Re: dired without -l, wdired fails

[Tassilo Horn <tassilo@member.fsf.org>]

Andreas Roehler <andreas.roehler@online.de> writes:

Hi Andreas,

>>> if `dired' is called without the `-l' switch, wdired... no longer
>>> works, buffer isn't editable.
>> 
>> Does dired work without -l?  At least the docs say it MUST contain
>> -l.
>> 
>> ,----[ C-h v dired-listing-switches RET ]
>> | dired-listing-switches is a variable defined in `dired.el'.
>> | Its value is "-aDlh"
>> | 
>> | Documentation:
>> | Switches passed to `ls' for Dired.  MUST contain the `l' option.
>> | May contain all other options that don't contradict `-l';
>> | may contain even `F', `b', `i' and `s'.  See also the variable
>> | `dired-ls-F-marks-symlinks' concerning the `F' switch.
>> | On systems such as MS-DOS and MS-Windows, which use `ls' emulation in Lisp,
>> | some of the `ls' switches are not supported; see the doc string of
>> | `insert-directory' in `ls-lisp.el' for more details.
>> `----
>
> you are right. It's a convenience-bug anyway IMO.
>
> IIRC `dired' basically displays the output of shell-command `ls
> [options]' in a buffer, afterwards working with, send it back to the
> shell.
>
> From this I never understood this limitation, which looks inconvenient
> in many respects.

By default the switches also contain the -D option, which are described
as follows:

,----[ (info "(coreutils)What information is listed") ]
| `-D'
| `--dired'
|      With the long listing (`-l') format, print an additional line after
|      the main output:
| 
|           //DIRED// BEG1 END1 BEG2 END2 ...
| 
|      The BEGN and ENDN are unsigned integers that record the byte
|      position of the beginning and end of each file name in the output.
|      This makes it easy for Emacs to find the names, even when they
|      contain unusual characters such as space or newline, without fancy
|      searching.
`----

That option requires -l, although I don't see why.  But that may be the
cause.

Bye,
Tassilo