On Fri, 2004-11-26 at 21:13, Christian Mayrhuber wrote: > Regarding namespace unification + XPath: > For files: cat /etc/passwd/[. = "joe"] should work like in XPath.
I don't understand this. Why would you need the "."? And why the / between passwd and [ ? I would prefer (as was suggested earlier in the thread) that the syntax for the entry for joe in the passwd file should be /etc/passwd/joe and the if you want to select joe's full name, then it should be /etc/passwd/joe/fullname and it would result in e.g. "Joe Smith" and /etc/passwd/joe/shell whould be the shell joe uses. Of course something would have to tell the system that the passwd file has one line for each user, and that fields within a line are separated by ":"s and what the names of the fields are (e.g. the first field is called "user"). And when you select inside the /etc/passwd file (or this type of file) then the default interpretation of joe is that "user" should be used to select the line. So by default, /etc/passwd/joe should be equivalent to /etc/passwd[user = "joe"] But you should be able to select based on fullname too: /etc/passwd[fullname = "Joe Smith"] and /etc/passwd[shell = "/bin/bash"]/user should give you the user names of all users whose shell is /bin/bash, right? > But what to do with directories? > Would 'cat /etc/[. = "passwd"]' output the contents of the passwd file > or does it mean to output the file '[. = "passwd"]'? I don't really see the point of this . = "passwd" syntax. > If the first is the case then you have to prohibit filenames looking > like '[foo bar]'. I think so. > If the shells wouldn't like * for themself, I'd suggest something like > cat /etc/*[. = "passwd"] > This means: list all contents and show the ones where filename = "passwd". but isn't that just /etc/passwd ? why complicate it? > For the contents of /etc/passwd the following could become possible: > 'cat /etc/passwd/*[. = "joe"] > 'cat /etc/passwd/[EMAIL PROTECTED] = "/bin/tcsh"] no, I think it should be cat /etc/passwd[shell = "bin/tcsh"] why the *? and why the @? an attribute? why not simply a part of the line with / ? > To change all tcsh entries to bash: > echo -n "/bin/bash" > /etc/passwd/[EMAIL PROTECTED] = "/bin/tcsh"]/@shell I would say echo -n "/bin/bash" > /etc/passwd[shell = "/bin/tcsh"]/shell > What about mapping the contents of files into "pure" posix namespace? Yes, that is exactly what I am suggesting, except that I would like to extend the POSIX syntax by stealing some useful syntactic bits from XPath. > XML is basically a tree, too. > Notes: > 1) "...." below is the entry to reiser4 namespace. > 2) # denotes a shell command > For example: > > # cd /etc/passwd/ > # ls -a * > . .. .... joe root > # cd joe > # ls > gid home passwd shell uid yes, but where is the username? that would be the first one listed here, right? > # cat shell > /bin/tcsh > # cd ../.... > # ls > plugins > > I guess an implementation in reiser4 would require some > mime-type/file extension dispatcher plus a special > directory plugin for each mime-type.
