bug#14189: ls -d bug ??
Bernhard Voelker wrote: Bob Proulx wrote: `-d' `--directory' List only the name of directories, not the contents. This is most typically used with `-l' to list the information for the directory itself instead of its contents. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). Not bad, but I'm still missing the point that `-d' changes ls's behavior for *directory arguments* only. Hmm... If an argument is a directory then list only the name of the directory not the contents. Otherwise list the name of the file normally. Showing this around I had one person who was shocked to learn that directories were files. They really wanted this written so that it acted as if directories and files were completely different things. I countered that since directores were files, special files, that we shouldn't make the documentation lead people astray just to make it fit a wrong model of the machine. Furthermore, I don't think mentioning `-l' is of much relevance here. So this would melt down the first two sentences as follows: `-d' `--directory' For directory arguments, list only the information for the directory itself instead of its contents. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). That comment made the person who I worked with wordsmithing that line very sad. She was adamant that that tidbit about -l was the only useful part of the option description. And I think I agree that for someone reading the documentation and learning about it that the connection between -d and -l is important to point out explicitly. Maybe not this way but in some way I think we need to tie those two concepts together. And what about the usage() string? I'd bet this is still 95% where users are looking for. Something like the following perhaps? - -d, --directorylist directory entries instead of contents, - and do not dereference symbolic links + -d, --directoryfor directory arguments, list the entry itself + instead of contents, and do not dereference + symbolic links I think that is definitely an improvement. Because entries in the original I think isn't descriptive enough and makes people think contents instead of just the argument name. But frankly I still don't think it flows very well. If we are already pushed into three lines then let's make use of them. -d, --directory for directory arguments, list the name instead of contents, and do not dereference symbolic links Or perhaps better is: -d, --directory for directory arguments, list the directory name instead of directory contents, and do not dereference symbolic links Looking through other options for style I see: -L, --dereference when showing file information for a symbolic link, show information for the file the link references rather than for the link itself That entry has the same challenge. It is much wordier. The when showing file information for a symbolic link is the same task as our when showing file information for a directory. I like the shorter version for symbolic link arguments form. Perhaps as a separate improvement we could change it to: -L, --dereference for symbolic link arguments, show information for the target instead of for the link itself And then perhaps while gaining consistency of description without decreasing the usefulness of either entry we would gain back the line that we used above. Bob
bug#14189: ls -d bug ??
Bob Proulx wrote: Option 2 with much more description: `-d' `--directory' Do not list the contents of directories. List only the name. Without this option any non-option command-line arguments that are directories are treated specially and instead of the name the contents are listed. This option turns that behavior off and directories are only listed by name, the same as any non-directory file. This is most typically used with `-l' to list the information for the directory itself instead of its contents. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). Some local wordsmithing turned out the following as a better improvement. It lists what it does in the positive first. And removes the negative which was seen as being too confusing. `-d' `--directory' List only the name of directories, not the contents. This is most typically used with `-l' to list the information for the directory itself instead of its contents. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). Bob
bug#14189: ls -d bug ??
On 04/12/2013 08:06 AM, Bob Proulx wrote: Some local wordsmithing turned out the following as a better improvement. It lists what it does in the positive first. And removes the negative which was seen as being too confusing. `-d' `--directory' List only the name of directories, not the contents. This is most typically used with `-l' to list the information for the directory itself instead of its contents. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). Not bad, but I'm still missing the point that `-d' changes ls's behavior for *directory arguments* only. Furthermore, I don't think mentioning `-l' is of much relevance here. So this would melt down the first two sentences as follows: `-d' `--directory' For directory arguments, list only the information for the directory itself instead of its contents. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). And what about the usage() string? I'd bet this is still 95% where users are looking for. Something like the following perhaps? - -d, --directorylist directory entries instead of contents, - and do not dereference symbolic links + -d, --directoryfor directory arguments, list the entry itself + instead of contents, and do not dereference + symbolic links Have a nice day, Berny
bug#14189: ls -d bug ??
Eric Blake ebl...@redhat.com writes: bash-specific: $ (shopt -s nullglob; ls -d */ .[!.]/ .??*/) $ (shopt -s dotglob; ls -d */) 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.
bug#14189: ls -d bug ??
To: The most gracious and brilliant authors of the ever useful ls command. (The title is quite heartfelt - no sarcasm intended). I have to wonder. I've been using *nix of various kinds for nigh unto 15 years. I ran into an issue today that I've seen many times, and it still irks me. I've simply never taken the time to write to anyone about it. I assumed someone would report it and it would be magically fixed in the next version, but it never seems to. I've also seen several people elude to the same problem in forums, etc. Once in a blue moon, a person would like to view the subdirectories of the directory you are in, without seeing all the various files. Since you can use the ls command to view the files and directories that are contained in your pwd, one would THINK the intuitive method would be to type ls -d. Interestingly, the MAN page seems to indicate that this is the way to go, however, regardless of what directory you are in, if you type ls -d you don't get the expected result, but rather you get: . Which is like ls is telling you, Yup, you are in a directory! Wull DUH, like I couldn't figure out that I was in a directory. If I wanted to get more info on that I'd type pwd ! tree -dx ALMOST gives you the desired outcome, except it includes all the subdirectories of the subdirectories. ls -d, I would think, would tell you the same data that ls would tell you, minus the individual files. (In other words - show all the data with a d in the permissions, but not show the ones that don't have a d in the permissions). I'm not afraid to admit I may be missing the whole point (pardon the pun). Is it me, or am I just not understanding the importance of the . , and how that . might change from one directory to another? WHY does ls -d just give me a dot? Is that dot supremely important? Is there some reason it can't give me what (it appears) the manual says (and what makes sense) it should? Ray Dall Radio Frequency Engineer Author: Electronics for Sound Engineers This email sent via a virus free Linux computer.
bug#14189: ls -d bug ??
Hello Ray, Others can provide more detailed information about the rational of the dot file, but regarding your questions: r...@electronicstheory.com wrote, On 04/11/2013 02:17 PM: Once in a blue moon, a person would like to view the subdirectories of the directory you are in, without seeing all the various files. find -type d will list all directories (but will do so recursively). find -maxdepth 1 -type d will list only directories immediately under your current directory. Since it's once in a blue moon (as you've said), I guess there's no short form for that. If you need the extended information that ls provides: find -maxdepth 1 -type d -print0 | xargs -0 ls -ld ... Interestingly, the MAN page seems to indicate that this is the way to go, however, regardless of what directory you are in, if you type ls -d One use-case for -d is to show the information about the directory, instead of the *content* of the directory. Compare: ls -l /etc vs.: ls -ld /etc HTH, -gordon
bug#14189: ls -d bug ??
tags 14189 + notabug close 14189 thanks http://www.gnu.org/software/coreutils/faq/#ls-_002dd-does-not-list-directories_0021 r...@electronicstheory.com wrote: Once in a blue moon, a person would like to view the subdirectories of the directory you are in, without seeing all the various files. Thank you for your report. However what you are reporting is due to a misunderstanding of the usage of the command. Since you can use the ls command to view the files and directories that are contained in your pwd, one would THINK the intuitive method would be to type ls -d. But that is not correct. And it isn't as documented. Interestingly, the MAN page seems to indicate that this is the way to go, You have fallen into a trap. The computer is executing a program and does *exactly* what it was programmed to do. The documentation is written to say exactly what the program does. But you are thinking like a human and making an interpretation and an extrapolation based upon what you *want* it to do. Those are different things. The GNU ls documentation says this: `-d' `--directory' List just the names of directories, as with other types of files, rather than listing their contents. Do not follow symbolic links listed on the command line unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. The GNU ls man page says: -d, --directory list directory entries instead of contents, and do not dereference symbolic links The online standards documents say: http://pubs.opengroup.org/onlinepubs/009695399/utilities/ls.html -d Do not follow symbolic links named as operands unless the -H or -L options are specified. Do not treat directories differently than other types of files. The use of -d with -R produces unspecified results. Each and every one of those applies the -d option to the arguments of the ls command. But what are the arguments to ls? If you type in ls with an argument then there is no doubt. $ mkdir foodir $ touch foodir/foofile1 $ ls foodir foofile1 At that point there is no doubt. You are asking it to list foodir. Let's apply the -d option. $ ls -d foodir foodir The -d option clearly applies to foodir. Therefore it prevents it from listing the contents. It lists only the name of the directory. This is as documented for -d that it lists only names and using -d prevents it from listing the directory argument contents. But what happens if you don't give ls an option? What is the default argument to ls? The GNU ls documentation says: 10.1 `ls': List directory contents == The `ls' program lists information about files (of any type, including directories). Options and file arguments can be intermixed arbitrarily, as usual. For non-option command-line arguments that are directories, by default `ls' lists the contents of directories, not recursively, and omitting files with names beginning with `.'. For other non-option arguments, by default `ls' lists just the file name. If no non-option argument is specified, `ls' operates on the current directory, acting as if it had been invoked with a single argument of `.'. That last line says it. Let me repeat it for emphasis. If no non-option argument is specified, `ls' operates on the current directory, acting as if it had been invoked with a single argument of `.'. If no arguments are specified then ls lists '.' as if it had been invoked ls .. however, regardless of what directory you are in, if you type ls -d If you run ls -d then we know from the documentation that it is the same as saying ls -d . and that will simply list the name of it because the -d option says only list the names of directories. Therefore the expected behavior is that it must only list the name of the '.' directory. you don't get the expected result, but rather you get: . Unfortunately you had incorrect expectations! :-) Any other result would be a bug. I hope I have convinced you that that ls is doing the right thing here and behaving as documented even if it isn't doing what you want it to do. This is a common misunderstanding and is one of the FAQ entries. Please read the FAQ entry here: 17 ls -d does not list directories! http://www.gnu.org/software/coreutils/faq/#ls-_002dd-does-not-list-directories_0021 Wull DUH, like I couldn't figure out that I was in a directory. If I wanted to get more info on that I'd type pwd ! If you didn't want it to list only the name of the directory and not the contents then why did you use the -d option? Since -d specifically prevents it from listing the contents. ls -d, I would think, would tell you the same data that ls would tell you, minus the individual files. (In other words - show all the data with a d in the permissions, but not show the ones that don't have a d
bug#14189: ls -d bug ??
On 04/11/13 11:17, r...@electronicstheory.com wrote: Is there some reason it can't give me what (it appears) the manual says (and what makes sense) it should? Sounds like there's a bug in the manual; it shouldn't say that ls -d outputs only directories. Can you please mention the wording you're talking about? To get something like what you want, you can use this command: ls -d */ or maybe: ls -d */ .*/
bug#14189: ls -d bug ??
On 04/11/2013 03:13 PM, Bob Proulx wrote:
If you didn't want it to list only the name of the directory and not
the contents then why did you use the -d option? Since -d
specifically prevents it from listing the contents.
ls -d, I would think, would tell you the same data that ls would tell you,
minus
the individual files.
(In other words - show all the data with a d in the permissions, but not
show
the ones that don't have a d in the permissions).
Perhaps you want this?
$ ls -log | grep ^d
$ ls -log | grep -v ^d
Or one of these:
$ find . -maxdepth 1 -type d -ls
$ find . -maxdepth 1 -type d -exec ls -logd {} +
Or you could use this to approximate things:
$ ls -d */
the trailing slash forces the shell to filter out non-directories as
part of expanding the glob, and then list just the names instead of the
contents of all remaining directories. But as written that only lists
non-hidden directories. If you don't mind listing '.', you can get
closer with:
$ ls -d */ .*/
But for a full list of all subdirectory names excluding '.' and '..',
you need three globs; and either a shell option that suppresses a glob
that has no match, or ignoring the errors when ls tries to warn you when
a glob doesn't match:
Portable (but risks hiding errors):
$ ls -d */ .[!.]/ .??*/ 2/dev/null
bash-specific:
$ (shopt -s nullglob; ls -d */ .[!.]/ .??*/)
All the sudden, the 'find' alternative suddenly seems nicer :)
--
Eric Blake eblake redhat com+1-919-301-3266
Libvirt virtualization library http://libvirt.org
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bug#14189: ls -d bug ??
On 04/11/2013 03:31 PM, Eric Blake wrote: But for a full list of all subdirectory names excluding '.' and '..', you need three globs; and either a shell option that suppresses a glob that has no match, or ignoring the errors when ls tries to warn you when a glob doesn't match: Portable (but risks hiding errors): $ ls -d */ .[!.]/ .??*/ 2/dev/null Be aware that this also runs the risk of generating too long of a command line if the globs expand to a lot of names; while find specifically avoids exceeding command line length limits. On the other hand, while ls defaults to sorting its output, find does not; so if you need sorted output, you have to start considering the use of non-POSIX extensions such as GNU find's -print0 and sort's -z to generate and sort the list with unambiguous terminators, if you are worried that any of the names found might contain a newline in the name. -- Eric Blake eblake redhat com+1-919-301-3266 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature
bug#14189: ls -d bug ??
Bob Proulx wrote: 10.1 `ls': List directory contents == The `ls' program lists information about files (of any type, including directories). Options and file arguments can be intermixed arbitrarily, as usual. For non-option command-line arguments that are directories, by default `ls' lists the contents of directories, not recursively, and omitting files with names beginning with `.'. For other non-option arguments, by default `ls' lists just the file name. If no non-option argument is specified, `ls' operates on the current directory, acting as if it had been invoked with a single argument of `.'. That does seem like it could use some improvement. It makes the mistake of burying the lead by putting that last sentence so far down. I like the BSD man page version much better. Is there a way we can simplify this but still keep it descriptive? The FreeBSD man page is much better for this description. How about this? (I will work it up into a texinfo patch afterward.) The `ls' program lists information about files. If the file being listed is a directory then the contents of the directory is listed. If no non-option command-line arguments are specified then 'ls' operates on the current directory, acting as if it had been invoked with a single argument of `.'. `ls' is the same as `ls .'. For each non-option command-line argument that is not a directory `ls' lists the file name. For each non-option command-line argument that is a directory `ls' lists the names of files in the directory. Files starting with a '.' are ignored and hidden. WDYT? `-d' `--directory' List just the names of directories, as with other types of files, rather than listing their contents. Do not follow symbolic links listed on the command line unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. And then perhaps this following. Also the above does not describe the interaction with -R. Option 1: `-d' `--directory' Do not list the contents of directories. List only the name. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). Option 2 with much more description: `-d' `--directory' Do not list the contents of directories. List only the name. Without this option any non-option command-line arguments that are directories are treated specially and instead of the name the contents are listed. This option turns that behavior off and directories are only listed by name, the same as any non-directory file. This is most typically used with `-l' to list the information for the directory itself instead of its contents. Do not follow symbolic links unless the `--dereference-command-line' (`-H'), `--dereference' (`-L'), or `--dereference-command-line-symlink-to-dir' options are specified. Overrides `--recursive', (`-R'). I like the conciseness of the first. But the extra description in the second seems useful. WDYT? Bob
