sed "s/ -> / $(tput bold)\u25aa\u25b6$(tput sgr0) /"'
cheers,
Pádraig.
p.s. this chunk is far too verbose
> +#ifdef HAVE_NL_LANGINFO
> + static const char *arrow = NULL;
> +
> + if (!arrow)
> + {
> + arrow = " -> ";
> +
> + if (fancy_chars)
> + {
> + const char *cs;
> + cs = nl_langinfo(CODESET);
> +
> + if (cs && strcmp(cs, "UTF-8") == 0)
> + arrow = " \xe2\x86\x92 ";
> + }
> + }
> + DIRED_FPUTS_LITERAL (arrow, stdout);
> +#else
> DIRED_FPUTS_LITERAL (" -> ", stdout);
> +#endif
this is equivalent I think:
static const char *arrow = " -> ";
#ifdef HAVE_NL_LANGINFO
if (fancy_chars && STREQ (nl_langinfo (CODESET), "UTF-8"))
arrow = " \xe2\x86\x92 ";
#endif
DIRED_FPUTS_LITERAL (arrow, stdout);
[PATCH] ls: Use pretty UTF-8 arrow when showing where symlinks point to
[Second version of the patch, makes this feature optional with --fancy-chars]
Diego Pettenò complained that "ls -l" doesn't use the UTF-8 arrow
character to show where symlinks point to. This tiny patch fixes that.
With this applied the character is used when the CODESET is UTF-8
otherwise we fall back to the traditional "->" arrow.
This is only enabled if --fancy-chars is passed as argument.
Ah, "ls -l" is so much prettier now!
For verification:
http://pastie.org/573270
---
src/ls.c | 33 +
1 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/src/ls.c b/src/ls.c
index 07e9cf1..0d5be7c 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -496,6 +496,11 @@ static enum indicator_style const indicator_style_types[] =
};
ARGMATCH_VERIFY (indicator_style_args, indicator_style_types);
+/* Use fancy Unicode characters in output. At this point this simply
+ replaces the -> arrow for symlinks by a real Unicode arrow. */
+
+static bool fancy_chars;
+
/* True means use colors to mark types. Also define the different
colors as well as the stuff for the LS_COLORS environment variable.
The LS_COLORS variable is now in a termcap-like format. */
@@ -758,6 +763,7 @@ enum
AUTHOR_OPTION = CHAR_MAX + 1,
BLOCK_SIZE_OPTION,
COLOR_OPTION,
+ FANCY_CHARS_OPTION,
DEREFERENCE_COMMAND_LINE_SYMLINK_TO_DIR_OPTION,
FILE_TYPE_INDICATOR_OPTION,
FORMAT_OPTION,
@@ -813,6 +819,7 @@ static struct option const long_options[] =
{"time", required_argument, NULL, TIME_OPTION},
{"time-style", required_argument, NULL, TIME_STYLE_OPTION},
{"color", optional_argument, NULL, COLOR_OPTION},
+ {"fancy-chars", no_argument, NULL, FANCY_CHARS_OPTION},
{"block-size", required_argument, NULL, BLOCK_SIZE_OPTION},
{"context", no_argument, 0, 'Z'},
{"author", no_argument, NULL, AUTHOR_OPTION},
@@ -1522,6 +1529,7 @@ decode_switches (int argc, char **argv)
ignore_patterns = NULL;
hide_patterns = NULL;
print_scontext = false;
+ fancy_chars = false;
/* FIXME: put this in a function. */
{
@@ -1866,6 +1874,10 @@ decode_switches (int argc, char **argv)
break;
}
+ case FANCY_CHARS_OPTION:
+ fancy_chars = true;
+ break;
+
case INDICATOR_STYLE_OPTION:
indicator_style = XARGMATCH ("--indicator-style", optarg,
indicator_style_args,
@@ -3749,7 +3761,26 @@ print_long_format (const struct fileinfo *f)
{
if (f->linkname)
{
+#ifdef HAVE_NL_LANGINFO
+ static const char *arrow = NULL;
+
+ if (!arrow)
+ {
+ arrow = " -> ";
+
+ if (fancy_chars)
+ {
+ const char *cs;
+ cs = nl_langinfo(CODESET);
+
+ if (cs && strcmp(cs, "UTF-8") == 0)
+ arrow = " \xe2\x86\x92 ";
+ }
+ }
+ DIRED_FPUTS_LITERAL (arrow, stdout);
+#else
DIRED_FPUTS_LITERAL (" -> ", stdout);
+#endif
print_name_with_quoting (f->linkname, f->linkmode, f->linkok - 1,
f->stat_ok, f->filetype, NULL,
f->stat.st_nlink, (p - buf) + w + 4);
@@ -4533,6 +4564,8 @@ Mandatory arguments to long options are mandatory for
short options too.\n\
-C list entries by columns\n\
--color[=WHEN] control whether color is used to distinguish
file\n\
types. WHEN may be `never', `always', or
`auto'\n\
+ --fancy-chars control whether fancy Unicode characters may be\n\
+ used in the output.\n\
-d, --directorylist directory entries instead of contents,\n\
and do not dereference symbolic links\n\
-D, --diredgenerate output designed for Emacs' dired mode\n\
--
1.6.4
Lennart
--
Lennart PoetteringRed Hat, Inc.
lennart [at] poettering [dot] net ICQ# 11060553
http://0pointer.net/lennart/ GnuPG 0x1A015CC4
Re: chmod feature request: setting different modes for files and directories
Pádraig Brady writes:
> Tobia Conforto wrote:
>> The same is true when someone
>> extracts some files from an archive or copies them over a removable
>> media, where permissions need to be reset to something sane, like 755/644:
>>
>
> current: chmod -R 755 another/path; find another/path -type f -exec chmod
> 644 {} +
current: find another/path -type f -exec chmod 644 {} + -o type d -exec chmod
755 {} +
> proposed: chmod -R d:755,f:644 another/path
>
> This case is more valid as it would be faster since you'd be traversing
> the branch only once.
Also only one traverse with find (which is more flexible here as well).
Andreas.
--
Andreas Schwab, sch...@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
Re: chmod feature request: setting different modes for files and directories
Tobia Conforto wrote:
> Dear coreutils maintainers,
>
> I'd like to ask for an often needed feature of chmod: the ability to set
> different modes for files and directories. I will briefly explain the
> need, and then propose a possible syntax.
>
current: find some/path -type d -exec chmod g+s {} +
proposed: chmod -R d:g+s some/path
I think the find syntax is more general/known/standardized.
So I don't think this use case warrants the change.
> The same is true when someone
> extracts some files from an archive or copies them over a removable
> media, where permissions need to be reset to something sane, like 755/644:
>
current: chmod -R 755 another/path; find another/path -type f -exec chmod 644
{} +
proposed: chmod -R d:755,f:644 another/path
This case is more valid as it would be faster since you'd be traversing
the branch only once. Though again it's more syntax.
TBH I never use chmod -R (or grep -R etc.) and always use
the more general `find`.
So I'd not be inclined to make this change.
cheers,
Pádraig.
