Re: [Cscope-devel] Adding filenames with spaces and options to cscope.files

[Hans-Bernhard B. <br...@ph...>]

On Sat, 17 Nov 2001, Steven Elliott wrote:

> Currently cscope.files does not support filenames with spaces as it 
> considers the filenames in cscope.files to be separated by white space:

That's an old issue with most, if not all traditional Unix tools:  
filenames are allowed to contain characters that the tools can't really
cope with easily, and certainly not automatically. That's what caused the
necessity for hacks like '-print0' in GNU find. You'll find the same type
of problem in traditional 'tar', IIRC. Even the shell itself needs human
assistance ("quoting" around blanks in filenames) to deal with such
filenames.

There are those who take this kind of problem as the reason to claim that
all kind of inband-signalling should always be considered evil.

>  From the code (src/dir.c) it looks like cscope reads cscope.files one 
> token at a time.  

It reads whitespace-separated words, just like the shell does in default
conditions (IFS="<space><tab><newline>").

> Each token is considered to either be an option, if it begins with
> "-", or a filename, if it does not begin with "-".  So, filenames that
> either have spaces in them or begin with a "-" are not supported.

Right. Same as they would not be supported in the command line of just
about any other Unix tool without special help (--> the "--" option to
allow names beginning with a minus, and quoting to allow whitespace).

> In order to support such filenames would it be reasonable to place the 
> following restrictions on cscope.files?:
>      1) Each filename must appear on a separate line.

I don't think that's a good idea.  Placing additional restrictions on
existing users' "cscope.files" breaks compatibility.  I, for one, am in
the habit of generating my cscope.files via 'echo *.[ch]', so it does
contain lots of names per line.

>      2) Options, if any, must appear at the beginning of cscope.files.

Same problem.

> I'm guessing that the most common case is for cscope.files to simply be 
> the output of "find".

The most common yes. But can we really discard the uncommon ones just like
that?  I don't think so.

I think it'd be more sensible to imitate the shell's way of treating
these.  After all, cscope.files is essentially just an extra source of
command line input, right now.  It works as if the user had typed

	cscope `cat cscope.files`

So it makes sense to treat it like the shell would treat command lines. We
would require all unusual filenames to be quoted. 'find' output could
easily be massaged to contain the quotes, where necessary.

-- 
Hans-Bernhard Broeker (br...@ph...)
Even if all the snow were burnt, ashes would remain.