Re: mv command usability: rename file and create dest dir

[Arsen Arsenović]

Sergey Ponomarev <stokito@gmail.com> writes:

> Hi again,
>
> So will you accept a patch with adding the * as a basename replacement for
> DEST in cp and mv?
>
> And speaking about the second usability problem about creation of a non
> existing DEST directory.
> There is install command which makes exactly this but also support setting
> owner:
>
>        -D     create  all  leading  components of DEST except the last, or
> all
>               components of --target-directory, then copy SOURCE to DEST
>
>        -g, --group=GROUP
>               set group ownership, instead of process' current group
>
>        -m, --mode=MODE
>               set permission mode (as in chmod), instead of rwxr-xr-x
>
>        -o, --owner=OWNER
>               set ownership (super-user only)
>
> It's great and actually looks like this command is just an extension of cp.
> But while the cp is well known the install command is used rarely. I never
> looked into it and never saw its man. I guess many users too.

install is used a lot, especially by build systems.  It is also quite
easy to encounter in the manual, sitting in the basic operations section
right next to cp:

  Next: Special file types,  Prev: Directory listing,  Up: Top
  
  11 Basic operations
  *******************
  
  This chapter describes the commands for basic file manipulation:
  copying, moving (renaming), and deleting (removing).
  
  * Menu:
  
  * cp invocation::               Copy files.
  * dd invocation::               Convert and copy a file.
  * install invocation::          Copy files and set attributes.
  * mv invocation::               Move (rename) files.
  * rm invocation::               Remove files or directories.
  * shred invocation::            Remove files more securely.
  -----Info: (coreutils)Basic operations, 17 lines --Top----------

> What if we just merge these two commands? That will simplify things.
> It looks like there are two conflicting options -d -s so we can't just make a
> symlink to cp but anyway it's easy to just wrap the cp.

IIRC, internally, the two already share a significant portion of the
code.

> Will you consider a patch with the change?
>
> This two additions while being relatively small will make more effective
> interacting with command line and writing scripts.
>
>
> On Sat, Jul 1, 2023 at 8:19 PM Sergey Ponomarev <stokito@gmail.com> wrote:
>
>> Workaround: use Brace Expansion:
>> mv /tmp/{file1,.bak}
>> or
>> mv /tmp/{file1,.bak}
>>
>> It wasn't intuitive, that's why I didn't figure it out in the first place.
>> Autocomplete doesn't work, but this is a bash issue.
>>
>> Still, the placeholder would be kind of more clear but it's an additional
>> feature so you probably WONTFIX it.
>>
>>
>>
>> On Sat, Jul 1, 2023 at 7:23 PM Sergey Ponomarev <stokito@gmail.com> wrote:
>>
>>> Thank you for the fast response. Nice tricks, didn't know about the
>>> direxpand. Probably most regular users don't know either :(
>>> As you may see, even with a workaround this usability can be improved.
>>> So what about having the simple solution in place?
>>> 1. Use placeholder like asterisk to refer the source dir inside of the
>>> dest dir
>>> 2. Use -F arg to create directory if not exists
>>>
>>> Have a nice weekend
>>>
>>> On Sat, Jul 1, 2023 at 6:44 PM Glenn Golden <gdg@zplane.com> wrote:
>>>
>>>>
>>>>
>>>> On Sat, Jul 1, 2023, at 09:03, Bernhard Voelker wrote:
>>>> > On 7/1/23 14:12, Sergey Ponomarev wrote:
>>>> >  > To rename a file a user need to use mv command and specify the DEST
>>>> dir:
>>>> >  >
>>>> >  >      mv /some/very/long/path/file /some/very/long/path/
>>>> >  >
>>>> >  > This makes it not so easy to use when typing a command but also
>>>> makes a
>>>> >  > script line longer.
>>>> >
>>>> > Assuming you meant
>>>> >
>>>> >    $ mv /some/very/long/path/file /some/very/long/path/file2
>>>> >
>>>> > as in the other example - this could be done with:
>>>> >
>>>> >    $ cd /some/very/long/path && mv file file2
>>>> >
>>>> > or (with GNU coreutils' env):
>>>> >
>>>> >    $ env -C /some/very/long/path mv file file2
>>>> >
>>>> > Have a nice day,
>>>> > Berny
>>>>
>>>> If you use bash and if your long paths are consistent (i.e. often
>>>> referring
>>>> to the same source or destination each time) then another approach is to
>>>> just
>>>> enable the bash 'direxpand' option, define some short envars in your
>>>> .bash_profile or .bashrc, and use those to facilitate commandline (and
>>>> script) operations, e.g.
>>>>
>>>>   export p1=/long/path/to/some/frequently/accessed/directory
>>>>   export p2=/another/long/path/to/a/frequently/accessed/directory
>>>>
>>>> Then, for cmdline ops, just typing
>>>>
>>>>   $ mv $a/<tab>
>>>>
>>>> immediately expands $a (inline on the commandline) to
>>>>
>>>>   $ mv /long/path/to/some/frequently/accessed/directory/
>>>>
>>>> and you can then tack on "$b" (or any other destination).
>>>>
>>>> The 'direxpand' option provides nice immediate feedback that the envar
>>>> you
>>>> selected is the correct one (among, presumably, several 1-letter envars
>>>> you've defined like this for various long paths of interest.)
>>>>
>>>> I use this approach frequently in my own workflow when dealing with
>>>> annoyingly long but consistent paths.
>>>>
>>>> Glenn
>>>>
>>>>
>>>>
>>>
>>> --
>>> Sergey Ponomarev <https://linkedin.com/in/stokito>,
>>> stokito.com
>>>
>>
>>
>> --
>> Sergey Ponomarev <https://linkedin.com/in/stokito>,
>> stokito.com
>>


-- 
Arsen Arsenović

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